My setup is turbo itr making 330whp at 10psi. Suspension is omni sport 12kf 10kr lowered about 3'' all around, stock sways. Brakes are stock itr calipers, russell lines and hawk dtc60 front and stock rear pads. I'm using 15x8 wheels with 225/45/15 nitto nt01. WHen I brake hard at the end of a straight away the back end of the car drifts to the drivers side everytime. It's moderately easy to control but I"m just wondering what can be done to improve the issue. I'm slowing from about 200kph-85kph so maybe I need some rear aero? Also could lowering the rear end slightly help to keep the weight on it?
Thanks, any help is appreciated!

 

Your rear brake isnt locking up is it?

My guesses are rta bushing could be shot? or an alignment issue? Not really an expert tho..

 

There are a million possibilities. I like jdm's idea of alignment, but I'd also check into some different pads front and rear. You'd be surprised how much bite a stock pad can have. Also, keep in mind that a performance production car can put 80-90% of its weight on the front tires under heavy braking-- it could be a driving issue. Just stuff to think about!

 

I tried stock front pads once and they faded after just a few laps. Will get an alignment and maybe get some more lessons.

 

Long(ish) wheelbase FWD car is just going to do that. Alignment and setup are the biggest factors. Toe and dynamic toe change with droop make a difference.

This part helps a lot with toe change.


http://passwordjdm.com/PasswordJDM-R...1854C1926.aspx

Also the Kingpin complience bushing.


http://kingpinmachine.com

 

Good suggestion on the parts

 

I have the same thing happening with a similar setup on my car. Front ITR calipers with DTC60s and HP+s in the rear.

I'm throwing a set of HP10s in the rear this weekend to try to see if that helps out.

 

On a FWD Honda, one of the first things to check when you're having loose rear problems under braking is the rear trailing arm bushing. If there are any visible cracks, it isn't working properly and you should replace it. Often gets neglected, but having one on there (spherical or otherwise) that is doing its job makes an enormous difference in stability under braking.

 

Thanks guys I was planning on doing the rear end next year. I have spent a small fortune on this car this year trying to locate a clunk in the front end. I have replaced everything front suspension wise and probably do the steering rack next to find that damn clunk. My rta bushings looks good and I have no play when I shake it hard but what does that mean anyways.

This hobby is going to be the end of me.

 

One of the know hazards of starting out with a modified car.

 

So your car is fishtailing to the drivers side?

A 13 year old stock civic could be having the same issues as myself. My car is old, I have had it for 13 years, it has been turbo'd for 11 years and I have been tracking it since 06.

 

For the brake pads and tires you using and the speed you are driving I feel the spring rates in the front are way too light and you are unloading the rear too much.

 

Sounds like the toe alignment under braking is changing if car is pulling to one side. Could even be related to the clunk in the front, as there is not much load on the fronts, and a toe change on one side might cause alignment to make car want to go to one side.

This of course assumes there is no differential side to side in terms of braking force. Try swapping disks and pads from one side of the car to the other. If car moves to the other side under braking, that was you problem. Unlikely it is a difference in hydraulic pressure side to side. Of course brakes are bled properly all around.

Check that caliper pistons move in and out freely on all corners of the car when you swap parts side to side. Also check that pins in caliper are freely moving and overhaul those to be sure calipers are functioning correctly.

I run a turbo ITR with Hawk DTC-60 pads front and rear and have never had the problem you describe. Just came back from doing about 120 laps and brakes worked well all day, no pulling to either side.

Have you replaced your ball-joints in front, tie-rod ends, rear toe compensator arms?

Have your car put on an alignment rack and then have tech put pry bar to various parts of the suspension to see if alignment changes differently side to side. Lots of these suggestions are very low cost.

 

Listen to this guy.

I've had bad alignments, cross member bolts loosen up, seized brake caliper, brake pads on one side in backwards... You NAME IT... Yet in all those cases, the car never felt darty under braking (except when the rear tow was like 1/8" tow OUT!).

All the times the car felt darty under braking was caused by one thing. Dynamic toe. Something is moving and in my case it was the right tie rod, then 4 months later it was the left tie rod.

 

My car doesn't pull it's just loose under heavy braking. I like to have some rotation in the rear especially when trail braking into a corner however I find that with the DTC60s the rear gets a little too light for my liking.

I've already upgraded to the PCI spherical rear trailing arms as well, I'm running 450lbs springs front and rear which could be contributing to the issue as well.

 

check if ur running out of rear droop travel

 

How can car be lowered 3 inches? What is your measurement from fender opening to ground all around? Suspension might be way out of its linear range.

Measure from wheel centre to fender opening, and then jack the car up until wheel is off the ground and measure again. How much droop do you have? Are springs loose at full droop? Beanbag might be right on that. Is droop the same on both sides?

 

THis year I did 4 new nissin calipers, rotors, pads, tie rod ends, extended ball joints, 4 new wheel bearings and new uca. I get the clunk when I stop quickly or when I reverse while turning or on acceleration. All bolts are tightened to spec as I found lots loose and it persists.

So going to get a new rack, pci rta bushing and change rear engine mount because it seems to have movement when under load and get another alignment.

I will measure rear droop and report back.

 

450lb spring in the front is pretty dang soft, especially being as low as you are. That will probably contribute to some funky handling, and potentially have you bouncing off the front bumpstops under braking.

 

oups

 

Sorry, I made an assumption.

Is the ABS on your car working? if so, then I say you can rule out brake problems.

Pretty sure evey one is on the right track with something being broken, binding, or running out of suspension travel. I didn't think you could lower a DC2 by 3 inches

 

Mine was doing something similar under braking and pre corner it would get loose, It turned out to be the upper control arms bushing has play in them. Fixed them and it all went away

We just did complete hardrace bushings on my buddy's car and it was an eye opener to see how bad the bushings where on a 12 year old car with 70k miles on it. at least half of them came out with almost no force. All i know thats just moved to priority one on my list after this race weekend lol.

 

Hmmm mine kind of does a slow wag from side to side about 1" in either direction under hard braking. It walks slowly left, right, left, right...I should also say my car is 10 yrs old but 30K miles on it.

When you load the all the weight up front especially in a car with very little weight in the rear I think it will walk a bit with the stock RTA bushings even in good condition. I'm going to see if the PCI sphericals help with that.

 

Obviously I made a mistake in saying the car is lowered 3 inches, I was just estimating because it's quite low and I installed the struts 6+ years ago and have not touched them since.

I think I found the problem, the strut bushing in the rear lca is loose and floating around. It is contacting both sides of the arm, I'm wondering if my front end knock is the front strut even though I took it out and inspected it. So upgrading the suspension to something more fitting is definately in the cards. No more omni crap!

There is no droop barely. The measurement is 13.5'' middle rim to quarter in the air and 12.75 on the ground.

I want to get one more event out of the car this year, it's going to be tight to get a rta bushing in, get new suspension and change the headgasket that is leaking combustion gases into my cooling system.

 

So all your bushings are stock?