View Full Version : Upgrading from Tomei 260's to 270's Solids
Master Chief
11-18-2009, 01:50 PM
Hi all.
I am planing of going to a Tomei Solid lifter cam Setup.
Curently i have 260's.
I have a GT3582 that comes on full boost at about 4900-5000, and power goes up, until about 7000-7200 RPM, before it starts to drop off.
Max torque 435lb/ft, and max power 530hp @ HUBS on Dynapack.
I am trying to decide wheter to go with 260's Solids, for the Solid lifter upgrade, or go for 270's.
I want to be able to make power beyond 7000-7200, but i dont want the turbo to come in later than it does now.
Does anyone have any experience with upgrading from 260's to 270's, and can comment on the difference ?
Better yet, if someone knows of a dyno comperation or something...
Thanks,
Dany.
Master Chief
11-19-2009, 10:44 AM
No one with some info on the subject - really need some help...
jspaeth
11-19-2009, 10:56 AM
No one with some info on the subject - really need some help...
I don't have any real experience with this, but my feeling is that the cams are not what is causing the spool to be as late as it is.
Changing from 260's--->270's shouldn't make it spool later I don't think.....but they should help it breathe better up top.
Plus, if it is already taking that long to spool, you might as well throw a greddy intake manifold on there and help it breathe out to much higher RPMS.
With that massive of a turbo, you should build a 9K solid head with some big cams and a Greddy Intake Mani so you can really keep making power out past 8K
Master Chief
11-19-2009, 01:44 PM
The engine is fully built, and as said already made 530hp.
I do have a Greddy Intake BTW.
The spool is late, cuz the turbo is big - i can live with it as it is now - i am just concerned of it getting even later with Longer duration cams.
As for a solid head - thats exactly why iam asking, as i am building a solid head now - i just need to decide on the cams to use.
I had 260's hydraulic cams until now - and i want to know what to expect with 270's Solids.
Thanks.
S13 curtis
11-19-2009, 04:34 PM
it waill spool it faster as it its moveing more air threw the motor with bigger cams, your power band will be good up top.
juggernaut1
11-19-2009, 05:16 PM
I don't have any direct experience with the differences with those cams but bigger duration cams will make it spool later - thats what they do - they shift your boost, torque and power further up the rpm band.
BTW I run the 260 procams hla's and make peak hp at 7700rpm with a FR twinscroll 3071 and Hypertune plenum. I do have headwork though and run bigger ex valves. This setup also makes 24psi by 4000 rpm by retaining the VCT.
jspaeth
11-19-2009, 05:23 PM
I don't have any direct experience with the differences with those cams but bigger duration cams will make it spool later - thats what they do - they shift your boost, torque and power further up the rpm band.
BTW I run the 260 procams hla's and make peak hp at 7700rpm with a FR twinscroll 3071 and Hypertune plenum. I do have headwork though and run bigger ex valves. This setup also makes 24psi by 4000 rpm by retaining the VCT.
In general I agree with you, but the power is already coming on so late, that I don't think 270s will make it come on later.
If you had a little turbo that made peak tq. by 3500 RPM, then I would agree that the big cams would make it laggier.
I just don't see 270s making this setup even laggier.
juggernaut1
11-19-2009, 05:38 PM
For his sake I hope bigger cams don't make it laggier - but I'm just trying to understand the theory how bigger duration cams wouldn't make it laggier irrespective of the turbo.
Although he could use adjustable cam gears to tailor the rpm band of the power curve to some extent which would be dictated by the purpose of the car which we don't know.
jspaeth
11-19-2009, 05:42 PM
I will hold off on arguing or insisting I am right, but maybe someone who really knows the answer will chime in.
My intuition says it won't hurt spool up at all.
brndck
11-20-2009, 05:38 AM
i vote nos kit to help the turbo spool. sounds like this car is built for drag anyways.
Master Chief
11-20-2009, 11:41 AM
juggernaut - what power are you making ? It sounds you have a very wide power band - 24PSI by 4000 sounds great, but what is hapening up top ?
The current setup of the car, serves me well in ocasionaly drives around town, Drag, track days etc..... With my older GT3071, i used to drift it too, but i kind of lost interest in that, for now.
