be prepared for a long and misspelled ramble.

last time i took my Z to the track it was a bad joke. it was two and a half years ago. i had the sleeved block in the car. i was making the 573rwhp at 14psi. i had my 295/35/18 BFG drag radials to fit over my big *** stoptechs. running my tein flex coilovers with the car slammed. i tried a run at 10 psi of boost, which was about 520rwhp at the time. i spun in first, wheel hopped thru second, blew the headgaskets and shot coolant on the windshield, then missed 5th gear and coasted to a 11.6 at 122.

3 weeks ago i got my car aligned on the street setup. even with all the JIC adjustable arms maxed out, they couldnt get a damn thing in spec. this is probably my fault for running the suspension slammed. i keep the rears adjusted bottomed out compeltely, and the front just barely tucks the top edge of the tire.

on my street setup, the thought of traction below 60mph is a joke. thats if im lucky and on good pavement. sometimes it takes until 75-80 to not get any slip when the boost hits. this is running any tire i have tried so far. the last year i ran the pirelli pzero corsa r compound 295/35/18.

last year when putting my car back together with the unsleeved block (my aebs block was the one with the headgasket issues), i decided to do some measuring and order some decently serious drag tires and wheels. i realized i would need to flare my rear fenders a little to fit what i came up with, so i did so... somewhere between 1/8 and 1/4 inch we flared them out and of course completely rolled the lip in. i took out the rear springs and jacked up the suspension and i have about 2-3 sheets of paper worth of space between the sidewall and fenders. looks awesome and perfect. i dont think fender clearance is an issue for me tho, because i knew i would put the stock suspension back on the rear when running them, and it sits pretty high on that, i dont imagine it squating enough to tuck the tires anyway.

so at any rate, i decided earlier this week that i wanted to go to the track today. its not going to happen, here is my short story about why not.

i took the teins off the rear to swap in the stock springs/shocks back there to get it to be softer to help traction. i took the stoptechs off the back and put on some stock nonbrembos to give me the brake clearance for the drag wheels. i already had extended nismo studs at all 4, which i needed for the drag style wheels and lugs. what i ended up with looks awesome.

now, its already a pretty decent amount of work when you decide you want to hook up in a straight line to have to go and swap your springs, shocks, brakes, bleed brakes, change wheels/tires... but i can live with that, i rarely care to drag race from a stop anyway. With the teins my camber was maxed at like -2.2 or so... now that the rear is at stock height without adjusting anything, it looks like its sitting at a perfect 0 camber, which is cool for drag racing anyway, so i was like "sweet".

with the front still slammed, my car has so much rake to it right now that even with the brights on i can hardly see down the road. ok, i can live with that too. what i cannot live with...

this car is all over the road now. this must be an adverse effect from not realigning the car now that the ride height in the rear is 2.0-2.5" higher than when it was last aligned. the toe must be all crazy now. when i floor it in 3rd gear, LOOKOUT, cause i cant keep this car within 3 lanes. its hooking up awesome, especially with the tires warm, but it is just plain out of control and unsafe. it pulls all over the place under full throttle, and the faster im going the worse it in. in 4th gear i almost killed myself.. dont ask why i tried it.

so now what i am realizing is, on top of all the other work i have to do to swap between my awesome handling and braking street setup to something that can actually use the power the car has in a straight line, i have to go and get the car aligned every time i switch. grrr, what a pain in the ***.

on a side note, i installed my 3" SGP downpipes with open dumps. i swapped in 10.1 psi springs. if i wake up early enough, im gonna go strap it on the dyno and tune it for higher boost. i lost wheel power when i swapped in my 3.3FD. my 6% change in gearing resulted in a 6% drop in rwhp. i want to get that back and more. my 573 at 14psi went down to a 546 at 14psi. this is SAE corrected, at STD corrected it was 583rwhp at 14psi. dynojet of course for me.

i am also going to go in for an alignment today. first im going to raise the front end like an inch... this extra rake from raising the rear is making my front lip smash into absolutely everything. i am thinking that rather then adjusting my spring perch in the front to raise the car up there, i might get some aluminum shaft collars to put under the springs, that way my street setting is "saved", and i just take the collars back out to return to my regular riding height. hopefully this alignment will fix the problem i am having, i will report back. as soon as i get the car tracking straight, i will head to the drag strip. broken parts or 10 second timeslips lay soon in my future.

basically i am just frustrated that i cant have my cake and eat it too. i like having my super street car, i just wish the damn thing would hook up without all this hassle.















here are some pics when i took out the rear springs to check for fender clearance. like i said, i dont think the car will ever squat this far on the stock suspension... but i wanted to know that these would fit if ever ran them with my teins, or if i ever put some drag springs on. remember, this is AFTER i flared the fenders out.

 

heres the specs on my drag racing brew for those of you interested in getting this tough look on your Z.

the drag tires are MT Street Radials, 26 x 11.5, 15 ". Part # 3753R.

the drag wheels are Weld Racing drag-lites. 15 x 9 w/ 5.5" backspacing (+12mm). Part # 59350.

you MUST have nismo extended 60mm wheels studs for these wheels.

you MUST have the right style lugs for this. McGuard part # 63003 is what I have.

this clears stock NONbrembo brakes perfectly.

if your ride height settings are going to tuck the tire, this setup will slam right into your fenders. remember, i flared my fenders for this. if you running stock suspension like i run when i put these on, you will most likely not have to worry about it as i dont think the rear end will ever compress far enough for them to hit. however, no promises, maybe it squats more than i realize. be ready to flare your fenders, which may require paint work if your paint cracks... i did it before painting the car so we didnt care.

