Video... must see to believe

[azn_romeox]

Video (http://www.nissdata.com/video/Enthalpy-testride.wmv)

[-E-]

secret services 240 is so sick :eek: I need to stop by their shop

[Nismos14]

:faint: never seen the needle move that fast in any car holy mother of god :aw: :boink:

[s13rookie]

real nice vid, my needle doesnt move that fast in nuetral

[YellwMonky]

:eek: :eek: :eek: :eek:

that's crazy !!

does anyone know more about that car ? sr or ka ? i would like to look more into what that car has !

[-E-]

Originally posted by YellwMonky
:eek: :eek: :eek: :eek:

that's crazy !!

does anyone know more about that car ? sr or ka ? i would like to look more into what that car has !

SR
Link (http://www.tamparacing.com/forums/showthread.php?threadid=94013)

[Got Sileighty?]

:eek: :D :eek: :D :eek: :D :eek: :eek: :eek:

oh wow!!! to me it seemed like he shifted to 4th right when he was about to peg the speedo (~110mph) thats nuts!

[Red]

well his old hp was like 454hp like 390tq so I wonder how much more it has from his new parts.... At max I would guess it would be like 500hp.. Which is not bad at all. But I am waiting to see a 600-700hp 240sx... Now that would make me look twice. And I would like it even better if it was a KA.

[method2833]

just like the guy in the video says in the end WOW!:eek: :bowdown:

[Bill Roberts]

Yep, that is the power. 55 in first, 95 in second, they got the serious 450"HP going on.

Transmission sounds like it is coming unglued. You cannot get many runs like that and have trannies hold up.


Sounds like a twin turbo RB2.6 on line there. But not....



But I think it is just a 2.0DET on line...they say it is a 180SX.


Now , that is why they call us the godzillas of cars.


Bad A S S eh?

Honda and acuras really do not realize this.


As I said earlier, we got it made.

I saw a video of a skyline that would make this seem slow. It was a 8 second qtr in a sky. Too tough.



Does the transmissions always sound like they are coming apart with this much power?

My Old Rock crusher M22 in my chevys back in the 70's had no sinc-ros and were loud but DAMN!
Mine is no where near that or ever will be.

I am quite pleased now with a 14.8/ 95MPH running a KA24DE


That is a seriously fast car.


Skyline type power.
I wonder what our Japanese friends have to say about that!

Looks to me like a 10.3/145


Been close, not in mine.


I do a meger 40 in first, 69 in second, 94 in 3rd....well you know the rest.


I love that video. Badd A$$

[Bill Roberts]

PS:


See the engine.

Quick clip (http://65.34.69.131/video/Enthalpy-Firstrun.wmv)

And look at some of this action as well (if you haven't already)

http://www.3rotor.com/creek_17052000.htmfun (http://www.3rotor.com/creek_17052000.htm)


Oh damn, I forgot you got to pay to play there....sorry...really. I did not remember that (edit)

[Fibercus]

whoa :bowdown:

[Bill Roberts]

opps typo. I have a lonely KA24E (no D)

Could no go back and edit (sorry)

[KiDyNomiTe]

Originally posted by Bill Roberts
opps typo. I have a lonely KA24E (no D)

Could no go back and edit (sorry)

you ran 14.8 in a SOHC any mods or just a good driver?

[Bill Roberts]

I have had the car now since Nov 2001 and have had to nickle and dime it along to make it a reliable daily driver. Since I am now just getting in it...(investigating) the engine has obviously been torn down before. I see red silicone almost everywhere for gasket sealer. The dude that had it lived in Tampa and all the recieps I got were basically maintenance. Something obviously was done to it. I am going to see if I can find out what. It runs pretty fast, eating V6 stangs and v6 cameros very easy, I can get the hole shot on a lot of rides out there but I reserve performance driving for the track. Last run was a [email protected] It has the limiter on it still but it can get to 7300RPM before it kicks in on upshifts (solid 40 in first) and I did take it to the 115 and it was just getting in the power band about that time it shut down.

I suspect it has but not proven yet:

Larger injectors.
Port and polished heads.
High output fuelpump.
Different MAFS

It hauls, the guy that had it before was an enthusist and bought it new but he passed away in 2000 and I never met him. Just bought it from a family member. It comes on line much harder than one guy that drove it once expected. He had a 92 (dual overhead cam) and said, something radical has been done and he couldn't figure it out.
I know 14.8 is not that fast and I was able to get better times than road and track ever did when I had my ZR-1 Vette. Driving has a lot to do with the times. When to shift, how to shift, etc.