Because loosing rockers a couple of times, i decided to go with a solid lifter conversion - and as i need to get new cams for this, i am trying to decide between the 260's and 270's, meany to get a bit more performance as well as reliability at the same time.
As for the boost comming on at 5000, its not that bad when you in the right gear...
I just woudnt want it to be later, as i am not planing to go past 8000-8500 RPM anyway.
Soo - does anyone have Tomei 270's on there car, and can coment on the behaviour of the engine - i.e. Idle, boost coming on, power up top, etc.
A dyno would be great.
Here is mine, at 25-26 PSI.
http://img6.imageshack.us/img6/3383/dyno353360.jpg
Here is a link to some more info on the setup.
http://www.sxoc.com/vbb/showthread.php?t=427381
juggernaut1
11-21-2009, 05:21 PM
These are the only dyno's I have re the tune which as you can see were done a while ago. The tune was never completely finished because my tuner was borrowing a dyno on the day and ran out of dyno time. Also need to fix up the boost drop in the top end. Note the ambient temp was around 36 degrees when these were done. I have had it on another dyno since in cooler conditions and it made a couple of more psi across the board at the same rpm - for instance it was making 26 psi by 4000rpm - no printout to show unfortunately.
This dyno done in 4th gear - (5th is 1:1 in my car as I have a 6 speed close ratio Nismo box).....also shows 24psi by around 4000rpm even in 4th....5th gear (1:1) is better still.
http://i241.photobucket.com/albums/ff132/juggernaut000/Dyno1-1.jpg
Same dyno as above overlaid onto a different s15 with single scroll 3071 ex gate on 6boost manifold 256/256 poncams and stock intake.
http://i241.photobucket.com/albums/ff132/juggernaut000/Dyno2.jpg
This dyno done in 5th gear (1:1) after retarding the ex cam a couple of degrees - picked up more low and mid and lost top end - revved to 8,000rpm although shown in klm/h. Notice how it holds up power reasonably well at this rpm even with the 260 hla's......in any case the power nosing over is more likely attributable to the boost dropping as show in the dyno. Boost curve in general is a little rough
I know the scaling is crap on the horizontal line. One day I will get a better printout.
http://i241.photobucket.com/albums/ff132/juggernaut000/Dyno11.jpg
juggernaut1
11-21-2009, 06:20 PM
Master Chief
I read your other thread links to get some background on your setup....from my understanding you are using Tomei Type A springs in this setup....I also read where you through a rocker on the dyno spinning to 8,000.
IMO the springs are no good to turn to 8,000...as evidenced by you throwing a rocker........in fact I think even Tomei only recommends 7500 with these springs. I also have these springs but the springs were shimmed by about 3mm to bring up the spring pressure to spin it to 8000rpm with the 260 HLA's. So high pressure or shimmed up springs will allow you to rev it further to take full advantage of the GT35R without requiring the use of a bigger cam.
Also are you currently taking advantage of the VCT.....if you are and if you move up to the 260 or 270 solids you can kiss that goodby and you will suffer poorer low/mid response as the VCT does help somewhat to spool the turbo and give better low end response.....and no amount of adjusting cam gears will restore the advantage that the low/mid torque the VCT provides.
I also understand you are running a Tial housig on this turbo which is basically T25 in size at the inlet. This could also pose a restriction at higher rpm as it simply won't have the flow capabilities. I only mention this because if you put in 270 cams for high rpm and the ex housing is a restriction at those rpm you may have gone backwards in a sense.
Finally, I see you are using the Greddy plenum on the stock lower runners. The lower runners are still relatively long and will hurt top end torque. Greddy now makes a one piece intake with shorter runners for the blacktop motor which would help your top end but it will also hurt your low/midrange. The lower runners are also quite restrictive as I had my stock intake hand ported and extrude honed and picked up nearly 50 cfm per runner - the lower runners had posed the most restriction and this is where most of the flow gains were made. However, I can't specifically report on the effectiveness of this mod as I ended up fitting the Hypertune intake/plenum.
Anyway these are my thoughts and experiences.
