boosted DD with occasional 1/4 mi set up help.
 

I've asked questions like this before but I figure I post it in the drag forum and maybe get better help.

First off, I'm a suspension noob. I know some but not enough so explain things to me like I know nothing. That way, nothing gets overlooked in your explanation.

mods:
-stock suspension other than urethane rear diff bushing
-boosted on spring pressure at a estimated 470 hp. I want to turn up my boost and hit 500hp/430 tq (it was turned to power level)

*I will get the RJM pedal to help with clutch control sometime soon.

I DD my car and maybe 1 a month, sometimes 2x a month his the 1/4 mi strip. I either bog at launch or spin like crazy while I HOP down the front end of the track till partially in 2nd gear. I want ot turn up the boost but 500ish hp/430 ish tq but what's the point if I cant lay it down and hop around all day. Plus I don't feel comfy hopping down the track because it really breaks the drivetrain down. I don't want to break my car.

What is the best/best bang for buck fix to the wheel hop? I feel that if i can get that under control, I will get way better 60' which means 11's. Please explain why this mod or mods will help.

How much will it cost and what brand to look into. I will most likely DIY it as I like to tinker so put that into consideration.


YzGyz

sticky rubber is typically a good place to start. then flatten out your suspension in the rear for best chance of getting grip. from there it's work on your launch technique and learning what works best with your car's power and the track conditions.

What you mean flatten it out?

YzGyz

get rid of the rear camber.

when you get on the throttle the car squats which increases camber which decreases the amount of rubber you actually have touching pavement.

less tire contact = less traction.

Will doing that kill my tires during DD? I do most of the driving as DD. I don't want to compromise tire life all month for 1 or 2 days at the track.

Trying to do track things with a DD is a so much of a compromise. They really are not interchangable. I'm not trying to do track dedicated times. I'm just trying to get 11's.

Can I adjust this myself? I'm thinking not.

YzGyz

probably will increase tire life but lose a slight bit of handling if you go carve a backroad or something. with even the OEM camber wears out the inside of the rears pretty quickly.

rear camber arms can be adjusted by you but without an alignment machine i'm not sure how you could dial in and out camber and be exact aside from maybe marking lines on the arms where flat and DD normal camber is?

not really a suspension guru for these cars as I live in PA and DD mine so no suspension mods on mine lol someone else may have to shed morel ight on that for you.

Another thing you can do is to change all of the rubber bushings in the rear to spherical bearings. SPL parts. Rubber bushings let the suspension move around.

Next would be shocks adjustable for both compression and rebound. Adjust the front shock full soft on rebound and full stiff on compression. This will let to front of the car come up quicker and hold it there longer. More weight transferred to the rear. Two ways to adjust the rear shocks. Adjusted the rear shocks full stiff on compression and about 50% to 75% on rebound. This will make the rear harder to squat and will not let the rear raise up to quickly. Or adjust the rear shocks full soft on compression and full stiff on rebound. This lets the rear end squat and not let it raise to quickly.

Which bushings are we talking about? That seems more doable and keeps my car more street able than messing with the springs and shocks.

YzGyz

A better diff will help as well something like a quaife if its a daily driver you will feel the benefit on the strip and on the road.

I found my RWD R33 Skyline launched best with the rear shocks set to full soft but this increases the rear camber and reduces the contact patch of the tyre but the weight transfer gets it hooked up quicker

do you drop your rear tyre pressures at all on the strip ?

I would get a cheap set of rear wheels and drag tires... Takes 10min to swap them out on track days. Thats what I did with my RX-7

Be careful with full solid bushings on drag applications. Its not normally the rubber that is causing the issues as far as wheel hop and traction. Maybe the diff bushing, but when you go solid on the others you start to see broken axles and broken diffs, as the rubber helps absorb some of the "shock" on launch.

As for what may help, good shocks and good tires will be the best bet, nail in a good alignment. What are you tuned on? ECUtek has some real nice traction control options that may be of help also.

