Help with traction

[Towelie]

Okay so I went out racing the other day, and holy shit its damn near impossible for me to launch without blowing the tires off. I'm just looking for some tips on what to do beside the obvious shocks and struts.

my suspension mods are:

275/60/15 ET streets, had them at 12 psi
BMR solid LCA's, poly poly
BMR adjustable UCA, poly
BMR relo brackets, LCA at middle hole, UCA on upper hole (gen 1)
scott drake phb (this thing is going in the garbage soon)
Eibach pro kits
and the stupid part, stock shocks/struts.

Could I get a few recommendations on shocks and struts and other tips? I'm trying to keep the budget small, but i don't want to repeat the other night, it was embarrassing. First launch I tried launching off the 2 step at 3500 rpm, and when that didn't work I just launched by holding the revs about the same. after that i just got pissed off and frustrated and went home.

 

[eighty6gt]

track prep

 

[Towelie]

lets just say I run no prep.

 

[palanza7]

different tire?

 

[2011/5.0]

No prep =slicks

Sent from my XT1585 using Tapatalk

 

[skwerl]

Are your front struts adjusted all the way soft? Have you disconnected your front torsion bar (only one side is necessary)? The front end needs to be loose in order to rise up easier and transfer load to the rear.

Are you running the radial ET Streets or bias ply ET Streets? Either way I think 12 psi is too low. IMO they get too squirrelly at the top end with less than 18psi. When I ran the radial ET Streets I would use about 19-20 psi at the track for best results.

 

[Towelie]

factory struts, no front sway bar.

I'll turn up the pressure and see what that nets me. M/t recommends 12-18 psi for my weight on the et street radial if i remember correctly

 

[skwerl]

Also take another look at your UCA. Adjusting those can be trickier than it appears at first. Call up Kelly at BMR and go over the adjustment procedure with him, he's a frikkin wiz at that stuff. And he loves helping people with it as well.

 

[Towelie]

you don't have his number off of the top of your head do you

 

[lindertw]

275/60/15 ET streets, had them at 12 psi
BMR solid LCA's, poly poly
BMR adjustable UCA, poly
BMR relo brackets, LCA at middle hole, UCA on upper hole (gen 1)
scott drake phb (this thing is going in the garbage soon)
Eibach pro kits
and the stupid part, stock shocks/struts.

Could I get a few recommendations on shocks and struts and other tips? I'm trying to keep the budget small, but i don't want to repeat the other night, it was embarrassing. First launch I tried launching off the 2 step at 3500 rpm, and when that didn't work I just launched by holding the revs about the same. after that i just got pissed off and frustrated and went home.

factory struts, no front sway bar.

I'll turn up the pressure and see what that nets me. M/t recommends 12-18 psi for my weight on the et street radial if i remember correctly

radials with a stick shift is hard to get right (it can be done, but it's not very forgiving and can be tough to tune for suspension wise for the average weekend test-n-tune racer).

my $0.02:

- bias ply rear tires (hoosier QTP is the way to go since M/T discontinued their bias ply ET streets)
- older cobra jet springs (p/n M-5300-Q) work well if you don't want to slam your car, otherwise go with newer CJ springs or BMR drag springs
- strange single adj struts/shocks (I want to say they're about $450 for the front/rear set)

- UCA in upper hole (you're there), if adjustable set pinion angle to -2 degrees
- LCA in middle hole (you're there)
- front sway bar removed (you're there)
- front struts full loose (if strange single adj)
- rear shocks +7 clicks (if strange single adj)
- hoosier QTP bias ply rear tires at 15psi cold
- launch at 6500 rpm
- profit

 

[Towelie]

hm, seems like if I go bias ply that will help a lot. my pinion is already set at -2 also.

now that 6500, is that on a prepped surface?

 

[travelers]

Are you running a stick or auto?

 

[lindertw]

now that 6500, is that on a prepped surface?

ideally yes. I get a little bit of wheel spin if track prep is poor (or if I follow a car running street tires at test-n-tune). Bias ply tires make a significant difference.

I'm putting down 329rwhp/350rwtq, running a stock clutch, stock 3650 trans, stock 2pc drive shaft, eaton truetrac diff, 4.56 gears and 26" bias ply tires - launching off the limiter at 6500 is a hoot

 

[07 Boss]

QTP's on those 15" rims is your first step. Drag springs and adjustable struts and shocks. Plot your suspension geometry and play with your antisquat %. There is no magic number, all depends on your set up. Anyways, just take that front sway bar off. I took mine off and gave it away a long time ago. Stiff rear sway bar too. I went with the BMR Extreme. I might have some Viking dbl adj shocks for you. Let me see if I can find them and if they are still in good shape.

 

[Towelie]

Are you running a stick or auto?

stick

ideally yes. I get a little bit of wheel spin if track prep is poor (or if I follow a car running street tires at test-n-tune). Bias ply tires make a significant difference.

I'm putting down 329rwhp/350rwtq, running a stock clutch, stock 3650 trans, stock 2pc drive shaft, eaton truetrac diff, 4.56 gears and 26" bias ply tires - launching off the limiter at 6500 is a hoot

unfortunately track prep is a luxury I don't have a chance of getting.

QTP's on those 15" rims is your first step. Drag springs and adjustable struts and shocks. Plot your suspension geometry and play with your antisquat %. There is no magic number, all depends on your set up. Anyways, just take that front sway bar off. I took mine off and gave it away a long time ago. Stiff rear sway bar too. I went with the BMR Extreme. I might have some Viking dbl adj shocks for you. Let me see if I can find them and if they are still in good shape.

front sway bar is gone. You have my phone number (at least I think you do, i remember hitting you up when I was in spain) if you find those shocks hit me up lol

 

[skaarlaj]

If you want to be able to adjust pinion angle, and only want either your top control arm or your bottom control arms to be adjustable, Which do you guys prefer? I'm guessing top so you're axle will stay perpendicular to the car with fixed lowers? I'm also guessing stock pinion angle is a little more than -2 because of the softer bushing material?

 

[Marble]

The upper gave me a lot of adjustability. IME the pinion angle is something to think about but really has never changed my 60' at all. It just reduced vibration at speed after a drive shaft change.

I also would consider the lowest hope in your relocation brackets. It may not work but it won't cost you anything.

 

[BMR Tech 2]

Pinion angle isn't going to change your ability to hook, it just prevents driveline vibration.

Your problems are no prep, manual trans, radial tires, your springs, and your dampers. You're going to have a hard time launching a stick car with no prep (especially on the street, which is what I assume we're talking about here). There is just too much debris and oil on the street to get a tire to hook well, the stiff sidewall is also hurting you. There is not as much sidewall flex to absorb the initial hit and leads to traction issues. Stock dampers and those Eibach springs are also not your friends. You need to be able to slow that hit down with the shocks, control body movement coming back up, and get a spring that isn't so stiff that it won't allow weight transfer.

Ideally you would want to do all of that, but if you're trying to keep the budget small, focus on driver mod and ask your tuner to soften the tune up for the hit. If you have some money to play around with, shocks are probably going to be the most critical component to making the car work better.

 

[deepimpact]

305 45 nittos here and only thing I did was 50/50 rear drags running tvs with 6 speed. sounds to me like it's the track?

 

[travelers]

Bias ply tires work better with stick cars, it lets the car plant the tire because of the softer side wall.