Cheers
fliprayzin240sx
11-21-2009, 06:51 PM
I got 270s with Solids but I cant really give you much input. The shitty thing is we have no working dyno on island...cams right now are not dialed in. Full boost at 5k, starts spooling by 4k, redline and tuned up to 9k but I set my redline down to 8k daily and auto-x/HPDEs. Boost is set at 1.4 and 1.8, I'm too pussified to push it to 1.8bar.
Teambadrun
11-22-2009, 12:25 AM
I run 260 Degree Tomei Solids
Friends Racing S15 runs 2.2KG/CM2 boost ( 32psi boost) and that is a TD06H-25G 10cm same as mine with NOS
that makes 662ps.........
I dont see why you would want 270 deg cams ... Maybe if it was purely a drag car????????????????
Our's are drift machines.
Master Chief
11-22-2009, 05:07 PM
I hear you guys, and really appritiate the time you take to help me out.
I dissagree on the TIAL housing having a "t25" like sized inlet, beeing a restriction.
The inlet of the turbo housing, has no affect on flow - only the turbine A/R does.
If the inlet of the turbine is large enough to accomodate the turbine A/R - there is no restriction.
All turbo housing are constructed to have an equal or larger inlet then the maximum cross section area of the turbo housing. An area wich actualy dictaes the turbo A/R.
Fliprazin - what turbo do you have ? what A/R ?
I will be using SUPERTECH double springs with this setup, and defenetly want to go with the solid lifter setup.
I'll have to make up my mind between the 260 or 270.
If someone has more opinions, i'll be glad to hear them.
Thanks.
juggernaut1
11-23-2009, 03:19 AM
I dissagree on the TIAL housing having a "t25" like sized inlet, beeing a restriction.
The inlet of the turbo housing, has no affect on flow - only the turbine A/R does.
If the inlet of the turbine is large enough to accomodate the turbine A/R - there is no restriction.
All turbo housing are constructed to have an equal or larger inlet then the maximum cross section area of the turbo housing. An area wich actualy dictaes the turbo A/R.
I hear what your saying - but I don't see Garrett or any other turbo manufacturer using t25 inlet size on this size turbo. They are usually T3 and now I see T4 housings are available through ATP for the GT35.
Not a disagreement but just an observation.
Also have you considered staggering your cams i.e. 260 inlet and 270 exhaust is popular.
Master Chief
11-23-2009, 05:41 PM
HKS for example use T25 inlet flanges on all but their "PRO" series turbos - including GT35 variations.
Also the Tial housing's flange is larger then a T25 - if speaking from flange area point of view.
I havent considered staggering them - i never really took the time to try to understand the benefith in that.
How would that help me ?
s15specR
11-23-2009, 05:53 PM
How would that help me ?
I'm interested in this explanation as well.
fliprayzin240sx
11-23-2009, 07:55 PM
I hear you guys, and really appritiate the time you take to help me out.
I dissagree on the TIAL housing having a "t25" like sized inlet, beeing a restriction.
The inlet of the turbo housing, has no affect on flow - only the turbine A/R does.
If the inlet of the turbine is large enough to accomodate the turbine A/R - there is no restriction.
All turbo housing are constructed to have an equal or larger inlet then the maximum cross section area of the turbo housing. An area wich actualy dictaes the turbo A/R.
Fliprazin - what turbo do you have ? what A/R ?
I will be using SUPERTECH double springs with this setup, and defenetly want to go with the solid lifter setup.
I'll have to make up my mind between the 260 or 270.
If someone has more opinions, i'll be glad to hear them.
Thanks.
Running the same turbo as you...GT3582R. Fully spooled at 5k with 270s on both intake and exhaust side. Why dont you try to run 260 on the intake side and 270 on the exhaust side?
juggernaut1
11-23-2009, 08:49 PM
HKS for example use T25 inlet flanges on all but their "PRO" series turbos - including GT35 variations.
Also the Tial housing's flange is larger then a T25 - if speaking from flange area point of view.
I havent considered staggering them - i never really took the time to try to understand the benefith in that.
How would that help me ?
