Under heavy acceleration or high speeds my front end seems to lift making my steering feel 'dodgy'.

I'm running a 2007 HR with tein flex, hotchkis sways (full stiffness), cusco a arms and the camber at just out of manufacturers spec.

Anyone any ideas

 

Under heavy acceleration ANY car will have NO steering.

Now as far as high speed? Are you on a track?

Swaybars might be too stiff upfront... tire pressure... do you see what I’m getting at ?

 

Yea i understand that, just seems excessive

Yea, but also on the road and i can feel it at 60mph up, and the faster you go the worse it is. Feels like the front end is floating.

Yea understand, tried that type of thing. strut settings, sway bars, camber, tyre pressure. None of that seems to correct it. I've got it a bit better playing with settings etc but still not right i don't think.

 

i don't know man... if you are sure that alignment is good... it may be something mechanical. my car is rock solid @ 130+++ with no aero mods


how bout your rear alignment as well ? is your toe-in correct ?

let me see the numbers !

 

did you do any of the following?

1. remove stock under-tray?
2. have aggressive front camber or toe?
3. have the front higher than the rear? (i.e. reverse rake)
4. have a massive rear wing, bigger than mine, set for maximum downforce that makes you do wheelies?

 

Ive been running with my oem diffuser off and have no problems like that.

 

Tire sizes please

Amount of drop front and back

If your not on R comps, your sways are way to stiff. Soft rear with one up from soft front is great with most street tires. If you have sticky street tires NT05, R1R's , Escta XS etc etc you can go up one stiffness front and rear.

Also need your damper setting ( your clickers)

 

I'm running the stock 18" Rays with 225/45 bridgestone 040s front and 245/45 Toyo T1Rs rear

My alignment is front camber -1.32, toe 0 and rear camber -1.37 and toe 0.03

My tyre pressure is 37psi all round.

My tein flex are on 8 clicks front and rear and 63.5mm from the ground to fender at the front and 65mm at the rear.

The stock under-tray is in position and only the oem rear trunk spoiler.

As for my sways, i understand they seem a bit stiff esp on road tyres but having run every setup they don't effect this "floating" and this setup feels the best on the twistys. I also have powergrid end links btw

 

So is that 37psi hot or cold. If thats you cold temp, it should be lower 34 to 35. Next change you sway settings to the first settings i mention. Last, the stock front tires suck, they suck bad, swap them out for a set of T1r's in 245/40.

Slight toe in up front will also help, and can be done within factory specs.

 

hmm.. mis-matching tire brands... potential issue there?

with that little camber, i doubt it's tramlining... try a lower cold tire pressure..

also. try setting up a slightly raked setup where the lower in the front is more than the rear...


it's going to feel light as far as under acceleration is concerned, but for high speed runs.... the car in factory trim should have zero front and zero rear lift, granted you didnt screw up the balance when setting the coilovers...

 

Oh chit, i didn't notice that. Checking my setup notes on the last couple cars , he should have close to a 20mm difference in wheel well height from front to back. (rear higher)

Screwing that up is the same as putting equal height tires F&R on the car, and changes caster. Adding caster on the Z makes it twitchy as hell.

 

Thanks guys, i'll give that a shot.

Yes it is cold tyre pressure and i've got some 245 PS2 for the front and 275 PS2 for the rear going on soon which will sort the mismatch.

I actually have 15mm of a difference front to rear as those messurements in my last post should say cm not mm. 63.5 & 65 mm ground to top of the fender would be pretty low.

I'll check my caster settings when i get home but as far as i remember they were in spec too.

 

Lets forget the acceleration issue, as you've said that will happen, and focus on high speed runs. How could i have screwed up the balance? Zero preload all round, 8 clicks on front and rear and the ride heighs mentioned above. Anything wrong here? Anything else i should of done?

 

Caster is 8.29

 

balance as in front to rear weight ratio. did you corner balance the car with the alignment? or compensate for the weight of the driver during ride height adjustment?

can you please describe the issue a bit more more? does that mean you're having alot of play between the steering left to right and the car is not following the steering inputs?

i dunno maybe that's just how your car is...