All comes down to budget, if you can put up between $1200-24000 for shocks we can get you a set built to your needs. Tires will be all over in price depending on what you choose.


The best thing, will be practice. The more you take the car to the track, the better you will get at driving it.

I've found that the rubber bushings in the Z will let the suspension move enough to cause issues. Plus they do not move freely in the intended direction. ;)

Is it any specific bushing you have found that causes the most issue? Im normally a fan of the Urethane or Nismo bushings (If they are around) over a full spherical for a street/Occasional track car.

There is deflection in all of the bushings. You add each bushing together with the rest. It makes for alot of monkey motion. And there is enough stiction in the bushings. If you remove the springs. The knuckles will stay in place. They will not droop down. I've replaced all of my front bushings with SPL bearings. Planning on doing the rear this winter.

I have a set of HR rims that might fit my Z. They are 19/10 +44 offset rims. I was looking into some drag radials. I was looking into NT05 or toyor888 as i can get these at Discount tires. I'm scared that if I hook and hop with the added grip, I will bust my rear axial from the loading and unloading from wheel hop. Each hop is like pounding a on the rear drivetrain with a sledge. I don't want that.

As for what alignment are my rears set at? Probably OEM specs as I have yet to get an alignment done. I think I will on Friday at Break Check since they have a cheap plan for unlimited alignments. I might even go today.

As for the launch, I'm working on that too. IMO it's just about impossible to launch with the SZ 6puck clutch kit. It's pretty much an on/off switch. Everyone stalls taking my car out the first time. Hell, even I stall once in a blue moon if I don't pay attention. These is just no play to let you ride the clutch. I get 1/2'' to 1'' of clutch pedal travel between fully engage and fully disengage. That's why RJM is on my list.

Ad for the budget. I was hoping it would be a simple fix for like $500-$700. Darn!

Please continue to comment on what I can do to help me lay the power down. Yes $$ is limited but, They might not be in the future. However, try to keep it realistic as I have to work like everyone else for there $$.


Thanks again my friends.

YzGyz

(slimmed down above post)

but if you want drag radials go with the Nitto NT05R or something more along the lines of a mickey Thompson et street 2 maybe even hoosier's dot radial offerings.

the 888 is sticky but more for cornering. the other DR's listed have a tire compound meant specifically for drag racing. and remember to drop the PSI down on them too for the best chance of max grip. nice little burnout as well to get some heat in them.

also the stock axles in the Z are strong from what I've seen/heard so far. to be honest even the 600whp+ Z guys haven't really mentioned swapping them out unless i missed one or two builds.

I'll have to ask or shop around got some nt05. Looked online and most places don't catty them. I need a tire that can make the drive to and from the track. No way I'm I loading 2 big azz rims w/tires and a jack around to and from the track.

As for the snapped axial. My buddy has snapped 2! He has way more power (600+/600+) and a 1.5 way diff in his G35. Like I said, I think the wheel hop is the thing that is killing the launch and drivetrain.

YzGyz

i wouldn't daily on DR's. it's a massive waste of money since they're so soft they will just melt away fast.

best bet spend money on spare set of rear wheels and go with MT ET street 2's or Nitto NT05R.

i would always get wheel hop in my RX-7 on street tires (sumitomo HTZR III i think) but when I would throw a drag radial on the back I'd hook with no hop. I got hop so bad once I ripped my trans mount out (LS1 swap).

Ive only had my Z at the track once and raced with street tires and had a lot of hop. The one hard launch I had with no hop my clutch let go. If I were to continue taking it to the track. I would upgrade the clutch, slave, and clutch line and get a set of drag radials on a cheap set of rims.

No No, your misunderstanding. I have a set of street rims/tires (OEM RAYs w/so4). I have another set of HR rims as stated above (rim size 19/10 with +44 offset) that I plan to put drag radials on to swap the back Rays out for drag days if the rims fit well enough. They can't be strictly Drag use only tires because I will have to drive to the track.