Yes, you are right HKS use the T25 size on their 3040 (similar to GT35) and its a laggy thing. All their other turbos are smaller sized which is better suited to the T25 flange size. Having said that even a pair of HKS 2835 twins on an RB26 is slower to spool and makes less power than a GT35 with a T4 1.06 open housing.
I've had a T25 Tial flange housing and based on my calcs the opening is no bigger than a T25 Garrett from an area point of view.
Back on topic .....you gain response with the staggered setup - 256/264 HKS and Greddy Easy Cams for instance are common as well as 264/272 HKS staggered setups.
A few people in OZ initially used the Tomies 270/270 then swapped the inlet back to a 260 and noted an improvement in response for street/circuit duties. Also Camtech cams make a 255/260 combo and with a T3 .63 3071 20 psi is reached by around 3600rpm on an unbuilt SR20.
I think the smaller intake improves the spool which in turn leads to better cylinder filling and therefore torque/power at lower/mid rpm as evidence by numerous dyno's.
Master Chief
11-24-2009, 02:43 PM
If i think about it a bit, the difrence between a 260/270 setup, to 270/270 one, would be the OVERLAP time.
260/270 would overlap less, wich i guess is what would help with response.
Interesting though.... I will research this further.
Tanks.
Teambadrun
12-29-2009, 09:00 PM
These are the only dyno's I have re the tune which as you can see were done a while ago. The tune was never completely finished because my tuner was borrowing a dyno on the day and ran out of dyno time. Also need to fix up the boost drop in the top end. Note the ambient temp was around 36 degrees when these were done. I have had it on another dyno since in cooler conditions and it made a couple of more psi across the board at the same rpm - for instance it was making 26 psi by 4000rpm - no printout to show unfortunately.
This dyno done in 4th gear - (5th is 1:1 in my car as I have a 6 speed close ratio Nismo box).....also shows 24psi by around 4000rpm even in 4th....5th gear (1:1) is better still.
http://i241.photobucket.com/albums/ff132/juggernaut000/Dyno1-1.jpg
Same dyno as above overlaid onto a different s15 with single scroll 3071 ex gate on 6boost manifold 256/256 poncams and stock intake.
http://i241.photobucket.com/albums/ff132/juggernaut000/Dyno2.jpg
This dyno done in 5th gear (1:1) after retarding the ex cam a couple of degrees - picked up more low and mid and lost top end - revved to 8,000rpm although shown in klm/h. Notice how it holds up power reasonably well at this rpm even with the 260 hla's......in any case the power nosing over is more likely attributable to the boost dropping as show in the dyno. Boost curve in general is a little rough
I know the scaling is crap on the horizontal line. One day I will get a better printout.
http://i241.photobucket.com/albums/ff132/juggernaut000/Dyno11.jpg
That setup seems quite laggy too, you are making sweet fuck all power at 4000rpm and you claim thats full boost.. Who cares what "BOOST" you are making at LOW rpm it's about POWER @ low RPM...
Israel guy, you shouldn't worry about 270DEG cam's unless its purely drag.
Friends racing S15,( also myself) run a TD06H-25G 10cm and we make bucket loads of downlow POWER and super early boost... 260,260 12.0mm solid lifters.
HLA are really really really shit and you should definately just get 12mm 260 camshafts. Cam gear adjustment will depend on your setup, with big big turbos it might help you downlow by 20rwkw(30rwhp or so) but you will sacrifice topend.
Geno750
12-29-2009, 10:04 PM
Given that you're using a 35R, and with the rev advantages solids would give you, I'd go with 270's. They would better match that turbo than 260's would.
Monooxide
12-30-2009, 02:20 PM
There is a lot of good talk going on in this thread however I don't feel the question of the 260 vs. 270 cams was answered.
The 270 duration cams will cause the turbo to achieve full boost later. The reason this as juggernaut has touched on is that this shifts the peak volumetric efficiency of your engine more towards redline. Even the Greddy intake manifold with larger(diameter) and shorter runners shifts this peak VE further towards redline. However pushing this peak VE higher in the RPM range causes your peak torque to appear later and give you more peak HP.
