R33 Gtst For Drag Racing (suspension)

[MJTru]

I have asked about drag racing here in the past but would like to start a new thread. This time speaking about specific mods that can be done. Now that I have tried a few things. I would like to add that I personally dont own a gtst anymore and has opted to just own gtrs personally for those that may know me. Now I have built like 3 gtst rb25's blow up one of them and was left with 2 one of which I sold to a friend as well as importing a gtst which we installed the engine in. Its built for around 800hp and he has saved all his cash for five years and now the car is done for the last year. And with all the mods that I have learnt here ive been trying. To date we have been winning. Our compation is 2 2jz powered supras and like 2 evo3 and 1jz powered 240sx (180sx). His car is running 18psi and is capable of 25-30 psi with about a 100 shot of Nos maxing out at that.

So we have all the supporting mods. What I would like to talk about is suspension geometry and setup

First thing we did was down grade the rear btakes to oem stock 240sx rear disk. Next we ordered some american (Weld racing) rims and

M/T ET drag tires. Mounted them and it was a perfect fit. What ive noticed is that the car sits with a bit negative camber so the next thing we will work on is a set of toe and camber arms for the rear. We also installed a hicas lock bar. Im thinking about buying a set of pineapples for the rear end and upgrading the rear diff. To a 2 way unit. The car came from japan with lowering springs not coil overs so im stuck there until a new set is bought.

What we are really looking for is a set of front shocks or settings that will let the front rise up fast and be hard to drop. And the opposite in the rear (drop fast and lift up slow) I have yet to learn the right words for this meaning. Like rebound or somthing like that. I always mix it up. Lol. I what the rear to be like 365mm from the center of the wheel. Im thinking of using like a set of 1 to 2 kg springs. Im also thinking of taking off the sway bars to gain a bit more grip. I must get this right as there is a mustang with solid rear axle so as he launches his tires stay flat all the way through his weight transfer. His car isnt to fast but hooks like crazy. Hense why I like gtrs. I've personally beat him by like 7 cars. At 14 psi. Stock injectors and motor. But this gtst I have to learn to get it set up right. I feel as if I never completed my past goals before I got gtrs. And feel like I have a second chance to make it happen. The tricky part is that its not on a prep track. Its an old airport run way.

Am I on the right track here. Any help would really be appreciated guys. He beats the supra as well, we dont have a power issue we have a traction problem.

[hardsteppa]

with about a 100 shot of Nos maxing out at that

alright i'll say it...you're lucky that 100-shot of NOS didn't blow the welds on the intake.

but I know nothing about drag racing sorry, I prefer corners, all I know is in a street race, always launch on the count of 2.

[MJTru]

Lol. Funny I did bust a manifold once. Kml. But it wasn't because of nos. It was just boost pressure. And the fact that there was lots of weight hanging on the manifold.

It doesnt seem like lots of guys drag race here. But I like corns to. But no where here for that type of racing. Launch on 2 dont work. Lol. Jump and there goes your money.

Edited March 18, 2015 by MJTru

[MJTru]

Hardsteppa your profile info is a total flam. Kml. Wouldnt be surprised if your a island boy. Your sure as hell not 75. Kml

[MJTru]

Cant believe that there is no drag racing info on here like that

[GTRPSI]

OK so in a nut shell, your question relates to the shocker setup in rear wheel drive drag setup, right?

90/10 front shocks, 50/50 rear shockers.

It allows the front to lift to transfer weight to the rear and resists the front coming down quickly.

Simples.

[MJTru]

Ok. Maybe it was my mistake by not giving details on what im looking for.

1. Does pineapples work. Is it worth the money.

2. What kind of shocks will give me those kinds of adjustability.

3. It taking the sway bars off a good idea has anyone done it.

4. How about positive 1 degree camber good for drag so it should go flat whiles on the power.

5. Does 1 to 2 kg springs good. ??

Thanks for any help you guys can provide.

[GTSBoy]

1. Pineapples do help. A little. You can set them up to get the best out of the subframe angle, which is probably 0.5% better than not. They do lock up the subframe a lot though, which can help to get rid of the sort of slop that leads to axle tramp and so on. Worth it, and cheap.

