Did you find the higher pressure in the rear help you rotate the car (less understeer)?

Mark Daddio suggested to me a 10lb. difference between front and rear (higher in rears). He does like a very loose car, probably looser that most would like. I have found 5lbs higher in the rears a good compromise for my Victoracers.

Opinions?

 

When it comes to rear tire pressures, there are two ways to loosen the car up -- by going high or going low. Both work. On the Evo, I have run rear tire pressures as low as the upper 20's and as high as the upper 50's. Both extremes work. The thing to remember is that in trying to get more oversteer/less understeer, you are trying to decrease grip at the rear. For a given setup, there is some pressure at which the rear will develop maximum grip. If you go higher or lower than that, you will get less grip and more oversteer/less understeer. FWIW, I ran 40f, 29r this past weekend and was probably a hair too loose. A couple of weeks prior, I ran 38f, 51r (IIRC) and was probably a hair too tight...

JW

 

I prefer to pump up the rears rather than lower because it tends to reduce the contact patch area whereas lowering will tend to increase the contact patch area (more grip).

Also if you think of your tires as springs (suspension) increasing the pressure is like increasing the spring rate.

That being said anything outside the envelope will probably yield the same basic results.

The courses that I run tend to be short and tight. If I have an aggressively oversteering car when I am "on" I get a fast time. But if I make a mistake--not timing the trail braking correctly for instance--I am scrubbing off speed hence the compromise of the 5lb. difference between front and back.

Although whatever works best works best. The proof is in the pudding and what is best for each driver.

 

I've been trying different settings, some of which were posted in this thread (thanks).
The setup that's working for me currently, with V710's, is 35psi FT and 40psi RR. -1.8 camber FT, -1.0 RR... 0 toe front, with toe out rear (not sure of the angle... just turned the bolts about 20 degrees).

 

Are you running 245/45/17 or 275/40/17 V710s? If I ran 35psi in the front on my 245s, the shoulders of my tires would be toast within a few events. I'm running roughly the same alignment.

 

245's. I tried the pressure higher and lower... lower than 35 would have a little roll, much higher than 35 and I wouldn't be using all the available "tread". I've done about 7 events on the v710's and wear has been pretty even.
My driving style (tends) to lean toward late apexing, occasionally trailbraking. Get the turning done as quickly as possible... not prolonging the amt of time the tire is on the shoulder.

 

Interesting. I've found that anything less than about 44psi in the front wears on the sidewalls and not the tread. What are you running for shocks/springs/bars? I was assuming stock springs given then title of the thread.

Do you autocross in MN? I'm originally from there. Do you race the MOWOG autocross series?

 

Yep, straight up stock everything on my '03. I'll need to change the shocks soon, one is leaky after the last event.

You originally from Minneapolis area? The MOWOG series is the main points series that I do around here. Just barely out of 1st place for the year (Z07 vette was beating me early in the season, and I've been winning the last few events). One last MOWOG event this year on Oct 2 will decide it...

 

Saw this in another thread, lools like Ohlins is going to make OEM strut/shock replacements. Works is going to package them with other springs it looks like, which you won't be able to use if you are running AS, but I'm guessing they will sell them without too...

http://www.worksevo.com/store/produc...roducts_id=292

JW

 

Sweet! Thanks for the info. If they're are priced decently, I'm definitely going to look into that setup.

Now if works will just produce that adjustable front sway bar. I've had my deposit on it for 6 months now...............

 

Is anybody running a setup off 17x8.5's with 245/40 Yokohama A032R Soft tires? Any suggestions on a base tire pressure setting? I am just about ready to get into my second autoX event and a first on this tire wheel setup. My '03 is mostly stock with the exception of an HKS intake and a turbo-down 3" pipe. Thanks.

 

Actually you'll be running in BSP with those mods. Stock class only allows same diameter and width as OEM for wheels, offset can vary 1/4 per side. FYI, most guys on 17's in SP are running x9's or x9.5's w/255/40 or 275/40 sized tires.

 

They actually put me in SM class since we only have about 20 to 30 entries a series and only have three classes which is S,ST, and SM.

 

A couple of new front sway bar choices that I just found out about are from Swift and Tanabe. I don't know anything first hand about them, but for those of you looking to get that body roll under control, these are possibilities. I saw them at http://www.evasivemotorsports.com/. And of course there are the Cusco and Works bars too...

JW

 

Is the Tanabe 25.4 the largest front bar available?

I'm probably just going to go with the drill an extra hole in the stock bar route. But I'm cheap and lazy...

I was thinking that for AS, a bigger front bar would work well with a 275/245 F/R combination. But unless I can find someone that sells a 3mm spacer (RPF1s with +35 offset), I may just stick with 245/245. Anyone know of a vendor for the 3mm EVO spacer? Tirerack said no. Although I guess I could get the 5mm and have them machined down to 3mm.

G