I also feel I could get about 30 more HP out of that engine with some intake and exaust mods. I plan on dyno testing it sometime this summer. Who knows what all was done to it really. Looks bone stock from eyeballing the engine bay.

It was Built in MAY of 1989

[transient]

Originally posted by Red
well his old hp was like 454hp like 390tq so I wonder how much more it has from his new parts.... At max I would guess it would be like 500hp.. Which is not bad at all. But I am waiting to see a 600-700hp 240sx... Now that would make me look twice. And I would like it even better if it was a KA.

It's been done, but it wasn't an SR... It was a CA :D (http://www.nissaninfiniticlub.net/forums/showthread.php?s=&threadid=15195)

[-E-]

Originally posted by transient
It's been done, but it wasn't an SR... It was a CA :D (http://www.nissaninfiniticlub.net/forums/showthread.php?s=&threadid=15195)
o damn

[Apparition]

:eek: That's unbelievable. The speedo was buried by 3rd gear!

[Jeff240sx]

Originally posted by Bill Roberts
Yep, that is the power. 55 in first, 95 in second, they got the serious 450"HP going on.
I do a meger 40 in first, 69 in second, 94 in 3rd....well you know the rest.

That's funny... horsepower doesn't equate to a faster speed in a given gear. Horsepower allows you to overcome aerodynamic and frictional forces, and rev faster. Gear ratios determine the speed in a gear. The only difference between your stock 240 and theirs *may* be a 3.91:1 final drive, which doesn't equal the difference shown above.
-Jeff

[WhiteNissanS13]

what program are you guys watching it with??? my windows media player is only playing the sound part of it? what codec do i need i downlaoded divx but that wont work either. help:aw: i wanna see what this is all about!

[Bill Roberts]

I guess my point is they have the HP and the revs. Probably turning aroud 8500 to 9K. The tach is only hitting aroud 7 though ???

May be a tall gear.

7K on mine is 40 in first. Really, nothing above 5500 on my car is worth going there, it is just revs, the powerband has already peaked long before 7K.

I was lurking around and found a dyno chart that may have been their engine, might have been some other car..but looks like about 410 HP was produced on that chart.

www.nissdata.com

The dyno chart seems to only be marked out to 7350

I am surprised my car =can= hit 7300 before the fuel shutdown. I don't like taking it up there..it was not meant to be on that setup.

WhiteNissanS13, My computer at work does the same thing. Blank screen and sound only.

Can you watch other vids on it? Your video card may not be up to speed.

Winamp will play it too with the right plug.

Dude is turning on the speed pretty hard.

[transient]

grab the latest version of windows media player, that might help.

[azn_romeox]

I've read hes using a 4:3 final gear ratio.

[logo20]

I am quite pleased now with a 14.8/ 95MPH running a KA24DE
isn't it ka24e? with no lsd?
this is all I gotta say.
:bs:
edit: the double spacing is kind of anoying too.

[Bill Roberts]

You do not have to believe. Port and polished, bored 40 over, 7300RPM, Non stock cam (found that receipt today) it does it, wanna come run? It is an E not a DE, if you took the time to read the postings.

Doublespace is fine. Easier on the eyes.

[Bbandit]

Originally posted by Bill Roberts
You do not have to believe. Port and polished, bored 40 over, 7300RPM, Non stock cam (found that receipt today) it does it, wanna come run? It is an E not a DE, if you took the time to read the postings.

Doublespace is fine. Easier on the eyes.

actually, i believed you.. you know your stuff :p its all about the driver, and you have to pass down your knowledges to me :bow:

[Strider]

I believe you Bill:D Hey, about you get a vid though of your car. That might get the non believer(s) to be hush up and plus I juss like watching vids of 240's, gives me something to do.

[Bill Roberts]

That sounds like a great idea!

Next time I take it to the track (2 weeks or 3 weeks) I will get one of my buddys to video it. I do not have a camera.