YzGyz

depends on how far the track is really. I mean if it's not really far a short drive wont destroy the tires.

I thought you meant DD on the DR's. my bad lol

Yeah, DD drags would be a big waste of $$. The track is 1/4 mi is 50 mins away. The 1/8 is 30 mins away.

YzGyz

yea personally I wouldn't go that far on them just to preserve the lifespan of the tire.

I have been looking and researching what rear wheels I would want (and can fit) to make a drag set-up. I would just have someone follow me with a jack and tools to swap them out at the track.

I don't have anyone that willing. That's "retarded" in there opinion. Why drive 50 minutes, help lug tires in and out of the car to watch you have fun as I sit around people stare at light, smoke and junk for hours.

Anyhoo, that;s why I think the nt05 might be the right choice. Now for the wheel hop.

YzGyz

ahh that sucks. maybe find some local car guys who go and maybe one takes a truck or something.


as for wheel hop that's someone else's department. I never had it so I don't know what you need to fix it.

If you are on stock rear arms you might run out of camber adjustment before you get to 0 camber. I'm all the way adjusted and can't reach rear camber. You might get there since you don't have aftermarket springs.

Why not just order from TireRack.com? You can order anything you want and get it delivered to an installer of your choice.

Because they don't carry Nitto at least on there site. I would If I could.

YzGyz

Pretty sure Johnny can get you those

Ill have to ask him next time I stop by. Didn't think of that for some reason.. LIKE DUH!!! Jonny and the OLD GUY!!

YzGyz

Alignment and basic suspension mods and decent tires will do the job. 500rwhp isnt that bad. Its around 575+ that I find these cars to become a big hassle. Dont lower the car too much and keep the negative camber in the rear set to barely at all negative, like half a degree maybe. Get some 18x11 or 18x12 rear wheels and put Toyo TQ 315 drag radials on them. First gear will still give you a hard time on the street but otherwise it wont be too bad. At the track you can drop the pressure and do a decent burnout and get it to stick pretty well. Theres more you can do but it doesnt sound like you want to get real wild with it... 500rwhp is relatively manageable anyway IMHO. Oh, if you get a boost controller that lets you ramp in the boost as ground speed increases, that just makes a world of difference.

I already have those rims is the shed. That is the only reason why I even consider getting DR. I'm not in it enough to lay $$ down for a set of rims just for DR tires.

As for the Toyo, I just looked on the TireRack site and they don't carry them in the 10 wide, 19 diameter size.

As for the boost controller I have the TuboSmart Eboost street. I don't even have it hooked up right now because I don't know how to use it yet. I'm waiting till after I finish my DIY pod before I hook it up. In addition, I don't know how to wire it so that it can boost by gear or speed. I think I can do it but IDK.

RJM clutch pedal bought. Hope that helps with modulating the clutch for better launch. After that. I plan to practice riding the clutch, gas and use the E-Brake to hold the car still and launch.

YzGyz

I wouldnt have different drag radial wheels either, I just drive on drag radials full time. I do have a set of 15" wheels for even better drag radials that I occasionally put on though.

Ya 19" makes the tires really low profile on a car that uses such a small diameter tire. 18" would be better. Having sidewall allows the tire to conform to the pavement better and will tolerate the compression camber more when you have some sidewalls and put the tire pressure lower.

Depending on your setup, you might have to change your wastegate spring to use boost by speed. A boost controller cannot allow you to turn your boost down, only up... so if your wastegate spring is high enough that you have traction issues, you would change the spring out for a lower one, then use the boost controller to increase boost with speed.

I can't drive around on DR full time. I DD my car full time. rain or shine. Just not smart with DR. I understand about the sidewall thing but it's not an option as I can't/won't get a smaller rim and go through the trouble of removing rotors and calipers just for 1 night a month. Then drive 50 mins to the track, hopefully get 10 runs in then drive home.

