First shakedown at VIR this past weekend

I haven't been very active as a poster here but I have used this site quite extensively as a resource.  So let me start off by saying many, many thanks.

Back in December I decided to start my LS2 swap.  Finished the conversion early March; the entire swap probably took me two solid months of hard, dedicated work (with a break during the month of Jan due to backordered parts).  It helped that my wife was out of the country for the month of Feb, which enabled me to pretend I was a bachelor.

Car is a 1986 951 track car that is technically still street legal.  Used a 2006 LS2 with the DBW throttle on purpose; it enabled me to run an AIM dash and tap right into the CAN bus (see pic below).  Engine has a modest cam (a modified version of the GMPP ASA cam with a more linear power band), Kooks longtubes, aluminum flywheel, and underdrive pulley.  



Anyway, this past weekend I drove the piss out of the car at VIR for the first time.  The very first session out, I equaled my fastest time with the turbo motor.  Then proceeded to knock another 7 seconds off that throughout the course of the weekend...and that was still pussyfooting.  

The only issue I experienced was insufficient brakes, which I knew was going to be a problem -- so I would only get ~8 laps before they overheated.  But I'm not joking when I say it was the ONLY issue.  The car was extraordinary.  

Max oil temps were 208F, though that was the hottest session.  The rest of the weekend was down in the 190's (it was a cool weekend).  Water temps were perfect at 195F the WHOLE DURN TIME.  Oil consumption was modest: 2/3 qt for the whole weekend (seems high-ish).  No smoke or anything, according to other drivers.


For brakes I went the Tilton dual master cylinder route.  Pedal feel was good -- very similar to stock, but then again I have never liked stock 951 brakes.  I'll be upgrading my calipers/rotors next so it'll give me a chance to resize my front MC to make things a bit stiffer.


Finally, didn't get any share-worthy video from the weekend but here's a video of the first start, taken end of Feb.  The end of the video gives a good idea what the cam sounds like.



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Nice build! After 2 warmup laps at NJMP Thunderbolt, i accelerated out of the 1st double apex and knew at that moment the swap was totally worth it .

Were your brake pads not up to the task?

Thanks! Very pleased.

And yeah, it's more the combination of pads, rotors, and calipers. They were problematic with the previous engine so I knew this was going to be an issue.

As of right now I'm thinking I'll upgrade to some 996TT calipers and take advantage of some 320 or 330mm rotors.

As of right now I'm thinking I'll upgrade to some 996TT calipers and take advantage of some 320 or 330mm rotors.

Great minds think alike... I have the 4 piston 996tt brembos with the cayenne 13" rotor.

Evidently the 6 piston caliper from the 996tt will fit your wheel...

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Very cool. Boy, the 6-pots sure would be something eh?

I've been going back and forth with the guy from Tilton to determine the best size for my MC's with the upgrade. As they were, they felt pretty damn stock (5/8" front, 3/4" rear with a motion ratio of 6.2:1). I didn't like the amount of travel though; I'd like a firmer pedal. So it's looking like 3/4" front and 13/16" rear is what I'm looking for to get a firmer pedal (albeit requiring a bit more foot effort). We'll see.

car looks great, very clean engine compartment !

I never had a brake issue using standard Turbo S brakes, but the rotors would only last 1 season. I went to Big Reds and 965 front rotors and get 2-3 seasons out of them. I do have brake ducting directly to the center of the rotors

docwyte wrote:I never had a brake issue using standard Turbo S brakes, but the rotors would only last 1 season.  I went to Big Reds and 965 front rotors and get 2-3 seasons out of them.  I do have brake ducting directly to the center of the rotors

Yeah, I had standard '86 calipers with slotted rotors and PFC08/11 pads. I do have hoses (as well as bargeboards I made which fit on the control arm to help direct air).


And thanks hutch! I overheard huge praise this past weekend: there happened to be another LS swap car (an E36 M3) and he was talking with the tech inspection guys. They said, "Hey, did you see there was a 944 with a V8 in it? Looks like the factory did it."

Now if that's not high praise I don't know what is. Ok, done bragging (for now).

I've been running Hawk DTC70's up front and Pagid Blacks in the back.

Big difference between the stock Turbo S brakes and the regular 951 ones, my rear brake calipers are the same as your fronts...

Car looks great. Two part question, Do you have manual steering and do you like that steering wheel?

racertomtom wrote:Car looks great. Two part question, Do you have manual steering and do you like that steering wheel?

Thanks. Yes it is a manual rack -- the 015 sport version. Last season I cleaned, regreased, and rebuilt it -- muuuuch better. Due to clearance issues with the headers, I had to buy a new power steering intermediate shaft and modify it; it's nice to have tight U-joints again!

Yeah, the steering wheel is fine. Diameter is great and it looks neat but I don't care for the suede -- causes more problems than it solves. Need to keep it scuffed because once it gets greasy and matted it'll become more slick than a standard leather wheel. The thickness of the rim could be a little beefier, too. I'm thinking of recovering over the suede -- this should solve both problems simultaneously.

The car looks great - very clean build! I found the climbing esses at VIR to be very interesting with the speeds the LS motor could generate!

Well, I won't be bringing my car to the track this weekend -- will be there to instruct, however.

Realized a bad cam sensor was what was causing me to run so rich. In trying to remove it, it literally disintegrated -- and promptly fell inside my cover (well, not completely inside). In other words, can't remove it from the outside....no matter how awesome my pliers happen to be.

So guess this means I get to tear the entire front end of the car down again.