I went to the drag strip today...I could not, for the life of me, break out of 14.3xx consistantly 3 times with really crappy 2.4x 60' times; I guess last time I went I got lucky and managed to pull a couple 14.1x's with 2.2 60' times. What I'm really trying to find out is, I noticed before I lowered my car, with H&R Race (~1.5" drop in rear) w/ Koni, I had better straight line traction. I don't know how much negative camber was added from the H&R's but was it enough to affect my traction?

If the negative camber significantly affects my traction on my launch, would it be a good idea to switch back to stock springs when I go to the drags ( I wouldn't mind, it takes ~30mins.)


Also, does anybody have any suggestions on what I should set my koni's (f/r) to when I drag? If full stiff or full soft better? Please educate me.

Help me out here.

Thanks.

wow, are sigs are almost identical, actually if i took a pic now with my gc/konis and my stock rims, they would look identical.

anyway, you guessed right, you lose some traction with your newfound negative camber. if you think about it, your straight line footprint has been reduced in order to maximize your footprint while cornering. the more static negative camber you have, the worse your acceleration times will be and the longer your braking distances. i think you may want to swap springs at the track like you mentioned.

i would set your front konis as soft as possible (for more weight transfer) and set your rears to soft/mid level. also, another trick is to remove or at least disconnect your front sway bar. we used to do this on our mustangs way back in the day (when i was into american iron).

Yes it will. The negative camber will become more pronounced as the IRS squats when you launch, further unloading your rear tire (self sic) contact patch.

To combat this tendency of your IRS you need to adjust your rear suspension so that it is dead on neutral at hard launch.

Regarding shocks, you ideally want 90/10 fronts .. ie strong resistance to rocking FORWARDS and low resistance to weight transfer backwards. Yet you also want your rear spring and shock rates to be ultra hard to avoid the squat mentioned above.

Welcome to the world of IRS where live axles and old timey muscle cars have all the drag strip advantages by virtue of their own prehistoric nature! Getting an IRS car down the strip quickly is not easy.

I see, thanks for the info guys I appreciate it....

hehe nice hellrot joenationwide...

MrBlonde, so you are saying squat on IRS = no good? I thought that a stiffer spring/struts would create wheel hop?

MrBlonde, so you are saying squat on IRS = no good? I thought that a stiffer spring/struts would create wheel hop?

Bump and rebound settings for your shocks in combination with spring rates, tyre choice (and pressure) and the rear suspension geometry for your car will be major players in how your car launches.

There's no easy solution. Anything that reduces the contact patch of your tyres is BAD. Axle tramp is BAD.

The answer is to do your reasearch and take note of possible variables. Remember to screen out the advice that works well on old timey muscle cars but doesn't translate to modern IRS cars. Ask questions from people who run the numbers at the strip. Try stuff one thing at a time and take notes about what works (what impoves your short time).

In our 10.7 @ 134 MPH run we suffered from unloading of the slicks on every gear change, but we didn't get any axle tramp and the 60' time was reasonable without any R&D time on tyre pressures or launch RPMs. I'm not an expert but I am improving my car's launch step at a time following the above method!

It's all good and it's all fun! And remember: drag racers make better lovers.

Bump and rebound settings for your shocks in combination with spring rates, tyre choice (and pressure) and the rear suspension geometry for your car will be major players in how your car launches.


Driver is still the biggest "player" :)

Driver is still the biggest "player"

Absolutely and that is the weakest part in our build ;-)

I would also suggest on all but hyperengined CMod+ autos, the effects on braking will far outshadow the effects on acceleration.

Dan Law