60 ft times suck! what do i do to fix that [Archive] - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

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sil80forme

08-20-2005, 11:14 PM

ok i am running a stock ka w/ t3/t4, took to the track and laid down some horrible numbers, first because clutch MC went bad, and 60ft time was rediculously horrible, now i tried to drop the clutch at 2k and it bogged at start, so i dropped the clutch at 3k and spun allthe way through first gear, then decided to launch at 2500, and got the bog again. sooo what do i gotta doo to get good 60ft times? now that i fixed the clutch problem i gotta work on the 60ft times and thas what i am worried about when i go again this thurs.

massscene

08-21-2005, 05:46 PM

What kinda 60 ft times are we talkin about here?
Your first mistake is just droppin the clutch. Hold the revs at desired rpm. Then let clutch out untill right before the point the car wants to roll forward (preload). then at the right time slide the clutch from there. What kinda clutch you got?

sil80forme

08-21-2005, 08:38 PM

clutchmaster dual friction! i am lost on what u are talking about! i mean i dont even know what rpms i should be reving at, um i lostmy slip soo i cant check 60 ft times but i know they were pretty bad, thanx for ur help

Kenrik

08-21-2005, 11:11 PM

I have actually never taken my car to the track... is there a database of tracks for the country? anyone know of a good one in the Miami/Fort Lauderdale area? anyway... I know what he's talking about with the preload you need to have the clutch at the point just before it actually kicks in while you are reving... then just let it off and... I have been working on my launches from stoplights for the past year or so... I always smoke all the other cars... then again they are not trying to race me HAHA by the next red light all the drivers are always looking over at me like.. WTF (except a few civics from time to time..but I have yet to find one that can keep up..) Completely off topic... Why is it that civics always have Carbon buildup around the exhaust?? do Civic owners not know about MAINTENCE> ? I don't see other hondas or acuras with it.. just the crappy lil Civic Ricers

Kenrik

08-21-2005, 11:22 PM

Also.. what RPM to Rev at depends on your tires etc... I personally can launch from 3000rpm with minimal sliping on normal roads... I have big wide ass snow tires with tons of grip on them because the car used to live up north... I say try 2700-2800 you should be shifting at about 5500-6000 rpm (depending on cams etc.. (it could be higher) don't shift into every gear.. I usually go from 1st to 3rd to 4th... you will be almost done with your 1/4th by the time you hit 5th.. Remember I have never been to a track this is all from normal roads..

sil80forme

08-22-2005, 08:11 PM

u can actually skip2nd gear? i never heard of such a thing, iwouldnt think that this would work to well, like u would experience a great bog! but i will try it if u say soo. well i guess when i go on thursday that i will try as many options as possible. thanx for ur advice. oh yeah i was misstaken when i stated what clutch i am using it centerforce dual friction thanx again

Kenrik

08-22-2005, 10:37 PM

I can skip 2nd with my car without Bog... I don't know what kind of clutch I have since it was replaced before the car was mine.. 1st gets me upto 30mph 3rd gets me upto 55 4th to 75 5th anything after that... that's my shift pattern with my car/clutch it might be different for you... just keep in mind where your power bands are and always try to shift into your powerband (usually 3000-5500rpm on stock Cams (for a KA anyway) after 5500 you start to loose power... Keep in mind what gear you are in depends more on your MPH then anything... You will bog if you try to start out of 2nd gear (even though it can be done..) if you push first gear past where it is supposed to go you can shift into 3rd.. also try going from 1st to 2nd to 4th.. the less you have to shift the better.. Think of it this way.. you can drive at 45mph in 3rd 4th or 5th gears.. in 3rd gear your RPM will be high over 5k.. in 4th it will be about 3k and in 5th it will be 2k... you want to be in 4th at 45mph because it is just at the start of the powerband... 5th will bog till you get upto 75mph or so.. and 3rd will loose power over 5500... So go out and test different things on normal roads get your shift pattern down... so when you get to the track you can lay down some good numbers... Good luck!

One more thing... since you are running turbo and I am not your powerband should be shifted higher because of it.. figure out the "Sweet spot" for your car

019

08-23-2005, 08:15 AM

statik

08-23-2005, 09:22 AM

massscene

08-23-2005, 09:44 AM

whaaaat the eff are you talking about?.... who the hell skips a gear when theyre racing.....Exactly what I was thinking. Do not skip gears it is :bs: . I cant beleive there are people on here that actually believe that shit. I must say I love my car and all, and most people I have encountered since I traded my swapped civic in for a swapped 240 have been extremely helpful.... (thanks twins from nh) but I never heard something so stupid as what you just said about shifting gears when I was on the honda forums.

warriortch

08-23-2005, 10:54 AM

I think you just need to figure out how to launch the car... and when the light turns green you don't want to dump it, you want to slip it out as fast as you can without causing wheelspin (better tires, faster clutching). Be easy on the clutch after one pass.. don't try to hot lap the thing, give it a few minutes to cool down and go try it again. You should be shooting for a 2.1 - 2.2 60' time on normal street tires. you may also want to drop the tire pressure to around 15 psi. On my sr20 powered 240sx I get 2.2 consistently with 15 psi and some slipping of the clutch. You would rather spin a little than bog.