Bear in mind how fast the car that started this link. Their was a passenger aboard :eek:

A passinger clearly adds 7 tenths of a second to a quarter mile.
Weight is your worst nighmare when it come to speed. I think I can do a shade better than the 14.8.
Problem is:

3rd to 4th shift is right at the line. If I shift into 4th earlier, I loose speed. If I make the shift right before the line, I get 2 1/10ths. If I had a slightly shorter gear (maybe lower profile tires) I could have a little 4th gear action that may be meaningful.

I think it is the pinacle of that engine right now. Without a turbo, it is about flat out. Intake and exaust mods would not help it much at this point. The exaust is open on runs (cutoff)

[s0ldats]

Originally posted by Bill Roberts
You do not have to believe. Port and polished, bored 40 over, 7300RPM, Non stock cam (found that receipt today) it does it, wanna come run? It is an E not a DE, if you took the time to read the postings.

Doublespace is fine. Easier on the eyes.


i got your back bill :)

[mrmephistopheles]

Originally posted by logo20
isn't it ka24e? with no lsd?
this is all I gotta say.
:bs:
edit: the double spacing is kind of anoying too.


Go flame someone else. :mad: :hammer:

[scandalcat1]

logo20, please pick on someone else. there is no need to flame anybody around here. bill does understand the fundamentals of engines and surely the s13, as he stated in another thread, he reads a lot into the car, and that is something we should all strive for.

As for the car in the video, i don't know what to say...i am awestruck at the sheer speed.

[Bill Roberts]

Thanks fellows. it is lame to flame someone that will never post anything on this forum other that fact that I know "ME"(I have no reason to make up stories, it does not contribute anything to this board to do so) besides, If I wanted to really bull$hit, I could have made up a number like 14.1 or 13.8 which we know is hardly achiveable under such circumstances. Especially since I am now just learning all the crap that was done to my car prior to posting what I thought I knew it had. I got some more receipts that are pretty amazing. Like oil pump mods, shaving the block, larger injectors, updated fuel pump, larger gas lines, Weight taken off, and all kinds of stuff that this late enthusist had done to this car. Believe me, it is quite quick for what it is. I have driven supercars. I Owned a ZR-1 vette in 94. We modded it then.


14.8/95MPH in the quarter is highly achiveable with this engine and car. Stock GMC trucks with 454CID and automatics could do low 14's and even mid 13's right off the showroom floor with 400 LBS of rock crete in the bed.

Goddamn, I took a Maverick 4 door sedan with a strait six in 1979 (73 model with shag carpeting factory)(250CID) to a 15.9 because I knew when to shift and how!!!

Curise-o- matic auto C-5 tranny, it rocked, The car would do 124MPH and it was a 4X8 sheet of plywood for aerodynamics. Nasty.

I have driven an F1 Racer (insane speed) at Homestead for kicks and grins, not flat out, but a solid 170MPH aroud the track (top speed was 238MPH) BTW, it was a Lola/Olsmobile prototype. Good frineds to know. Date, 1993.

I am not a good enough driver to take that to the top, but my 240sX? I can extract every nano second from it due to experience.

www.fiveflagsspeedway.com

If I had a dollar for every lap I have driven there, we could buy a 91 Lola/Mercedes.

I am not a race car driver but I have freinds that are fairly deep into it that trust me behind the wheel for another Eval/Dem.

I feel it is nice to be trusted.

I would like nothing better than to do babysteps personally with our cars and learn about them and be able to discuss dialog with "knowns" not a bunch of talk..
I got this car after a divorce, knowing full well that it came from a major enthusiastic person that happened to die from a blood condition. I bought it through his family, and I am still sifting through the records.

Some of them are just now coming to light. Full bottom end rebuild at 54K miles, etc.

Wholesale bashing of somebodys facts are not appreciated IMHO.

I am stil learning =WHY= this car is running so good. My Idle problem is due to the cam. It has to idle at 1.2K or else. It shakes violently.. It moves the gearshift at 2.2K RPM in Neutral 1 inch back and forth...uncapped it sounds like a dragster at that speed, popping and all. The cut-out is a device that is manual. You pull a lever out and it opens the exaust before the cat. Sounds great, all runs, done this way. It is a high revver. (7300RPM, 40MPH, 69MPH, 94MPH 1st, second, third))

It cannot idle at 700RPM without backfireing and cutting out. The lift and duration of the cam that was installed will not acccomidate a slower idle. 1200 is it.

