Powderhound,

I basically did the same tranny cooler that Al Norton figured out, following his DIY found here: https://www.6speedonline.com/forums/...996-turbo.html


I don't have a temp gauge, so I typically turn it on manually with a dash mounted toggle switch when the car is running after the first 20-30 minutes of track time. What I have been told by Guards, is that tranny fluid as no place to cool and looses very little heat between track sessions, so the problem is that it builds temp over the course of the day, unless you install something like this.

I'll let everyone know my new alignment specs and spring performance after this weekend at the Glen. I pick up the car tomorrow and head straight to the track. I also have very good baseline times for the Glen from earlier this year (2:10s), so it would be nice to see some improvement

 

Very nice vid.Really good driving.You almost had the cups.

I like road racing very much but not on my turbo.If something happens no way to get another one.

I do shifter karting,it's so much fun and not expensive.

 

Thanks Joe. Your cooler is similar to my set up except I went the air to liquid route as seen here: https://www.6speedonline.com/forums/...il-review.html

Matt is correct. Gearbox fluid really heatsoaks and is very slow to cool. With the cooler running, the hottest I have seen my gear fluid go has been 225F on a +120F track temp day. Normal street driving will bring the temps to the 180s in comparison. I often times run the cooler after the car is shut down to draw out some more heat.

Let me know how you like your set up this weekend. I'm heading to the track on Friday for the weekend so I'll have more data too. Btw, are you AWD or RWD?

 

I am still awd. I have read a bit about the differences and there are diverging opinions. European car did a test a few months back on a 996tt and said it felt faster, but turned slower track times, so I have not moved forward with that mod. What has your track experience been? Do you have any before and after trap times?

 

Joe, there is no question that a RWD set up is faster than an AWD set up on a dry road course. I have data logged ad nauseam at my track and the result is that I'm about 2-2.5 sec faster on a 2.5 mile circuit with 15 turns. The caveat is that with RWD you WILL HAVE TO HAVE a good LSD and you will have to relearn the car and tweak your set up (sways, etc). I do not have PSM. In my opinion, on a dry road course I can put down power to the ground much much better in AWD w/LSD than RWD w/open diff. I also ran my car AWD w/LSD but the steering feel suffers, the car plows a bit more, and the extra 80lbs or so hurts you in braking, cornering and acceleration. By getting rid of the parasitic AWD drag, I am reaching 4-5mph faster speeds at the end of the long straightaway at my track, low 140s v. mid to upper 130s. A lighter car will corner a bit harder, accelerate a bit quicker, and allow you to brake later and deeper. It may amount to a tenth or two of a second per corner, but If you add all this up over a 2.5 mile lap, you will be faster. No doubt about it.

 

Yeah but you had positive there, should be toe in not out.

 

Positive toe IS toe in. Negative toe would be toe out.

 

Hmm yeah I guess you are right when it comes to most north American alignment machines.

My bad, give me a ruler and a set of boxes any day.

 

Fine tuning on the suspension continues and the times are down to almost 1:58 on NT01s. The rear sway bar was swapped for a GT3 sway and the car is much more progressive and balanced at the limit. Oversteer is very minor and easily controlled. GT3 front Cup uprights are next...

 

Here is a rather long update on my latest 3-day track effort that did not go well.

First, the car was not ready on time so I missed the first day The reason it wasn't ready is when I upgraded to from 600lb to 1,000lb springs in the back and asked for the same ride height (130mm) the springs were to preloaded and had no up to give over a bump so the ride was terrible -- we had to lower the ride height to (120mm) in the rear to accomodate and all was smooth again. That however meant that in order to keep the right rake, we had to lower the front to (100mm) and that required removing a spacer at the top of the strut, so that then required realigning and recorner balancing, so that is how I spent my first supposed track day. By the end of that day, I was at last driving to the track.

Morning of day two. I go out and by lap three I am throwing codes and pit in. Misfires. Damn! I replaced the plugs a month ago, but not the coil packs (which even upon close inspection looked fine), so off to Buffalo for coil packs, followed by several hours of trackside install labor by me.

Now Day three at the track with only half a session under my belt, I go out and run some hot laps. Car feels great! Springs are perfect! Then oh no, boost leak problems -- An o-ring on the turbo hose crumbled on the reinstall after coil packs. After some jerry-rigging it's all together and holding boost.

Back out on the track, the car is runing great, and it feels great, but different, so I am slowly building confidence and picking up speed. I finished the last session driving 8 10ths and beating my PR by 1 second (2:09 at Watkins Glen). I know there is at least 1-2 seconds more with this new set up. I just need to get some laps in.

Overall impressions of the new set up are night and day. With the stiffer springs it is a differnt car. Dramatically more planted both in the turns and in braking (though there is a little rear end wobble on hard braking that an LSD would probably cure). It was really crazy though -- it was so different, I actually had to look at my speedo to gauge my speed because it was so much more planted than before. I cannot overstate the differences. Really night and day going from 550/600 to 800/1000 and dropping the car another 10mm.

Current setup is dead on with Powderhound on ride height, but more aggressive on Camber

Front Height = 100 (fender arch 25")
Rear height = 120 (fender arch 25 1/8")
Camber = 3.2 Front, 2.7 rear
Toe = .05 front, .20 rear (forget which is positive/negative but they are correct)
Sways = full soft front, middle rear
Tires = Hoosier 245s F 315s R

Now I just need to loose some weight (both me and the car) explore RWD (which could help with weight), and possbly some aero and I will start running over 996 cup cars

 

That's good to hear Joe. Glad you're seeing an improvement. The rear end wobble under braking is normal with an open diff. Once you install an LSD with a moderate 50-70lb preload that will be all gone. It will allow you to brake harder and later with much more confidence. Looks like our alignment set up is pretty much identical except you have more camber which the Hoosier like compared to the NT01s. I didn't realize you were running 550/600 rates before. That's pretty soft so I can see how you're seeing such an improvement with 800/1000. Chris in the process of figuring out my new rates but I'm thinking he will settle on 700/900 or 800/1000. I know he said he also wants to change my helper spring rates front to rear to really fine tune the way the springs unwind when the suspension is unloaded. I never really considered that but the idea is to have both front and rear springs unwind in unison. I'm thinking the helpers should be in the same ration as the mains, but what do I know? lol! I am currently running 175lb helpers front and rear. My Cup car uprights just came in today so they are going in next. Hopefully that'll complete the puzzle.

 

996GT3 Cup front upright jewelry.....

 

What is the advantage of the 996 cup uprights? Also, uprights are also known as wheel carriers, yes? Do the improve the geometry in a way that lowers the center?

Also, are the cup uprights compatible with your 996tt dampers? I don't think they would fit the gt2 uprights ( tt dampers have a larger diameter than the gt2 dampers)?

 

Yes, the geometry is all whacked with the TT uprights at the ride heights we are at which is approaching cup height. The TT uprights are designed for a 158mm front height and we are at 101mm. That's 2.25" lower than stock. The cup uprights lower the attachment point of everything correcting geometry, bumpsteer, etc. I'm no expert but it all makes sense to me.

Yes the GT3 upright are compatible with all Moton, JRZ, and Ohlins shocks. The shocks are the required diameter for the GT3/cup uprights for a direct bolt in. With the TT uprights an adapter sleeve is used on the shocks since the TT uprights have a bigger opening.