yeppers...

 

Oh, I thought you told me you were running more pressure in the rears last year (only 2 psi more, which I guess is consistent with what you say above).

Anyway, I needed the extreme pressure difference (10 psi higher in the rear) last year to compensate for the fact that my rear diff was worn out and almost completely open. I just did my first event with my new TRE-rebuilt diff, and I thought I'd start with 35 F / 37 R. Well the car was too crazy and I spun entering the first slalom. I then tried 35 F / 35 R and it was pretty well balanced. Easy to get trailing throttle oversteer, but I didn't get it accidentally.

The coolest thing was that I can now point the car with the throttle again! For the first time in two years, it doesn't feel like a FWD car, I can get the tail out by stepping on it. Thanks TRE!

Mike

 

As I said in my previous post, I just did my first event with the SCCA club at Devens. The good news is I think I won BSP. The bad news is I blew my engine. It was my own stupid fault. I forgot to check and fill the oil for this first event of the season. I was only 4k miles from the previous oil change and I hadn't raced the car at all since the oil change. Turns out I was down at least 2.5, probably 3 quarts, after only 4k miles. The oil pressure light never came on, but something bad happened near the end of the 3rd run.

I hard a loud tapping in the upper end, and even though there was no loss of power, I knew something major was wrong. A friend who knows the 4G63 engine better than most thought it might be a collapsed valve lifter. After adding oil, I followed his advice by bringing the RPMs up to 3K (while parked in neutral) and holding it there for a few minutes, then letting it drop to idle, to see if the tapping was gone. The third time I did this, it stopped idling and ground to a halt. Attempts to start produced only the click of the relay. Engine seizure.

Once it cooled off, the starter was able to turn it over very slowly, but not fast enough to start. Looks like it's time for a new short block.

This engine had 60k miles on it, but only half a season racing under increased boost. And yet it burned 3 quarts of oil in 4000 miles in the off season. Something was definitely wrong with it.

Anyway, I'm taking the car to DSG to have them open it up and see how bad it is, but I'm pretty sure I'm looking at a new short block. On the good side, maybe I'll make more power with an engine that isn't burning so much oil!

Mike

 

that sucks....

guess I should check my oil tonight, I got a long trip and the car hasn't run much all winter..

 

Nah, I'm REAL careful about only driving the car when warm.

Yea, I launched it. Dumb, I know, but it was a members-only event, and it was the 1st time I had a chance to mess around with the car with all this newly found power. 56k miles, i'm not heartbroken about it. SHep has a TC for me they're rebuilding now, should be here next week.

No more autox launching for me!

 

Hey Mike,

How many miles were on your OEM Rear Diff? I just changed the fluid in my rear diff and there were a lot of shavings on the draig plug, so I'm thinking mine is certainly weaker than it was when new. I have 56k miles on it, how many on yours before the rebuild?

 

Are you talking about using the 2-step to launch? If so what RPM?

We missed you at CART on Sun. I got FTD. Booyah!

 

That's about what I had on my rear diff when I had it rebuilt. Keep in mind, however, that I have an '03 that I've been racing in autocross for 5 years (and 1 or 2 track events per year).

These clutch-based diffs definitely have a limited lifetime as far as the limited slip goes, and when used hard, it looks like 50k is about it. Jon Ripple says that the rebuilt one should last longer, because with the extra clutch plates he stuffs in there, there is more surface area absorbing the friction, or something like that.

Mike

 

Whoa, its LEO!

Yea man, I had a final exam and a presentation to take care of for school.. it was too much to take the day for CART

I heard you beat Nick's time. GOOD! Let's make sure at least one of us does every CART event for the rest of the year!


Yea, I 2-stepped it at 5k. Way too high for autocross, I know, but I was having fun with all of this HP I wasn't used to this car having. No biggie really, SHep has my TCase now and hopefully she'll be running proper again next week.

 

Cool, thanks for the info Mike. I have 50k on my car, but it was an older man's car before mine, and I've only been autoxing this thing since last August. I want to drive someone's Evo w/ a stiff rear differential to compare; that'd be real helpful to determine the state mine is in.



On another note.. my Bilsteins are shipped!!!!!

 

Question for anyone with tire temp experience. I'm getting some peaky inside temps in the front something like:

Inside:115
Middle: 103
Outside: 102

It's kind of odd since the outside spread looks ok, but the inside is very peaky. The overall spread isn't totally off. My codriver thinks it's a combo of too much camber and low pressure. Thing is the car is fast, no notable lack of front grip or other odd behavior. We did add a couple pounds of pressure to the fronts but the front started to feel pushy so that was backed off. No real change in temps either. I'll post up the actuals for the whole car later tonight.

BTW, Thanks Marshall for the hoosier pressures, we ended up around 38f 37r on a not so grippy surface in 50ish degree temps.

John

 

I'm not that much of an expert, but that sounds right. The car rides on the inside when you're going straight, combine that with toe out and the inside never gets a chance to cool down. If the middle and outside were different I'd say work on the camber a little.

BTW, I meant to stop by and introduce myself at the NNJR T&T earlier this season, but never got a chance. Any plans to stop by a Philly Region event at Warminster this year?

 

I agree with GT, you almost want to see 10 more F to the inside from all that I've seen..

 

I run zero toe in the frt, so I guess the camber is the main culprit here. My total spreads inside to out are typically in the 10-15 range, so I'm not outside the "norm" discussed in most books, the spread is just not very linear. My guess is that when it's loaded the spread is great and with your (Dave & Justin) insight I guess the numbers look good. If I decide to run some toe in the front I guess temps would increase, presently I'm not having any turn in issues though.

For sh*ts and giggles here's a look at the entire car from this weekends event:

FL: 93/94/107 --- 114/104/101 : FR
RL: 86/87/87 --- 87/87/88 : RR

Front AVG: 102
Rear AVG: 87
If the front evg exceeds +18 or so the car is usually feeling pushy, or overdriven

Left AVG: 92
Right AVG: 97
There was a long left hand sequence before the finish, so these temps are skewed a bit.

Cross Avg 96/93

I gotta say too the A6 is pretty kick ***. Def feels different than the V710 but we wont be making any real changes to the car besides tire pressure adjustments.

Dave,
I was thinking the same thing at the NNJR event and we were even driving cars right next to each other, go figure. My hope (and Dan's too) is to hit Warminster at least once this year.

John

 

Yeah, I can see your right side is toastier. Locally our lot is so sandy I only see temps in the 115+ on hot days..it's like being on ice sometimes..

On another note I may throw swaybars back into the mix on my car this weekend. I have been running without the rear bar for a while and the front has been disconnected. I hope I like it, they are annoying to put on and take off.

J