I feel that this case is closed, I will be happy to produce a video (in due time as I can) and consider this kind of flagrant bashing a dead issue.

Am I overreacting? NO, If someone wants to question me, come see it in the flesh. I am most amazed at how he came to THAT conclusion actuallty.

If a cat wants to get a 12 second quarter out of a KA24E, I guess with the right money, weight take-offs and the right driver , without limited slip or a turbo, it could possably be done.


Proper head work and valve timing can "triple the horsepower" at different RPM's.

How do I know this?

David Barnett that has shaved, ported and polished top fuel dragester heads , we talk all the time. He told me tonight that with certain grinding, he personally can get 280HP easy out of the motor.

All it takes is truth, which is all I do on this fine board.

Perhaps some driving pointers is something that our "friend" needs to realise. He must remember, I was running cars over 160MPH (1/4) in 1976. That should count for something...even stupidity, I might add.

I appreciate you guys listening and learning. The BS factor is basically from a non-achievers attitude. He may never get there, or want to.

You know what, flaming is something I do not take kindly to. I hope no one else does either. If you have something to discredit, don't get your info off the web. Live and learn a person in the flesh, don't trust the folks that have "absolute reference from the web" to answer the "truth"


Sorry folks I waisted this much time writing a book, but you know what? Next flamer that disses me, I just hit the report post button and call it a day. Being new here has certain disadvantages, telling the truth has the advantages.

Enough for now.

I promise not to reply to negative posts, I just want the record set strait here.


To the B U l L S h i t flag...

Think before you stink.:(

[Steeles]

one more flag must be raised here;

:owned:

[logo20]

I've been using 1/4 calculator, and it takes a 2680lbs car 160rwhp or 190fhp to run 14.8 in the 1/4 mile. so let's talk hp. sykikchimp's car has 122whp with intake and exhaust, dousan's car has 136whp with exhaust,(higher because i think he has lsd and a newer car). now a 89-90 has 15hp less, so a 89-90 stock would probably have a little over 100whp.
now,
"Port and polished, bored 40 over, 7300RPM, Non stock cam (found that receipt today)" [plus more fuel delivery as he stated]
those mods gave him almost 60whp? :faint:

[Fibercus]

A LOT more factors go into a 1/4 mile time beside JUST HP + wieght....

but ya it makes sense

[Steeles]

Originally posted by logo20
I've been using 1/4 calculator, and it takes a 2680lbs car 160rwhp or 190fhp to run 14.8 in the 1/4 mile. so let's talk hp. sykikchimp's car has 122whp with intake and exhaust, dousan's car has 136whp with exhaust,(higher because i think he has lsd and a newer car). now a 89-90 has 15hp less, so a 89-90 stock would probably have a little over 100whp.
now,
"Port and polished, bored 40 over, 7300RPM, Non stock cam (found that receipt today)" [plus more fuel delivery as he stated]
those mods gave him almost 60whp? :faint:

Silly americans and their online calculators. those things give a rough estimate at best NOT factoring in track conditions driver skill etc etc..

[logo20]

i know those calculator are not 100% accurate, but there are pretty close to it. another thing to notice is,
"It is a high revver. (7300RPM, 40MPH, 69MPH, 94MPH 1st, second, third))"
our cars have the same gears, so if my car in first gear(with a few mods) at 7000rpm does not even 30mph his does 40?
:confused:

[Bill Roberts]

Geeeze dude, I feel for you topping at at only 30MPH in 1st. I just now went out and snapped this picture, took it up to 30 in first, snapped the picture.

http://groups.msn.com/AudioDiscussionProductiontoAudiophile/screenshots.msnw?action=ShowPhoto&PhotoID=37



Anyone else want to take their car up to 30 in first and snap a picture? You should at least get between 36 and 38 at 7K.

Maybe I have some goodies that others don't have, perhaps like a taller gear I don't know about??

How about it guys, Only takes 5 mins to see.

30.5 MPH=5800RPM

[logo20]

well if it is true that you were in 1st gear when you took that picture then you must have a higher gear, maybe even lsd? that would make your 14.8 more believable.
I'm not trying to flame, just discussing, I am consider to rebuild my engine head myself.

[Bill Roberts]

The head is the key to cheap power. you must be very careful if you have it shaved. You have to make darn sure your compression does not go up too high and that you have clearance for the valves to open. It gets very tight in there. Nothing like haveing your head shaved and then turning the engine over by hand and have the pistons touching the valves. Makes a huge mess.

