docwyte

Got the car out on the track this weekend for the first time this season.

Over the winter I did a cam swap and retune (372.4rwhp, 360ft lbs), added an adjustable rear brake proportioning valve and tied up a bunch of loose ends.

Over all the track sessions went well. I was able to figure out what position the brake proportioning valve needed to go in, with a minimal amount of sphincter tightening moments! Brake oversteer is fun, M'kay? Not so much!

Motor ran really well and was consistent in power. I had to add some fluids (coolant and oil), but the coolant levels stabilized and I didn't need to add any more. I ran 8 sessions and added maybe 1.5 quarts of oil, so not too bad there.

I'm keeping an eye on the coolant level, I may have a leak somewhere, but it isn't evident. Nothing on the ground and no crustiness anywhere in the engine bay. We'll see...

Also keeping a close eye on oil and coolant temps. It wasn't a very hot weekend, around 70 degrees. My oil temps were around 230-240F, coolant temps pretty close to that. The American Iron (camaro/firebird) racers are telling me my oil temps are in range, but coolants temps are high.

I'm running the stock 951 radiator, I'm thinking that's the issue as it's probably 20+ years old. Are there "upgraded" larger radiators available that don't cost an arm and a leg?

If not, I'll just go with a new factory radiator, I'm sure that'll be much better than a 20 year old one! Ironically that's one of the few remaining parts on the car that I haven't changed yet...

Car pulled like a freight train! I was easily hitting redline in 4th gear on the back straight, showing 135 mph. More is there if I get a better launch onto the straight and I'm not such a wimp going into the braking zone.

I need to work on my corner speed and not hitting the brakes as hard. I was too timid in both those respects as I didn't have confidence in the brake bias early on and this is the track I'm least comfortable on. (High Plains Raceway)

Car sounds awesome! Big time V8 acceleration noises and pops and burbles on decel. Plus it shoots fire ***** out the tailpipes! All the other racers in my group commented on it.

I turned a 2:08, I know I can do a 2:04 once I get it all together. All was well until I packed up and left the track.

That's when I noticed my check engine light was on. Motor was still running fine, so it's probably something stupid and I ignored it. Got home and stupidly decided to try to back my car with tire trailer up into my driveway.

This is something I usually never attempt to do as the trailer is so short it's hard to control and very easy to jack knife it. I usually pull up in front of my driveway, un hitch the trailer and push it into my garage.

Well, a moment of inattention was all it took as I was backing the trailer up and unbeknownst to me it'd jack knifed and I ended up backing my car up into the trailer!

Ended up denting the drivers third quarter panel, (below the fender character line luckily) as well as punching a hole in it!

DAMN IT! All my fault too, so no one to blame.

Guess it's hitting the body shop now. Only bright spot is I can have them repaint the drivers front fender, as the clear coat is peeling on it and the color match is off courtesy of a repair done to it before I got the car. Depending on how much the repair costs I may go with 968 mirrors too, as I can just get the body shop to install them.

Tedro951

Congrats on getting the car to 99%. Sorry to hear about the crunch, but thats Karma.... All that time under the hood made the body jealous!

I'm with you on the rad. Stock is cheaper, and if it doesn't drop the temps, it would probably be easy to sell without losing much.

Hopefully its just a sensor wire or something throwing the code. This may sound dumb, but how do you pull the codes on the LS conversion? Is the OBD port swapped? I'm an idiot on this...

pudges951

Sounds like a beast. Get some video of it on ur next track session if you can.

arthropraxis

How are your fans set up, through the PCM or using the Porsche fan control in the radiator and relay? Not that it makes a difference, I am trying to make a decision on that bit of wiring. I am leaning to the PCM but the wiring will be more time consuming.

docwyte

I brought over the OBD2 plug and have a light, so I can just plug into the port and read all the codes.

Arthro, not sure how Eric wired it up, best to ask him how he does it.

User 52121

Did you ever run this track as a 4cyl? How do your times compare?

docwyte

I did, but only when the motor was blowing through oil faster than you or I can drink water, so the comparison isn't valid...

Van

There's a summit racing radiator that's a pretty close fit... I don't recall the p/n, but I read about it in Greg Sloan's conversion manual.

eclou

My LS1 944 got to go on its inaugural track run today. Open track event was scheduled today but I only got to run 1 hour because of work. The one hour I got to run was one continuous hour though. I saw absolutely no issues with the powertrain. Airtemps were 85F and my water temps ran only 200-210F, Oil temps to 230-240F. No heat soaking issues, no powersteering overheating, etc.

The power was deceiving - I was used to riding the boost curve of the 944, but this car keeps going. The old turbo 4 would run out of steam and adding throttle gained very little. On this motor the throttle adds more unexpected power. Very pleased and I can't wait to get back out there.

docwyte

How new is your radiator gene? You're not running ac, right?

eclou

radiator is 25 years old. No a/c correct. I don't think an a/c coil would make a 30 deg difference though

marc a

On the OE radiator the fans can actually impede flow if they come on when at track speed. I have the Don Davis radiator with a switch to turn on the fan if I'm waiting on grid or cooling after a session.

How did you address the coolant path that goes through the throttle body? If you did a bypass and tapped into the coolant take return line then the engine will self purge. If not then you have to make sure you got all of the air out of the system (kinda like our turbo motors).

The main thing on this conversions whether running the OE radiator or a V8 radiator is make sure that shrouding keeps the air going through the radiator rather than around it.

I can get the Don Davis part # if you are interested, although it's probably on the Wiki here:http://944hybrids.pbworks.com/w/page/1147189/FrontPage

I have had my conversion since '07 and have addressed just about every issue so if I can help, let me know.

Here is my track appliance: http://www.porschehybrids.com/gallery/951ls1

Good luck and have fun.

docwyte

Hmmm, same shop built my car and Eclou's car. Shrouding should be the same, pretty similar motor set ups as well.

I am up at altitude and I am running AC.

Your comment on air in the system has me thinking though, as I've been having to add coolant to the system with no discernable leak. I'm wondering if the system has been burping and that's why I've been having to add coolant.

The last few sessions on the track coolant levels stayed constant.

Regardless, my coolant temps were markedly higher than Eclou's, on a cooler day, but at much higher altitude.

If you could get me the part # for that don davis radiator I'd appreciate it!

marc a

The system has probably purged by now if the coolant level has stabilized. Shrouding is really the key, although the elevation is probably a factor. Try using a bottle of WaterWetter in the system.

Couldn't find anything but RH 4945 on the radiator. The "RH" stands for Renegade Hybrids because "RON" Davis (not Don) makes the radiators for RH. Call Ron Davis Racing Products @ 623-877-5000 and they should be able to help you. The dimensions are: 23.75 x 16 (2.75 core); however they should be familiar with the radiator.

Sorry I couldn't be of more help.

docwyte

One of the local Camaro racers chimed in and was running the same exact temps as I am now running the same weight oil I am now (synthetic 5w30). He said when he ran straight 50 weight racing oil, along with just water and water wetter his temps were much, much lower.

So that kinda has me thinking that maybe I shouldn't run "regular" street oil in the car on the track. Rennlist wisdom says???