I noticed in your post with the dyno graph you're saying power is falling off, this is not true. Your torque is falling off but since it is falling off at a slow rate you're still gaining power. Which is the ability to do work. I personally don't think you need anymore cam. The 270s will of course raise this peak HP number because it is giving you more torque up top so...for the sake of it let's say the 270 cams shift your powerband 500 RPM. You would make... 554.3 WHP which is a gain of 21 WHP. This is found by the equation below:
(Torque*RPM)/5252 = HP
I converted the kg/m by multiplying by 2.2 pounds and 3.281 feet...not 100% accurate but close enough.
Anyhow, this shift in power means you're going to lose power in the low-end too. Everything has its trade-offs. If you're wanting a little more response out of your car you can get rid of the Greddy intake manifold and return to the stock intake manifold, this will give you better spool up but unfortunately less top end.
Master Chief
12-30-2009, 03:34 PM
I said power, i was refering to torque - sorry.
I just think of an engine as making torque, not HP, so when i say power, i reffered to the torque.
I belive the 270's will not only shift the power a few 100ed RPM up, bit it will also lower the decent rate of the torque line.
My aim is basicly, to have the torque drop rate, be smaller.....I.E. A streighter torque line, wich will result in more HP acrross the band.
If i wasnt going to SOLIDS, i wouldnt replace my 260's, but since i need new cams anyway, i am exploring the possibility.
Anyway, i'll try the 270/270, and if i dont like it, i'll try a 260/270, and if i still dont like it, i'll try 260/260...... by thay time, someone will have a chance to purches a hardly used set of solid cams...... :)
steve shadows
12-30-2009, 05:34 PM
I would stick with 260s if you like where your torque and power band is coming on now.
You will probably raise your top end power up slightly with the 270s but will also shift the power band over to the right slightly I have seen this with almost every cam change up from 260 or 264 to a 270 or 272 the torque band will just shift over to the right more, usually 500 rpms or so.
I suggest you stick with 260 cams or possibly go with 264 HKS solid compatible camshafts for even more mid-range.
The SR motor likes to make it's peak torque and power in the mid-range and upper mid-range between 5500-6800 rpms. It is not a high rpm motor when using a factory head. The VE heads are much more oriented around high rpm power between 7000-9000 rpms with higher duration cams and larger turbos,some even capable or 10500 on street setups.
I suggest working with the motor the way the motor wants to make power and complimenting this for the best and more smooth and violent power band. Every tuner has different experiences and philosophies though.
Another thing you could do is stick to a smaller plenum with longer runners or stock Intake Manifold design as a compromise to the higher duration cams. This is something that actually works even better for having your cake and eating it too. I am a big proponent of long runner, small plenum IM on SR for a torquey and broader low end range of power
Monooxide
12-30-2009, 05:45 PM
I would stick with 260s if you like where your torque and power band is coming on now....
This is exactly what I said. I'd like to swing by your shop sometime but If I remember right, you're in Cali or something.
Master Chief
12-30-2009, 06:03 PM
Steeve - you say : "I suggest you stick with 260 cams or possibly go with 264 HKS solid compatible camshafts for even more mid-range. "
Why would 264 give me mor mid range, and 270's wont ?
Also, i dont really understand - what is the theory about using smaller/bigger pleanums and low end torque on a turbo engine ?
About the Cams - if everything shifts up 500RPM, but i still make power, up top, then it wont be so bad i guess - providing i can rev 500RPM higher, then i do today.
Anyway, any dyno numbers, on the torque/power difrence, of 260 and 270 cams, on the same engine/turbo etc. ???
Monooxide
12-30-2009, 07:36 PM
Steeve - you say : "I suggest you stick with 260 cams or possibly go with 264 HKS solid compatible camshafts for even more mid-range. "
Why would 264 give me mor mid range, and 270's wont ?
Also, i dont really understand - what is the theory about using smaller/bigger pleanums and low end torque on a turbo engine ?
About the Cams - if everything shifts up 500RPM, but i still make power, up top, then it wont be so bad i guess - providing i can rev 500RPM higher, then i do today.
Anyway, any dyno numbers, on the torque/power difrence, of 260 and 270 cams, on the same engine/turbo etc. ???