Also, Port and polish. If you read the scca rules, they don't seem to allow it in some catigories. Why? Tremedous advantage.


Here is an excerpt:

"Engines may be rebored to the manufacturer's first standard overbore, not to exceed 0.020". Sleeving is allowed to repair to the standard bore. Only OEM-type standard or first overbore pistons of the same configuration and of the same or greater weights are permitted. No interchange between cast and forged pistons is allowed.
Rotating and reciprocating parts may not be balanced.
Port matching is not allowed."


That totally counts me out.


IF you can find a machine shop that has a true head person there that is 20 years+ experience in reshaping the bowls behind the valves, reshaping the combustion chamber, CCing the heads for perfect balance of size in each combustion chamber and matching valves, large increases of horsepower can be achieved.

It is worth looking into getting serious work done to the heads since we know the bottom end is happy with compression around 185PSI.

I am very surprised about your gear ratio.

I do have a 5 speed Manual, that may have not been mentioned. 5 speed, SE with the performance package. 1989 May of 1989 (I understand their were Four different types of 89 fastbacks. Early and late, with SE Performance package. With Lighting and convience package.


I personally would like for others to post some pictures of their tach at 30MPH. We are here to learn about our cars and get the most of them..
BTW, The K&N filter is a sleeper mod. Worth the 45 bucks for sure. I would dare to say I picked up at least 5 horses, they claim up to 10% more horsepower.

[Steeles]

I dont have my cam with me but I'll see what mine is later this afternoon. but mines gonna be weird anyway I've got a 4.36 gear in mine

[adey]

Originally posted by logo20
well if it is true that you were in 1st gear when you took that picture then you must have a higher gear, maybe even lsd? An LSD will do nothing for your top speed at any given RPM in any given gear; it's the FINAL DRIVE (ring gear that's bolted on to the diff) and GEARING of the transmission that makes a difference. :rolleyes:

edit: I forgot to include that over all wheel and tire diameter will also affect top speed in a given gear.

[logo20]

I know I said it myself, but the lsd put more power to the wheels making he's car faster [that would make your 14.8 more believable]
smaller tire diameter will make the speedometer to read faster than you actually going but the difference is minimum, here a calculator (http://www.miata.net/garage/tirecalc.html)

[Bill Roberts]

The relationship of the tach to the speedometer is locked due to the gear ratio of transmission/differential. Tire size does not matter on their relationship together. It is the same if you jack the rear of the car up, tire size would be irrelavent.

On the other hand, tire size does have a direct relationship to the speed of travel and acts as a "gear" itself. The incorrect size tires would give a false speedo reading pertaining to the actualy traveled speed and distance but the tach at 5800 for 30.5MPH on the speedo would never change even if I put mud grips on the car. The speed traveled however would be changed.

I use BF Goodrich 205 60 15's all the way around. This is the stock tire for the jj factory 6.5 inch alloy wheels.

My speedo error is less than 0.5%

[s0ldats]

Originally posted by logo20
I know I said it myself, but the lsd put more power to the wheels making he's car faster [that would make your 14.8 more believable]
smaller tire diameter will make the speedometer to read faster than you actually going but the difference is minimum, here a calculator (http://www.miata.net/garage/tirecalc.html)

the calculator can't save you... please ...bill knows his sh1t... he's still finding receipts for his car...who knows what else was done.



edit: also yeah, the tire size will be a factor in the actual speed your car is traveling, but it won't change the reading of the speedo or tach.

[sykikchimp]

Aren't the Rev's counted by the ECU?, and speed counted by a gear?

I am at work, so no access to teh FSM.. where is the Rev meter attached?

Unless the RPM, and Speed where gathered by the same sensor, or at least from the same mechanism/location, that relationship will change by changing Final drive ratio/tire size..

For instance, the revs are counted at the crank, by the CAS, and the speed is detected at the back of the tranny (rotational speed of the driveshaft) There won't always be the same. I mean, I sure would hope that my rpms are a bit higher after installing a 4.3 gear (vs. the stock 4.08) at the same speed..

edit.. OK, I'm sure your wrong here Bill.. If the Speed, and RPM where locked, then that would mean they are a function of each other, stored in the ECU. If this was so, then there would be no need for a Speed sensor b/c the car could read speed based on Gear selected vs. RPM.

edit2 - They do store such a function.. It is used to manage the Speed Limiter funtion of the car. BUT, the speedometer actually show speed from the speed sensor that is not directly related to the function. Thats why some people think they are doing 120 when the speed limiters fuel cut kicks in, and some people think they are doing 115, etc... It's really at 112.

