DRAG WHEEL/Tire setups

NIZZING

[QUOTE=andre12031948;2566313]You should be doing 10.8's 10.9's[/QU


That's the goal.

andre12031948

Your 60' is what's hurting you. It sucks but your mph is great.

Your susp. set up is more for show & or road driving. You still may have room for the right size tires but will have to make a few changes if you want better drag times. You got a whole winter to think about it.

My 350z with very few bolt on mods with slick did 1.6's 60'(all day) with less than 300 h.p. Atco & Raceway park. So you see how much better times you can do?

Easier to explain on the phone, or at Atco if weather is OK.

L.I.??? shop???

ts-c63

why dont your get a used set of base 18inch 370z wheels they will clear the rear brakes. wrap them in radials and call it a day, your beast can deff hit 10.9

andre12031948

www.youtube.com/match?v=CSXcQwhVfvc

Except this car has WEIGHT TRANSFER & tires that dig in.

GSS138

Are you getting wheel spin at launch? Standard gear box and final drive?

If so, your answer is actually bigger tires in the rear. Can you tell me what your torque and rpm are at launch typically? I can show you some math and stuff if you have a general idea how much torque you are generating at launch. I can't even dare guess on that monster u drive lol.

edit: Also do you know the weight or corner weighs of your car?

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phunk

EDIT: (Revised for 2018, current with my experiences since originally commenting)

The ideal and proper way, is probably more commitment to drag racing than most Z owners are looking for. Small rear brakes, like the 350z non brembo in the rear, will allow a 15" wheel. Use a proper drag slick, 26" or 28" x 10.5". I recommend the 28" for taller sidewall and to have an effect of stretching the gearing out a little bit. If the car is a manual trans, make sure you are using a bias ply slick, not a radial. Run the softest suspension you can, which means all stock or dedicated drag shocks. Align the car to remove as much negative camber as you can. Run the car at factory height so that the higher center of gravity can be used to transfer weight. Obviously make sure you are doing a healthy burnout, and slowly dial your tire pressure down after each clean attempt until it hooks. You will probably end up around 18-20ps on a bias ply. This is the best you can do. And it will do pretty good (1.4 or 1.3 60's with practice, we've done it. A well dialed in car can probably do 1.2s like this).

For a street and road course setup, it gets very difficult and its hard to say what is best. It probably becomes very sensitive to exact combos. The IRS in the 370z is particularly terrible for drag racing and/or hooking up high power. Even the slightest compression in the rear causes extreme camber and short sidewall tires cannot deform to accommodate that. Slamming the car on stiff springs and shocks removes the vehicles ability to transfer weight to the rear tires. You have lowered center of gravity which reduces its tendency to lean back, and the added spring rate and shock dampening again makes it even worse. Everything is working against you for hooking up in a RWD car setup like this. It takes traction to make more traction... without even a little bit of grip, it cannot accelerate enough to begin weight transfer or squat. Starting with the control arm angles of a lowered Z, the compression camber is compounded, going more negative with even minimal travel, even if you had aligned to a baseline of zero. Basically you are fighting fire with fire here, and you shouldnt expect to achieve anything great. If you somehow do, please let us all know how you did it!

For driving on the street, run the suspension as high as you can stand to look at it. Run the largest drag radials you can fit, on the smallest diameter wheel are you willing to run. Run the pressure as low as you can tolerate the vehicles handling at. Basically, get as close as you are willing to get to the ideal setup I mentioned above. With 18" wheels and drag radials, stock shocks and springs, and clever torque-reducing boost-ramping we have been able to get a 700whp Z to usually hook up second gear on the street. As cool as a Z looks slammed to the ground on 19s or 20s, I promise you that if you feel second gear hook at 650+whp, you will be posting all that stuff for sale.

Aside from that, if you refuse to go anywhere near it and want to go slammed and low-profile tires and big brakes... at that point all you can do is align to zeros in the rear, and run a drag radial with as low of pressure as you can tolerate the handling at (without going so low to ruin the tire or lose the bead). 1.8s is probably going to be the typical best 60' you can get like this, maybe you'll get an occasional 1.7 with practice, and I would be shocked (but intrigued) if anyone does better.

