ddombrowski

So rather than start a new thread for each race we complete, I thought I'd keep a running log of our progress with our 944 budget endurance racer.

You can see our previous entires for sebring and daytona in the links below:

Starting a few months back, we ran the car in the 14 hour Chumpcar race at Sebring raceway in September of 2016. We came out of the Daytona race with a few issues and worked towards addressing them for this race.

1 - We felt the stock oil/water interchange cooler was not adequate for Florida racing and sourced a turbo oil cooler and block adapter. Early testing showed that while the oil ended up running a little hotter, the water temperature was much reduced and we considered this a huge success. Prior to the separate cooler, water temps were reaching 220-230 on track and heat soaking up to 240 (and overflowing the expansion tank) on pit stops. We installed a small electric fan, but its usefulness is limited as the electrical system needs to be shut off for pit stops anyway.

2 - We have always known our corner weights were off a bit, and finally took some steps to address this with adjustment of the rear spring plates. While it definitely helped, the weights are still off as the frame is slightly tweaked from a collision in a prior life. Regardless, the improvement from our first corrections were substantial, hopefully some day we can adjust out the rest of the weight. This allows us to get heavier on the brakes without locking tires.

3 - We have the tall 5th gear, which offers nothing on the long straightaways. We did not get a chance to swap this out before sebring.



So we were off to a good race start in the morning as our first driver took the car out. Just before the first hour, he radios in that he spun the car and that the steering doesn't feel right, but he's not sure what the issue is. At the first pit stop, I take over the car and while the steering is super stiff and doesn't want to unwind, I also can't pinpoint what the issue is. It still turns properly, and nothing was stuck, and the car still handled well. The steering wheel was just tough to turn. We decide to just keep driving, eventually it will really break and we'll fix it then.



I turned some decent times and then handed the car over to the 3rd driver, then the 4th. Our other two drivers notice the stiff steering but it doesn't stop them from turning quality laps. Otherwise, the car is running pretty well.




We do our second rotation of drivers and I think by this time all of our drivers, myself included, put down personal bests in this car at Sebring. We steadily climb in position, mostly due to attrition of other cars having to spend time in the pits.



Sometime in the afternoon, I notice that the car is making a noise intermittently from the right front on hard lefts. It sounds like a wheel bearing. We got our spare bearings out in case we needed to change them but decided to continue running the car unless the noise got particularly bad.



Rain came in the afternoon, and before anyone had any time to get sideways in the rain they red flagged us for lightning. Cue about 3 hours of standing in the pits, trying to stay dry, and scrambling to cover all the gear. After a long wait, they finally clear us to go back out, but we have to go back out with the driver that was in the car when it came in. By this time, the track is wet and its dark. We keep that driver out for a few laps and then come up with a final driver lineup for the finish.



I took the last session and by that time the bearing noise was starting to get louder. I spent the last 15 minutes in the car going pretty easy on it hoping it didn't get more serious as I really wanted to give my team a finish at Sebring. Around 11 at night, we took the checkered at Sebring, which was an awesome feeling after our clutch failure there last year.





We finished 38th out of around 90 cars, which I'm pretty happy with. We drove the car back up on the trailer at the end of the day, which I was also particularly happy about. Overall, we had the wheel bearing wear out, the steering rack had failed, and one of the control arm ball joints had play in it, but nothing serious. Oil temps stayed below 230 and sat at 210-220 most of the time, a big improvement from Daytona.

We had a few months to prep for sebring again in december. We replaced both front wheel bearings (not too difficult, probably should have been done before we started racing), rebuilt the control arms with rennbay's kit, and swapped in our spare steering rack (and then fixed the old one).

We ran at Sebring again on New Year's Eve, and when we get some photos back I will write up another recap for that event and post it here.

924srr27l

Great accomplishment, Well done.


What's the scoup with the removal of the side and rear windows,
Does this not play havoc with the aero and cause drag?


R

Paddy

Well done!

Wheels bearings are a must and you might want to consider changing to the early steal arms and have two spares in the trailer. Super easy and cheap to replace. We also ditched our power steering to take one more system that could fail off the car and installed a manual rack.