[sykikchimp]

on a side note.. I do believe it is possible. I have seen several very high output SOHC race engines. Most with 250+ Whp. The SOHC engine is easier to tune in NA form. Most are running ITB's, and are required to idle at 2K+ rpm to stay running.

I can see why Logo is skeptical b/c I don't think I've seen or heard of more than 2 street driven NA 240's run under 15sec quarters.

Bill, I would like to know more about why you think you have larger injectors. It would require an alternate ecu or fuel controller (ala SAFC, etc), or modified MAF.. (i believe you said you may have some non standard MAF?) do you have any idea how your car is handling the addtional fuel capacity?

I would REALLY like to see a dyno on this car.

[Bill Roberts]

Changing your differential should throw your speedo off. (accuracy) If the car is jacked up off the ground, you would have the same relationship of crankshaft to driveshaft ratio. Putting a different rear end or changing the rear tires is not going to change the ratio of crankshaft RPM to Driveshaft RPM. All you are doing is changing how fast the car goes down the road and in relationship with revs, not changing the speedo to tach relationship.

The speed sensor measures the driveshaft RPM. The Tach measures the crankshaft RPM. The transmission alone determines that relationship.

The only other thing that could change that relationship would be a faulty speedometer head and sensor or a slipping clutch. It is as locked, as the clutches' ability to grab and stay engauged. With an automatic (fluid coupled) some slippage will register since because of the touque converter, you can idle in gear.

The only other way the tach to speedo relationship (again not the actual speed of the car) would change is if the sensor for speed was located on the rear axle. To my understanding, it is located in the transmission.

[MorganS13]

heres what i came up with, ~29mph at 5870 rpm, 93 DOHC 5-speed.. could be speedo error or gearing, i don't really know.

[Bill Roberts]

That is very close. At least it is not 7000RPM for 30MPH.

Speedos can be off some I am sure. But regardless of the rear end or tires, it should always read the same unless the transmission gears or the sensor is changed...will not mean you are actually going 29MPH but it will read it.

Think about it, take your driveshaft out of the car and run it up through the gears. This is why that relationship shall be of locked nature. It is the tranny gears that determine that.

My whole therory is blown if the sensor is meauring the revs AFTER the differential though...like on one of the half shafts. They wold not do that because it would throw it way off on a turn.


I appreciate you verifying that. Not everyone is willing to wind their car up under practically no load in first. The speedo numbers are laid out differently on different dials as well.

[sykikchimp]

no.. doh.. you are correct. The Speed sensor IS in teh transmission, and therefore changing final gear ratios shouldn't affect that speed-rpm ratio.

:hammer: <--for me.. :bowdown: <--for u

I was right when I said this:
I mean, I sure would hope that my rpms are a bit higher after installing a 4.3 gear (vs. the stock 4.08) at the same speed..
the rpms would be higher for the same speed, but the measured speed by the speedometer would be off. So that relationship would still exsist. ..errr.. no idea why I didn't see that before.

[sykikchimp]

interesting enough, if you calculate out what the RPM of the car should be at 30 mph given a 3.321 transmission gear, and a 4.08 final drive gear, and 205/60 tires.. RPM = 6887.. no where near what you guys show in your pictures.. I wonder why that is???

[AceInHole]

if anyone has seen my 0 to 60 run (http://pj.240sxone.com/albums/album04/0to60.avi) you'll notice that at the end of 1st gear I'm doing just under 35.... at 6500 RPM.
http://pj.240sxone.com/albums/album04/IMG_5503.jpg


FWIW: I've been in an SOHC with just a cam, and that thing surprised the hell out of me. As for the port and polish, the SOHC can see very large gains from it. By nature of its design in stock form, compared to the DOHC it's restrictive. Even my newbie DIY port and polish made a difference that was noticeable (although, the difference may have been amplified some by the turbo).