 

good luck man!! its good to see more people drag racing. its not easy to keep high hp cars going in a straight line.



remember, less is more....

also, i would love to see those dyno graphs, for example on my STD corrected (which i always have used since day one) chart i posted last night the 592 in SAE is 583. i have never seen such a hugh difference in the two corrections, usually around 2 % .


tips for straight line high hp goals, get rid of the powersteering and get skinnier tires on front.

 

Hola Phunk!

I had a similar set-up on my G, same tires but 16" on 300ZX wheels so no fitment issues. I did get my car aligned for drag racing and the result was many broken parts (3cv joints, 3axles ) even slipping the clutch to avoid harsh engagement and more level 5 broken axles. DSS told me that the problem was the hard sidewall of the MT drag radial. Changing to MT Street should alleviate the problem because the softer sidewall will absorb the impact on the drive train. Also even with an easy launch (2.0sec60ft) the MT Radials will break loose on second gear, so I was not impress with traction either. Best ET was 11.3@128 with 2.0sec60ft.
However this could be a problem only on the G because of the weight difference . Good luck with your project!!!!

BTW still waiting for the twin pump setup

 

In theory, 0 camber should be perfect but with our cars, espescially when running street tires up front I feel having factory spec camber gives you better correction down the strip.

Do you have a 3.3 diff? If not, you should go with a 28" tire. Thats what I run with a 1/2 drop in the rear w/ cut fenders.

I run 15X8 welds w/ 275/60/15 ET Street Radials

Lower boost + Taller Gear = easy 10's for you!

 

sounds like caster is your problem

 

What are you using for engine management now?

 

Phunk....go to the drag section and look at some of the pics from Bradenton last weekend. I believe everybody but one350zfan has stock rear suspension and the cars squat like a mf'er. Good Luck with your setup

 

Charles-you do not need to swap suspension to run good times man! I run 14k/14k suspension, you can still get out of the hole with minimal rear squat!

It sounds like you are having the same type of issues as me on slicks/radial but yours is worse. I suggest you raise your car, re-align it into spec, and make sure the wheel base is the same on both sides. I believe mine is slightly off from using traction rods tro adjust toe, its not the correct way, you should use eccentric bolts. Also, run as narrow a tire on the front as you can so your car wont be hyper sensitive to steering input. You have more than enough power to run 10's with out changing so many things on your car!

 

I agree with you^^.. IMO you want to have a rear suspension that is just firm enough to get traction without that extra wasted movement of squatting too far.I think one350z fan has it right on his car like I said above.

 

Plus 1 on the tag.

 

i went to get an alignment today. the alignment was fine. i have a few things to look into that i will elaborate on later when i have more time.

 

..

 

Was this with the factory suspension in the rear?

 

hi, pls can some body help me , i can keep the stock rear suspension on my Z when she'll be more then 500hp ? i affraid when i wanna drag with this power to have a lot of spinning on ground especialy when the asfalt is not hard, ? if i should change the rear suspension, what kind of to replace the stock suspension ???
thx
joe

 

^^Is this one of those word scramble puzzles?^^

JK. I believe that for drag racing, the softer rear springs on the OEM setup is preferable to road racing style coilovers. I had 560rwhp with 295 PS2 street tires on the stock suspension and stock camber settings, and could easily hook up halfway through second, as opposed to guys with coilovers and less power spinning all the way through third on DR's....just food for thought. Plus for my style of driving, the stock suspension handles well enough for me in the turns.

 

ya this was with the stock stuff still on there.

the car was aligned when slammed a few weeks ago... maxing out the JIC arms they got it to about -2.5 camber and i cant remember what toe they got it at, it wasnt in spec but it was even and as far as they could go.

so when i went yesterday with the stock stuff on there, with the settings being untouched the car was sitting at -0.5 camber with driver side toe at 0.09 and pass side at 0.03.

looking around at things i noticed that my pass side tire looks like it sticks out of the fender just a tad bit more than the driver side. then i noticed that my driver side traction rod is set longer than my pass side, its got 6 threads left while my pass side is maxed out with no threads left.

i talked with jeremey at pf and alberto ()thanks for the help guys) a bit yesterday and so far what i have come up with is that this car needs to be aligned by a race shop and not a laser 4 wheels system. what i am thinking is that the wheels are all aligned with each other when the car is sitting stationary, but they are not properly squared with the chassis, and having unequal length adjustments is causing uneven dynamic toe changes during compression and decompression which is making the car pull when i nail it hard and it hooks. thats the theory at the moment. i am taking the car to AMS this week to get it squared up by justin, their in house guy that aligns their race cars.

if this theory is the actually the problem, it makes sense that i never really noticed it on the other tires and suspension... on the teins the suspension hardly even works at all, so this characteristic wouldnt have been very expressive, now that the suspension is moving and weight is transferring due to traction, im getting a lot more compression and therefore movement back there.

in theory, i could put my stock traction arms back on here with my stock LCAs, and go get the trear aligned to stock spec and hopefully all would be well. how far positive on the camber can you go on stock suspension with just the eccentric bolts? i like the idea of my -0.5 at the moment, can stock arms take me that far in?

 

Car looks sick, with those drags in the rear.

 

With the eccentric bolts and stock arms, Id think you can get at least -1 degree of rearcamber, that is good enough to hook up with the tires you run...nice talking to you yesterday, keep us updated on the situation.