The different duration cams cause the valves to open and close at different times in relation to the stock cams which causes the engine to act differently as far as volumetric efficiency goes. The change in how the valves open/close causes a different resonance to occur in the intake manifold. This causes the engine to be more efficient in a different RPM range because this resonance lines up at a different time than the lower duaration cam and this happens to be later in RPM. Also the diameter and length of an intake manifold runner plays a role on how fast or slow the resonant wave travels through the runner which also decides when the resonant wave will be in "time" with the valve opening.
The stock cams and intake manifold reach their peak torque near 4000 RPM, this is because the length and diameter of the runner accompanied by the stock cams timing of the closing and opening events give a resonance to achieve this.
The higher the duration, shorter the runner and larger the diameter of the runner, the further into the RPM range your peak torque(or VE) will occur. Also the opposite is true for the opposite of all those attributes. The 264s will allow slightly more top end with less loss of spool-up and mid-range.
If you shift your torque curve 500 RPM to the right you'll run into the same complaint you're talking about at 7300. The curve will be almost identical, just shifted to the right. So you'll have that same loss in torque.
Basically, intake manifold and camshaft duration decide where you're going to make power.
Master Chief
01-02-2010, 05:41 AM
Not quite sure what do you refer to when you say "resonance".
In any way, i knew that longer runer manifolds, are especialy good for NA engines, designed in such a way to cause a venturi effect, to speed up the air going into the cylinder.
I can see how that might help in going from VACCUM to BOOST transition.
But after that, building boost, this is not as neccesary, as the air speed is set by the pressure inside the manifold, and longer runners would just cause for more lag.
I dont see how longer runners can help, while your on boost.
Now, since it takes meaby half a second, to go from VACCUM to 1 or 2 PSI, when you floor it, i think runing longer runners, is wrong for a turbo setup, especialy a high boost setup, where the main problem is building boost after you lift off for a second (to change gear or whatever).
There is "Throttle response" and there is "Turbo treshhold" and "Turbo Lag".
Many confuse these in my opinion.
I am mainly concrend with the LAG bit.
Also not sure how a smalle pleanum can help.....The ideal pleanum for any setup, should be bigger or equal to half of the engine displacment.
Thats what i remeber anyway.
Also about shifting the power curve -U R right, it will be baisicly shaped the same, but hopefully - 500 RPM more to the right...that means the 383lbf would be at 7260 instead of 7260 - wich means 566hp, instead of 533.....that 33hp more, for 500RPM - not so bad.
Really hopping it will fall less now, as a higher duration will increase VE accross the board.
The only question is, wheter the TURBO, wont start choaking thing up.
I really hope that this setup has the 580-600hp @ 25PSI, in it.
Well see.
Monooxide
01-02-2010, 12:33 PM
Well, as I mentioned previously you can google the topic of intake manifold resonance. Basically the air entering the cylinder comes to a stop when the valve closes this wave will "pool" up on the valve and return the opposite way at the speed of sound and will reach the end of the runner and enter a nodal state( not going to explain this) and return back down the runner. Now, when the wave is just about to hit the valve and the valve opens your air will have a more powerful cylinder filling.
This applies for N/A and turbo. The longer runners will help with spool up because the RPM they resonate at is a lower RPM, this increases your VE more towards your low end making your engine use the thermal energy more efficiently and help spool the turbo. I wasn't stating that it would help up top, I was solely mentioning that it would help response but you'd lose top end.
Everything has its trade-offs. If you're wanting a little more response out of your car you can get rid of the Greddy intake manifold and return to the stock intake manifold, this will give you better spool up but unfortunately less top end.
You won't gain VE all across the board with higher duration cams, you're going to lose it down low and gain it up top. It's the nature of the beast.
S14_Kouki
01-02-2010, 03:59 PM
Toda makes a 304 get that :)
Master Chief
01-02-2010, 04:54 PM
I like and trust TOMEI, and i dont have a use for 304, with my turbo.
Moonoxide - meaby i didnt explain myself right, sying more VE across the board.
Check this out...
I took my dyno plost, and played a bit with the torque curve, to show you what i would like to see, more or less.