Bill: according to the SCCA rules you posted, we'd be allowed to do a lot of head work as long as the port openings are kept the same size as stock :p

[sykikchimp]

Originally posted by sykikchimp
interesting enough, if you calculate out what the RPM of the car should be at 30 mph given a 3.321 transmission gear, and a 4.08 final drive gear, and 205/60 tires.. RPM = 6887.. no where near what you guys show in your pictures.. I wonder why that is???

Ok, I think my calc is wrong.. Does anyone know the Primary drive ratio of the engine? as in, if the crank turns one revolution, does the shaft that connects to the transmission gears spin one revolution? so that the actual drive shaft spins 3.321 times per 1 crank revolution in 1st gear? Or is there another gear b/w the transmissions gear and the flywheel?

EDIT - Or.. what am I missing in this calculation:
total rotations of a 205/60-15 tire in 1 mile: 1016.7
1016.7 x 4.08 (final drive ratio) x 3.321(gear ratio) = 13775.9 Revolutions in one mile.
since 30mph = 1/2 mile in 1 min.. multiple 13775.9 x .5 = 6887

Is there a primary drive ratio I'm missing???


p.s . I edit way too much./

[Bill Roberts]

Your speedo to tach seems on par with mine. Nice second gear :)

[Bill Roberts]

If you have a transmission laying around, put it in first and turn the front shaft and see how many turns the front shaft turns for one turn of the back shaft. That will be your true first gear ratio for the tranny. Then you have to figure that gear (differential)....this is when the tires make the real difference in actual speed. Take the diameter of the tire X 3.1415926 (distance /revolution) and look at your numbers from that angle. This is not taking the speedo in to account. Also remember, when the tire is turning fast, the contact patch (well real fast) will be smaller and the diameter slightly larger due to centrifical force. (You've seen the lift on the tires of the top fuel dragsters) Driving the vette at 170 feels like riding on ice skate blades.

Driving over 200 takes on a whole new meaning of life. (of course the 240 will not go past 115 on the clock...Mine won't...which is cool.)


As for final ratio, this should mean revs RPM to rear end axle turns only in 4th gear where the tranny is 1 to 1.

Perhaps the tranny spec already is taking the differential into the equasion...as in final ratio. It figures if you are turning 1.0 to 1.0 in 4th, I take that to mean the rear axel RPM matches the crankshaft RPM. This may be where your equasion is getting fouled up. Look into it.

Keep pumping that math...fun isn't it!

(Of course the crankshaft is 1 to 1) No gearing inside our engines (LOL)

[sykikchimp]

Originally posted by Bill Roberts
As for final ratio, this should mean revs RPM to rear end axle turns only in 4th gear where the tranny is 1 to 1.

Keep pumping that math...fun isn't it!

(Of course the crankshaft is 1 to 1) No gearing inside our engines (LOL)

Even if centrifugal force was acting on the tire at 30mph enough to cause a sever change, engine RPM wouldn't be 1000rpm below the gearing calculation..

I know there's no gear in the engine but what about the ratio of the gears here b/w the Green and red gears? That would be the primary ratio I'm missing?
http://static.howstuffworks.com/gif/trans1.gif

That gear ratio would have to be around ~.85. I wounder where I could find that actual ratio?

[Bill Roberts]

It looks like the ratios that are provided with the transmission gears are deemed "final ratios" which equate to the transmission with the differential.

So 4th is basically 1 to 1 meaning the rear axels are turning the same speed as the engine with the differental (stock) employed. Now changing the a$$ end will definitly disturb this final ratio.

I was looking at some car specs and on transmission ratios, it is referred to as "final ratio".

That will answer that....I hope.

[AceInHole]

Originally posted by Bill Roberts
Your speedo to tach seems on par with mine. Nice second gear :)
yeah.... although 1st and 2nd don't last too long.... :p

[sykikchimp]

Originally posted by Bill Roberts
It looks like the ratios that are provided with the transmission gears are deemed "final ratios" which equate to the transmission with the differential.

So 4th is basically 1 to 1 meaning the rear axels are turning the same speed as the engine with the differental (stock) employed. Now changing the a$$ end will definitly disturb this final ratio.

I was looking at some car specs and on transmission ratios, it is referred to as "final ratio".

That will answer that....I hope.

I was under the impression that the 1:1 gear ratio meant that the Driveshaft was spinning the same speed as the engine. The wheels would be spinning 4.08 times slower. But even if this is true, it still is fairly far off from what you guys are experiencing at 30mph..