Jcb890

08-23-2005, 11:01 AM

holy shit kenrik is a fucking moron.

you grip better because you have snow tires? you smoke all the other cars that aren't racing you? you shift from 1st to 3rd while racing? holy shit dude. so its better to start a race at 35mph in 4th gear?

are you sure you're not mentally retarded kenrik? i'm being serious. there is no way you can actually believe that. i really hope you're kidding...

Jeff240sx

08-23-2005, 12:49 PM

The NEXT lash out at anyone on this forum will get that user banned. Jcb890, we had a discussion about the two direct insults. We do not tolerate that, no matter how dumb you think a statement was. Critique the statement, not the poster.

Next, skipping gears when I drive? Yes. I shift 1-4 or 1-2-5 when doing spirited runs from stoplights. In a race, however, skipping gears is only useful if you're putting down massive power. There is a reason most 6-8 second cars are running on 2 and 3 speed transmissions.

Launch rpm depends on the clutch, motor, method of engagement, suspension, tires, differential, temperature, and probably a dozen other variables. With slicks and a drivetrain that will handle it, on a prepped track and an sr20 no-torque downlow motor, you can drop for 6-7k and really scoot. But on street tires with my ka-t, on an unprepped track on a cold night, I'll slip from 2k. And then every other condition/combo in between. Usually, I end up doing a 3k slip with my z-rated tires on a hot, but unprepped track. Haven't made it on a night they prep the track for racing, but I think I'd try 5k slip or 3-3.5k dumps. You just have to experiment with it.
-Jeff

Kenrik

08-23-2005, 01:02 PM

I did say I was doing this from stop lights... thanks jeff240sx... that's what I was trying tto say it depends on your car what you can do that's why I told him to play with it. and Yes my wide (sold as Snow tires) tires with tons of tread DO help with wheel spin...

And yes when I said I smoke all the cars that are not racing me it was A JOKE!! I was being sarcastic..

Jcb890

08-23-2005, 01:18 PM

my bad dude, bad day at work. going from 1-3 or 2-4 is definately not gonna get you running as fast as possible.

however, snow tires with "more" tread aren't that great for traction. you want as big of a contact patch as possible and a soft compound so it sticks when warm and snow tires have a lot of grooves which is why they aren't as sticky as say slicks or drag radials or some Falkin Azenis, etc.

and jeff, does your track have weekend test and tunes? if so, they prep the track then, so go then and you'll be able to launch and hook on a VHT prepped track.

Jeff240sx

08-23-2005, 01:22 PM

Ya, Thursday/Saturday is VHT prepped, Friday is unprepped "legal street racing" night, where the tree is replaced by a traffic light. I seem to only be able to make it on Fridays :(
-Jeff

Jcb890

08-23-2005, 01:59 PM

Ya, Thursday/Saturday is VHT prepped, Friday is unprepped "legal street racing" night, where the tree is replaced by a traffic light. I seem to only be able to make it on Fridays :(
-Jeff

yeah, out here Sat and Sun are VHT prepped "Test and Tune" days so any car can go.

Monday and Weds nights are "Street Nights", there's still a tree but only "street" tires are allowed, which still means you can use ET Streets and Drag Radials since they're not considered slicks and there's some other rules to it.

statik

08-23-2005, 03:56 PM

The NEXT lash out at anyone on this forum will get that user banned. Jcb890, we had a discussion about the two direct insults. We do not tolerate that, no matter how dumb you think a statement was. Critique the statement, not the poster.

Next, skipping gears when I drive? Yes. I shift 1-4 or 1-2-5 when doing spirited runs from stoplights. In a race, however, skipping gears is only useful if you're putting down massive power. There is a reason most 6-8 second cars are running on 2 and 3 speed transmissions.

absolutely agree, but he says he doesnt have a turbo so im assuming this is either stock or a mild modded 240, there is no way you will run faster by skipping second gear. Also he said his 3rd went to 55, ive never seen a KA tranny top out 3rd at 55mph, my second topped out at 55 so i was very intrigued by his results...

sil80forme

08-23-2005, 06:16 PM

well then i see this topic got very heated up, well anyway thanx everyone for ur info. i am goin to the track on sat and will try some things to get better times, also i saw that someone mentioned falken azenis, would these be a good tire for drag? just curious cause i have always wanted a set and i need tires anyway

warriortch

08-23-2005, 08:27 PM

Falken Azenis do have a soft rubber compound, but a hard sidewall. They are perfect for drifting or road course stuff, but I used a set for drag racing and actually got better results with my Gforce Sport tires... drag tires have a nice soft sidewall to get that little wrinkle and added traction.

Jcb890

08-24-2005, 11:05 PM

slicks > drag radials
drag radials > street tires
azenis > snow tires