The blue line is the torque i got with the 260 HLA's, and the dark red, is the torque curve (more or brobably less) of what iam looking for.
I drew it like it is shifted to the right, but higher duration cams, would probably make for more torque , as well - so i drew it a bit higher.
Also i drew the DECLINE rate of it, as being smaller to the blue line..... basicly this is what iam aiming for - a streighter torqe curve.
I exagerated a bit probably, but this is just to explain my meaning.
http://www.max-tuning.com/gallery/mypics/wishfulldyno.jpg
Monooxide
01-02-2010, 07:07 PM
Ah, I see. Yea, doesn't seem like TOO lofty of a goal. With the Solid lifters maybe you should rev even higher and make ALOT of power.
juggernaut1
01-02-2010, 09:20 PM
That setup seems quite laggy too, you are making sweet fuck all power at 4000rpm and you claim thats full boost.. Who cares what "BOOST" you are making at LOW rpm it's about POWER @ low RPM...
Haha if i wanted power low in the rev i wouldnt be wasting my time with an sr.
Anyway mine makes around 180rwhp at 4000 which is as good as most 2871R's with similar cams and I have more top end.
I also ditched the stock intake and chose the Hypertune intake for a more linear power delivery rather than a more focused hit of torque in the mid-range. Plus it runs a full exhaust and legal cat which no doubt impacts on the overall power curve.
Master Chief
01-03-2010, 05:41 AM
Ah, I see. Yea, doesn't seem like TOO lofty of a goal. With the Solid lifters maybe you should rev even higher and make ALOT of power.
So you think my goal is realistic for the 270's ?
I really wouldnt like to rev more then i would need, to compensate for the later spool....
The big question is, wheter the Turbo housing, wont start choaking up top - well have to see about that.
Monooxide
01-03-2010, 11:51 AM
When I did the calculations without taking into account a better top end efficiency and solely a torque curve shift it was like 55* WHP with guestimated torque values from the curve.
I don't think the .82 A/R housing should give you any problems.
I was just suggesting more Revs because it would mean more power and longer use of it.
Master Chief
01-03-2010, 05:20 PM
Yes, i aggree about that - iam just concerned that higher revs, increase the chance of rockers flying/breaking etc...
To tell the truth - i'd be happy with reaching my goals, below 8000 RPM.
We'll see how it goes.
Thanks.
Teambadrun
01-10-2010, 08:58 PM
Haha if i wanted power low in the rev i wouldnt be wasting my time with an sr.
Anyway mine makes around 180rwhp at 4000 which is as good as most 2871R's with similar cams and I have more top end.
I also ditched the stock intake and chose the Hypertune intake for a more linear power delivery rather than a more focused hit of torque in the mid-range. Plus it runs a full exhaust and legal cat which no doubt impacts on the overall power curve.
SR makes shitloads of lowdown power man, i am making 225RWKW by 4000RPM and thats on pump 98... and NO NOS.. with nos its nearly 300rwkw hahhaa but thats upto you really.. each to there own. I dont think you should have low power for circuit, look at japan.. everyone has 600PS or over!
Circuit car = power!
juggernaut1
01-11-2010, 12:05 AM
Lol...mine is a street car not a racecar.
fliprayzin240sx
01-11-2010, 05:58 AM
Well, Frank from GarageBozo has been out here in Okinawa with Ross Petty, been talking to him about the car and he said that if you want response, throw away the 272s. Its purely for making top end power but makes the GT3582R superlaggy. If you're running a stroker kit, it might be worth it. If still running a stock 86mm or even 87mm bore, 272s will still hurt the setup if you want it to be more responsive. He said 264s for sure.
He's gonna play around with my setting and tune the next couple of days, I dont think I'll get ahold of 260s to swap out my 272s. He said he can tune it and try to get as much response on it, but 260s will be my best bet if I want the car to be more responsive for drifting/gymkhana/auto-x.
Master Chief
01-12-2010, 05:41 PM
Let us know how it went - i am curious to meaby see some dynoplots.
Jake1992
09-12-2013, 06:52 PM
are there any results of this anyone ? sorry for brining an old thread back alive!
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