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DEpointfive0

Where have you been? I don't see you post anywhere, lol

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andre12031948

Doing ONLY 1.9 60' is meaningless. A 600+ H.P. + good turq. should do 1.4-1.6, or don't bother. My old car did 1.6's all day, so I know what that type of car/H.P. should do/must do if you want low 11's, high 10's.

A Nismo is designed for road driving, drag racing needs weight transfer. A Nismo's suspension is too stiff, but with much soft rubber of a SLICK, good drag racing is still possible..........

Chuck33079

Take a look at the drag times for FI cars. Only one guy has touched a 1.6, and he was on drag radials. The rest of the list is closer to 1.8 regardless of tires. Launching a boosted Z is tricky.

Also, Phunk is one of those guys who knows what he's talking about. Rather than saying something is meaningless, you should be taking notes. You've had a 370 for less than a week. He's been engineering and developing parts for the platform for years.

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GSS138

Based on what phunk said might even run a bit of positive camber if you can.

Also, I would expect that the problem with 500+ hp beast on this car would be wheel spin. That basically means you are traction limited, since you never want to limit HP, you have two ways of fixing it:

1. More vertical load at launch. Particularly difficult in a car that has a 54/46 F/R weight imbalance on OEM suspension. That's why I ask for corner weights. The only real option on OEM suspension is to move some weight to the back.

2. You can increase your tire radius. Use a lightweight. 18" wheel as suggested and get a big fat tire on there that has a rolling radius of > 1 foot 24"-26" or whatever fits. This will help balance out the "too much torque at launch" problem.

Once that problem is solved there are lots of other options to reduce time. But that is paramount.


Phunk , do the big squishy tires really allow for enough front-back weight transfer that you don't need to soften up suspension? I'm asking I have no first hand knowledge of dragging this car. Are you saying the problem is that if too much load is transferred , this car cambers out too far and you lose grip? How about starting at positive camber?

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Chuck33079

Embrace your inner redneck. Throw some bags of sand in the hatch.

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GSS138

Either that or get some 2x4's and some rope and drive from the trunk.

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phunk

A 1.8 or 1.9 and some more grip through first and second would give him a 10 second et... So meaningless is obviously relative.

Of course, a 1.6 would be great! But it's not going to happen on KW coilovers and 18-19" wheels.. Don't blame me for that!

And yes, using a soft slick and weight transfer is ideal... But that's exactly what I said in my post

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phunk

I am saying that unless you have big squishy tires, as in real squishy like a real drag slick, that you not want weight transfer due to the camber this car generates.

Normally you want weight transfer in the back. But that weight transfer does you no good on drag radials because it reduces your contact patch to nothing. Example... If I do a rolling second gear burnout, the patches on the road are about 2-3" wide. My tires are 315/30/18. With stock shocks my car squats a lot, and to make it worse, I'm starting with crappy control arm angles by being lowered a lot on springs, causing the camber to pull in even faster with every bit on compression. If I put stock springs in, I would get more contact as my control arm angles would be better. If I put in real hard shocks, it would get better yet, as there would be less compression to cause camber.

Starting at positive would be ideal, especially if running all stock suspension and soft slicks... But nobody here is going to do it... It's too far into the drag only realm.

What I'm saying applies to this car and this car only (and 350z). Not all IRS cars have this problem... But this is why you don't see many fast Zs. It's rare that a Z owner is committed enough to go to full slicks and small wheels/brakes. But without that.. 1.8-1.9 60' is all your getting. There's tons of 350zs that have had the power to go single digits... You can probably count on one hand how many have done it.

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andre12031948

I said your post was a good one!!!!!
I was referring to the person that owns that 600+ H.P. car. Also people can't just say that traction can NOT be gotten by a 370 Z. That's crazy, there are cars including ZZZZZ's with much more H.P doing 8's & 9's at the track

OF THE TOP OF MY HEAD.

VINNIE TEN with their boosted car are/did do low 9's. That's my point! 600 H.P. is great but you have much more powerful cars & ZZ's doing 1.4's, 1.5's & I found NO PROBLEM, with my nothing of a car doing 1.6's ....... So fix that problem, don't say we can't.

By the way, 3/10's gain at the start 60' = apx. 5/10's at the finish line!!!! FACT !!!! APX. maybe more????