2. Drag shocks. Literally. 90/10 is a description of a fixed rate damper where the bump damping rate was literally about 9 times as much as the rebound damping rate. Allows them to extend more easily than they compress, so you get the weight transfer result GTRPSI mentioned. Not ever having given 2 shits for drag racing, I've never cared how you go about buying them. They were either off the shelf items that damper manufacturers were making to make the drag racing / street machine crowd happy, or they had to be made by revalving normal dampers. Doesn't matter. These days to put something like that on the front you'd probably buy a 2 way adjustable damper, set the bump damping a bit on the firmer side and the rebound damping all the way soft. Probably wouldn't come out to be 90/10, but would still give a result in the desired direction. As to the rears, a more normal damper is the go there. Still 2 way adjustable though, so you can tweak both the bump and rebound damping to get a) the compression right so it squats the right amount and b) sort out any tendency to tramp or hop by fiddling the rebound.

3. Can't see it being a good idea. It will lighten the car, which might help trap speed, but the effect of rotating the body relative to the wheels when you launch is somewhat countered by the ARBs. I wouldn't expect it to be pretty without them. ARBS tend to redistribute load on one wheel over onto the other wheel. Can't be a bad thing, surely?

4. You could try running pos camber to get some neutrality, or at least less negative, when loaded. Whether it works or not will really come down to the whole combo - spring rates, damper settings, power level, tyre type, etc etc. If you have a big loads and lots of squat, then sure it would make a lot of sense to do it. If you have small loads or a stiffer setup that doesn't squat as much, then it could hurt. Unlikely to hurt, but possible. I'd start with zero camber and video the car on launch to see what's happening.

5. Way too soft. Stock rates are over 2, pushing 3 depending on the car. I wouldn't think going softer than stock is a good idea. The reason is a little complicated. The problem is that the rear suspension on Skylines is not a good design. In fact it's reasonably poor considering how much better they were able to make it at the time. So you don't actually want to encourage lots of squat. Squat is the enemy of grip with these rear ends. If you had a solid rear axle then you could go for soft springs because the squat you get would be desirable. But you don't.

The main thing to consider is that if you make all the suspension setup choices to best suit drag racing, then the car becomes a liability when driving on the street. if it doesn't go on the street, then perhaps go right ahead. The

[MJTru]

Thanks for a detailed explanation GTSBoy.

What I was planning was having extra parts like camber arms shocks and toe arms all labeled and ready for the drag strip and after swap them back out. I just want a set of shocks. And arms all set for the strip. Switching that set up back to stocl or orginal is easy for us.

I can remember back in the past shocks had oil in them and now they are gas shocks makes them hard to valave. Thats my concerns about the valving idea.

Where I can get shocks that are oiled based inorder to revalve them would be the issue. I dont think skylines can have such a bad rear suspension setup. Its just that its independent rear suspension thats all but I see supras that scwat good and looks to have lots of grip. I just need a setup that will work. I've seen lots of independent rear suspension cars hook and launch out. But its a bit harder without a prep track but the physics remain the same I would think.

Ok first off can you tell me were to find a shock or some that can provide a set of shocks with the following specs mentioned above. 90/10 and 50/50 rear.

Thanks appreciate your time to answer.

[GTSBoy]

All dampers use oil for the damping medium. All. Good ones also have nitrogen gas in on top of the oil to prevent foaming. It improves the consistency of performance of the damper. Whether or not you can open up a damper and revalve it depends on a few factors, and whether it's gas charged or not is actually not one of them. Of course if it's gas charged, then it is definitely a specialist job.

Read Gary's (SydneyKid) sticky at the top of this forum.

The Skyline independent rear is a not real great design. The rear suspension on A80 Supras is much better, and it still isn't that great for drag. Great for road/circuit, not great for drag. Those independent rears that are good for drag are those, usually by Euro manufacturers, where the suspension design engineers were allowed to spend what they wanted to get a good result in all areas. Later Mercedes and BMWs can be good examples. Early MErcs and Beemers are actually pretty crap too, but that was pretty much standard for the era.

