"Hey" my daily driven race car!

[icehouse]

Carter made me do it!!!!!












I think I need another set of LED headlights.

[eastbaysolo_73]

Nice I love mine as well.

[icehouse]

Well.... after all these years of autoxing the rest of the field has either learned to drive or bought Hoosiers. Now I'm usually 5th in RWD and 7-9th overall.... Damn! I'm dynoing my car tomorrow. I wonder if maybe it's down on power. My guess is the guys are just learning how to drive there cars. Dave says I shouldn't be bummed since it's still on stock brakes, only has a NA SR and it's in the unlimited class. Which I agree. I just miss smoking everyone haha. Either way my coupe is almost done and that will give me room in my shop to turbo this car. I'm excited to see what another 100hp does for my lap times. Also I can get the prototype rear suspension in and do some new front dampers. At the same time I can't have it down for to long. They do a race every 2-3 weeks! Don't want to miss to many!

[icehouse]

It made 126RWHP about what I expected.

[bertvorgon]

Make sure you pick a cam(s) that give you a WIDE power band. I also ran a small turbine housing to compete against well set up naturally aspirated, carb'd cars at the time.

Throttle response is key when doing slaloms, ever more so as they get tighter. You do that race course too, so getting out of corners fast is so very important, requiring both STICK from tires and then power right away.

There was a sound reason to run 4:62 rear gears, cheap form of HP and ballistic acceleration. I of course coupled that with the fact that I was running race tires that were either 20" or 21" tall, totally helping with gearing.

Sure, there is a trade-off to top speed, but, in reality, how much top speed do you need VS ACCELERATION !? With my well built engine I can still pull 8,000 in 5th so do have some good top speed.

[icehouse]

I mainly wanted to dyno this engine to see how much HP I will gain at the wheels after I install the turbo SR I have and how much different the times will be. To be honest 126WHP is getting kinda boring. I had a bunch of ride alongs so this event my times were kinda everywhere. The previous event from my first to last lap I only improved 1.2 seconds after 12 laps. I know my car pretty well. I want it to be more scary to drive haha!

With the super low gears did you ever find yourself shifting to often? I don't hit the rev limiter very often with the 4.44's and a 7500 RPM limit. It does happen at some events though.

[icehouse]

Here is the dyno chart. I don't know why the dude didn't rev it higher.

[bertvorgon]

As we discussed on the phone, slaloms and events that are always changing the course, make it impossible to make a car that is good at everything, specially when it comes to gearing choice.

Yes, on some courses, specially as they got tighter and smaller, I would have to shift a LOT! In my case, with short gears and really short tires, it made 2nd and 3rd very useful. Even with my taller 2.9 first gear I would just wring the motor up on the line, load the clutch to get boost, launch and short shift to 2nd gear, better to get the car stable than scream the motor in 1st and then shift when power and torque can really upset the car.

Having a useful power band sure helps and as we discussed, scoping out a course and then seeing where YOUR car can use it's strengths can be critical to staying at the top of the heap. I used to maximize my acceleration wherever I could, as that was my cars strength! When you consider that at some point, with a group of competitive cars in terms of suspension..EVERYONE comes under the same laws of physics when it comes to cornering grip.

That then means you need to look at both corner entry and what does that exit lead to?

Yup, you are down on power if you said most of those other guys have 300 HP, so they, like me, are putting down around 250 to the rear wheels. They should be way heavier than you so getting out of slow corners faster is key.

I once raced an brand NEW STI up a mountain road once, kicked his ass all over the place. He stopped to talk to us and I said he really has nothing to worry about as I had over 1,000 lbs LESS weight than he did...why would I not out accelerate him going uphill!?

Let me know how that spring change goes, I suspect that did not help things. A "rain setting" is just that. We used to put a steel block in the rear of Tracey's car for rain races at Westwood, amazing the difference it made for traction.

I put my son in the back of my GTS for a slalom once, where I picked up 2 seconds with him sitting in the right rear and that car would not then spin the rear tire.

[bertvorgon]

http://users.telenet.be/AudiR8/Carroll% ... %20OCR.pdf

Not sure if I ever posted this link up..takes you to Carroll Smith's book; "TUNE TO WIN". It was one of my bibles, I even built a full size cardboard replica of my Mcpherson strut to see how things moved as pivots etc changed. Wish I had kept that.

While a good chunk of it is really aimed at REAL race cars, the information holds for the most part to our family sedans that we TRY to make into a race car..he has a chapter dedicated to: The Peculiar Case of the Large Sedan.

I have always loved the TRACTION CIRCLE and live by that still to this day, even when driving my Honda Odyssey, tires can only do so much and understanding weight transfer in our 510's is key to be able to drive them fast..IMO.

[icehouse]

I checked the diff clutch breakaway last night, its at about 50lbs. Seems fine. Could the clutches just be worn out? I've been testing and it seems to do 1 tire fire pretty easily. I'll swap the springs for the next event if it isn't raining. I like the idea of extra weight in the back for rain events.

[edekalil]

Love the super sonic grill remake, I have for the 2 door I'm fixing back up. And love your car.

[icehouse]

Today I decided to do a real weight ballast test in my car. So I signed up for 2 spots in today’s autox. 12 laps with 40lbs in the trunk an 12 laps without. I tried 80lbs last autox but that was way to much.

It turns out that the 40 lbs just slows me down. It requires smoother driving. If the rear starts to come around it’s harder to catch with the extra weight. Thus smoother driving is required which in my car is a little slower. My car is fastest with a little sliding sometimes for extra rotation.

24 laps is a lot. Even with power steering my arms are tired.

[icehouse]

Some pics from the last month or so.

[bertvorgon]

Weight in the trunk INCREASES the "POLAR MOMENT", so it is not surprising that once the rear gets loose, it is harder to catch.

we used to put the "rain weight" on the seat floor, passenger rear ( not the foot well).

How did you like the 6 degrees of castor?

[icehouse]

Weight in the trunk INCREASES the "POLAR MOMENT", so it is not surprising that once the rear gets loose, it is harder to catch.

we used to put the "rain weight" on the seat floor, passenger rear ( not the foot well).

How did you like the 6 degrees of castor?

Yeah I thought maybe the added traction would offset the polar moment as you call it. Now I've went the other way. My 510 has always had a leak somewhere. Rear floors get wet if it rains a lot. Well it's been so rainy stuff inside has been molding even though I drive it everyday. I removed all the carpet, rear seat, boys seat, rear panels and that tray cover. They are going to stay out until I Get the leak fixed. Wonder how autoxing is going to be with at least 40 less lbs.

My tan car only has about 4 degrees of Caster. I don't have the top of the struts back 1" like they need to be. Hopefully soon I will wehn I install my S13 coilovers.