I'd consider adding an additional oil cooler. I added a huge cooler in the front nose panel of the car for the 24 hour races at VIR in August. Without that we were seeing 255-260 oil temps in the sump with all new water cooling system- rad, hoses, pump.

924srr27l, you have to remove all glass from the car except for windshield. It does mess with aero a bit, we've since added lexan rear hatch and side windows with ducts. Not the best photo, but pic of the lexan.

Van

It's hard to tell from the pictures, but I think your hood vents are on backwards...

JustinL

WCMA? Where is this car from?

Paddy

Agreed, I think the vents are backward.

Justin, I bought the windows from a nice guy in Canada, car is kept in Virginia.

Paddy

We also added a turbo transaxle oil cooler.

ddombrowski

Let me see if I can dig up another picture. I am fairly certain that the openings point backwards (towards the windshield), but it does really look from the photos like they point forwards.

Regardless, we bought the car with those vents on. The previous owners of this car had a few other questionable configurations. Oh well. I don't think they took it that seriously.

ddombrowski

We've been down that road. We considered changing them, but it would require changing the struts, hubs, and tie rod ends to early offset. On top of that, we'd have to do the same thing to the rear unless we want to run mis-matched offsets or have different wheels (early/late offset) front/rear.

If we were an 85.5 with early offset aluminum arms, then yeah, I'd change to steel. In this case, its easier jsut to rebuild them. Besides, we found a fairly decent set of late aluminum arms out of the junkyard for $25 each. They're not great, but they'll do in a pinch.


Is this with the 'stock' turbo oil cooler, or is this with the stock NA oil/water interchange cooler?

We never measured oil temps separately in the sump until we got our oil cooler, but since then, we've never seen higher than 235-ish and thats running in Florida in the summer (although we've never done an endurance race in august).

A lexan hatch is next on the list before Daytona. I wish there were some tutorials out there, all I've managed to source is a few pictures here and there of the process of placing the lexan on the frame of the old hatch.

Did you all buy your lexan pre-formed? Is it a pointless endeavor to try to buy bulk lexan and form it ourselves with a heat gun? My gut feeling is to just buy the pre-formed piece.

Paddy

I hear you. Our car was was kind of a franken car I bought from Jeff in New Jersey, but came with 86 turbo strut housings so the conversion was pretty easy for us. We also have turbo brakes and have had to play around with proportion valves to keep the rear from locking up.

We're running a 951 oil cooler housing plumbed into a Mocal cooler.

Buy the preformed and save yourself the headache. Apex performance sells them and it's worth the extra cost.

You should come do the 24 at VIR this August!

ddombrowski

I meant before that, when you said your oil temps were exceeding 265? Did you have any oil cooler at all then, or was that the stock NA setup?

I will look into Apex for the lexan. I don't see it on their website, but I will give them a call.

I would love to do a 24 hour race someday. Right now, we only have 4 drivers and 2 pit crew so we'd probably have to grow a bit to make it feasible.

Paddy

Those oil temps were with the stock cooler. Things are much better with the 951 unit.

Yeah, you need at least 4 drivers and 4 crew for the 24hr.

ddombrowski

I finally checked the hood vents. Looks like they point aft like they should. The other pictures must just be an odd camera effect because they do look like they're on the wrong way in some. Weird.

PPo

Hey guys,

Just wanted to put our hand up as another front engine waserpumper ChumpCar team. We run a red 924S under the name High Maintenance Racing. Based out of Toronto, Canada. We entered 4 races last year, 2 Calabogie, and 2 Mosport. Currently replacing... well... almost everything!

We went with poly rear and side windows. Without the hatch, we found too much exhaust would enter the car making us a bit dizzy. But I guess the exhaust makes you just crazy enough to make you want to keep racing.

If I where to purchase another poly window, I would probably try these guys -> http://www.fivestarbodies.com/store/...product&id=485

We are planning some US races this year, thinking about the 24H at VIR for sure... perhaps we will see some of you guys there!

P

PPo

Also, we may add hood vents... but use floor vents from Home Depot.

Good advice on the oil cooler. It's something we are thinking about, but contemplating the impact of introducing more possible failure points, we are being careful of how we cool the engine with airflow as well. We will think about it...