With ref to your statement that you've seen plenty of IRS cars squat and go, just keep in mind that what is true for a really good IRS design is NOT true for a not great IRS design. Squat is not that desirable on a Skyline. You need some, you get some, but you don't want lots.

As I said earlier, I wouldn't know where to go to get old fashioned "drag shocks". I recommended that you go fully adjustable dampers in order to get what you need + tunability. If you're lucky, someone might know where you could get the old fashioned stuff for a Skyline, or whether you have to buy something simple and get it revalved.

After you read Gary's sticky, you could contemplate sending him a PM and ask for guidance. He is a bit of a suspension guru - definitely less about drag than circuit, but at least he should know where to point you (if he has the time).

[MJTru]

Will do mate. Ive seen it its somthing like suspension 101. And have glanced at it in the past. Like 8 years ago I had a mate offer me a setup. I cant for the hell of me remember his name. But his profile photo was of a r32 gtr with 1101hp converted rwd. Just for drag. it was white in color. He had mensioned that he uses blisten shocks and he has done some setup on r32 gtrs but he said yhe r33 gtst is quite close in weight and design. He was the one that told me how to do the reat brake down grade and what size E/T drags to get. He was on point. I wish I could remember his name. Thanks again I will read the thread you mensioned.

[MJTru]

Think I found him jas/slo32 do you know if he is still active. ???

[MJTru]

I was looking and found these for a s14 240sx which would bolt right up to the r33 skyline.

[MJTru]

Hi we are working hard to get this car tuned for quart mile.

[MJTru]

We still have alot to do. Last week we lost heads up to a 2jz supra. That wasnt a problem our problem is the car setup for launch. But lets say we know why the competition didnt show up today. Hats off to rickypr33 for a great by run basically.

[MJTru]

My mate had to learn to drive the car all over again. With the tire and proper suspension setup (some what) the grip was insane for the street that is. He bog down at his first attempt and gave the race away to a supra. The car is on 18psi and if we can get a bit more grip. We are planning on uping it to 22. 1.5 bars.

Is there any other home made liquid I can use that better than water to get the tires going. For burnouts.

Edited April 6, 2015 by MJTru

[GTRPSI]

Is it bogging down all the time or sometimes?

Or does it bog down on launch and once it picks up again there are wheel spin issues due to power?

Did you end up putting positive camber in the rear and watching the car to see if it squats enough to take out all the camber on launch?

[Ben C34]

Bleach is heaps slippery. Was good for getting shit cars to smoke up one wheel back in the day....

[MJTru]

Is it bogging down all the time or sometimes?

Or does it bog down on launch and once it picks up again there are wheel spin issues due to power?

Did you end up putting positive camber in the rear and watching the car to see if it squats enough to take out all the camber on launch?

Well the car has the power to spin up the tires all the way. We want a little more grip off the line so we can crank the boost. I personally dont drive the car mate but feel two thinks I can do here. Do more suspension work more squat but for the moment I raised the rear and used stock springs. But I moved the stock spring perch / seat as high as I could get it. I needed to do this to gain camber. I still dont have lots because we arnt running camber and toe arms as yet. There all stock. On one side I have -.8 camber and the other is -1.2. And the bolt cant adjust no more. But ill get it when the parts reach. We also running stock shocks. I need a shock with compression settings cant find them, but im looking now at the s14 240sx stuff as its the closet rear shocks if not the same.

Im planing on having the total rear end travel be 2 inch. The car sits 15 inch from center of rear axle to the quater panel line. I may go up half an inch more and after im happy with the rear ill do the front. But ill use some bump stops to keep it within flat camber or no more that

-.5 on launch so that way the contact patch stays around flat +-0

Its harder than it sounds mate takes lots of time and trial. Any suggestions im all ears mate.

Bleach really

Shit im going to the states for my work s1 wheels ill just get some VHT.

[GTSBoy]

Just a couple of points.

1) Bleach is slippery on the fingers because of what it does to the oils in your skin. Not necessarily any more slippery than water on the ground under a tyre.

2) VHT makes grip, not slip. Opposite of what you are after.