[Bill Roberts]

Not trying to be a smarty, but do the math again. I suppose you have one of your sets of numbers in the algebra reversed.



Try again!

(this is meant to be fun, not just running up my post count)

Also, look at 69 in 2nd and 94 in third. I can get the whole enchalada in forth and 5th, It wants to rock on out...but the mean little government in the compu. says NO bitch!


Final drive ratio, RPM, tire diameter X 3.1415926




Oh...(edit) one little hint, my tire diameter is 24.2 inches. You will need to multiply that by 3.1415025 to determine distance per rev for 4th gear in inches. Consider all the varables.

I have confidence in ya! (really I do)


Just do 4th if all else fails.

[logo20]

here another calculator http://www.rmahc.com/speedcalculator.html
Bill is right, our cars can do 39 in 1st, 69 in 2nd and almost 100 in 3rd at 7300rpms, but we need a lot of top end power to do it.

:cool:

[Steeles]

well I tried to do the 35mph test this morning... with no luck Im at about 7200rpm but the car bucks and wont hold the speed (remember I have a 4.36 final gear in mine)

[sykikchimp]

I had the tire diameter wrong.

I said 205 *.60 = 4.8" +15 to get sidewall height. I forgot to DOUBLE the side wall hieght. ARRGG.. :bash: :hammer:

My calc should have been 2(8 x .60)+15 = 24.6

I always miss something small and stupid. I'm better at english than math.. :P

[Steeles]

Originally posted by sykikchimp
I had the tire diameter wrong.

I said 205 *.60 = 4.8" +15 to get sidewall height. I forgot to DOUBLE the side wall hieght. ARRGG.. :bash: :hammer:

My calc should have been 2(8 x .60)+15 = 24.6

I always miss something small and stupid. I'm better at english than math.. :P

then try and say that in english....... :D

[Phlip]

Originally posted by Steeles
then try and say that in english....... :D
I got this one.
Start with a 15 inch wheel
Factor in the fact that a 205 width tire is 8 inches
Aspect ratio (the 60) is a percentage of that width, 4.8 inches, and you will do that twice, for the top and bottom of the tire.
15+4.8+4.8=24.6


*TAKES A BOW*

[Phlip]

I really tried not to get involved in this thread, but since I have posted, I forget to notice how fast I'm going in first, but I know for fact that I take second to a hair under 60, third goes to 90something-ish, and I can take 4th and 5th to the top speed, which appears just past 120 on my car... 225/45-17 tires, but it did the same with the 195/60-15s too if I remember last year correctly, I think I drink too much.

[Steeles]

*kicks Phlip while he's bent over*

cool.. that makes a lil more sense.. well actually I just went back and reread WHY he was doing that math and it made more sense. going back to the 17s has definately made a difference in the feel of the car.. 225/45/17 vs 225/50/16 at least to me. of course I need an alignment too.

[Phlip]

Originally posted by Steeles
*kicks Phlip while he's bent over*

cool.. that makes a lil more sense.. well actually I just went back and reread WHY he was doing that math and it made more sense. going back to the 17s has definately made a difference in the feel of the car.. 225/45/17 vs 225/50/16 at least to me. of course I need an alignment too.
*shoots steeles in the head for kicking him*
Having your 17s back made a positive or negative effect? And you are always in need of an alignment, did you get it done when you guys put the hub in, or are you waiting for the rest of your stuff before you do that?

[Steeles]

*spits the bullet back at phlip*

yeah I got it aligned after the hub went in but its been off for some reason lately.. I think a pothole knocked it out. not by much but now with the spacers and wheels on its more pronounced. as for positive or negative... umm dunno.. cant really call it.. just one of those noticable differences. that and I've only really had her on the highway. no hard driving so cant really say.

[mvaters]

so how much power that got?

[Shift_Nissan]

oh that car is powered by full-race its making 539rwhp. its running a GT3040 turbo

[Annoying Eric]

Old news.......LOL.. you really brought this one back from the dead...

[mjjstang]

haha i tried dl it and it woulndt let me then I looked at the date, I guess its true dinosaurs cant come back to life.

[xVaporx]

vid can be found on full race's website

[ThatGuy]

Shift_Nissan, you brought a thread back from 2 years ago. Don't do this again. Pay closer attention next time.