So the simplest thing to do that can potentially get me better times is DR (will a 305 fit on the 10'' wide rim?), camber to 0 or even a little neg for when she squats. I'll have to find me a Break Check place with lifetime limited alignment that is willing to put the rears out of OEM specs.

Any answer on if I need the toe bolts for SPL camber arms? Reason I want SPL is I read good thing about them if you plan to hit the track. I don't want anything snapping on me as I have read about SPC.


Thanks you all so far for helping me out. I'm at a total lost is this stuff. Thanks for your time and knowledge for the help. Anyhoo, feed me more info. Me likes the brain food.

YzGyz

I daily drove mine for years! Heck it was my only car for a few years. I just didnt drive it on snow, otherwise rain or shine no problem. My TQs were fine in all but the worst rain, in which case, I just had to slow down a bit. 18s actually fit over all the stock brakes.

I dont think I would run positive camber for the street, plus that would look hideous!

Take it to a performance shop that does alignment, they will set it wherever you want. I wouldnt want a entry level tech at one of those chain jobbers turning wrenches on the car.

What it comes down to is that you are going to find yourself in the same boat as most guys with a high power 370z: no traction. Everyone wants it, but its not important enough to the average 370z guy to actually do what is required to get it.

Its fine though, 500rwhp isnt that bad. Just some really soft high performance tires and no camber and closer to stock ride height should do you fine as long as you arent trying to get good 60' times at the track.

So DR for DD is ok at 500ish HP. The problem is that the TOYO don't come in OEM Nismo rim size. If I'm gonna DD, I might as well look good doing it. I'm not chasing crazy numbers really. I just want to hit 11.75s in the 1/4 mile. I think that's reasonable if i hook it ok me thinks. I did 12.89 on S04 and spring pressure at 7.5 lbs which my estimate is only 470 ish RWHP.

What other DD tire do you recommend that will somewhat last and hook well?

YzGyz

I have never personally found a non-race compound tire to hold power on the street. But if I were to try hard to seek one, I would start with the tires they put on all the factory high power cars, the Michelins. I dont know which... they have several high performance tires and they all have almost the same name so I cant ever keep up which is which. But just look up like what the new Z06 runs and try something like that... at least, that is where I would start my search.

A couple years ago I ran a 11.7 or 11.8 or something like that on the Toyo TQ 315 with my 18x12 wheels.

Ya you are going to have a hard time finding a drag radial for a 19" wheel that has the right diameter for a 370z, because that skinny sidewall is sort of counter-productive. Nitto has some NT05R 19" drag radials that I run on my Mustang, but they are in the 28" diameter range to have some sidewall and that diameter doesnt jive with the 370z, ive tried.

Get some 18's and never look back. My 18s fetch 3x as many compliments as my 19" TE37s ever did. The car looks a lot more business on 18s! I swear!

Plus 305/35/18 is like the perfect rear tire size for what you are talking about, and there are tons of (r-compound) options in that size. Tires are also quite a bit less expensive in 18"

I guess I'll really have to track Ron down at the shop and ask him what he thinks. It's just a little hard finding him with all the races and stuff.

I've read about you and Jwillis I believe car on the stang forum. Lots of crazy stuff there with high HP and drag racing! I also snoop around in the Camaro forum too. MAybe one day I will buy a c7 and read that forum too.

Edit: I think it's Wiggins.. not Jwillis

YzGyz

They make a ton of power, the latest Whipple tunes are making 750-760rwhp at 12-13psi with 93 octane all stock engine of course... its pretty nuts.

But believe it or not, I have found that the 2015 Mustang IRS is MUCH worse than the Z at putting down the power. I have had to replace tons of stuff back there and I have more boxes of parts I have to swap in as its still not very good yet. Everything bends and flexes so much from the torque that its killing my rear tires every 2500 miles due to how far out of wack the alignment goes during full throttle.