GT750 Powered Race Car (D-Sports Racer)

[sav0r]

Keep in mind the lap record is a 2:09 or something like that. A two minute lap time in modern racing is big, Le Mans being perhaps the standout with 3:15 laps, but most of it is just straights. This street circuit is almost all turns.

[sav0r]

We got the spool welded up yesterday. What an ugly old bastard this thing is. There is massive force on this thing as a result of chain pull which is why it failed three or four times before this one. The single inboard rear brake also hangs on this thing, so I guess it gets punished doubly. It's one of the more challenging engineering parts on the car. The grade of aluminum certainly has been degraded due to being welded on like 12 times, so we decided to go one step further this round. We made a make shift oven out of oven bricks we had laying around as a result of us building an earth oven. Using some torches we heated the spool to around 1000F for about 40 minutes, then quenched it. It will age naturally for 3 days then it goes in the real oven (yep, the one the kitchen) at 425F for 24 hours. Hopefully this restores the temper.  While were at it, I modeled the entire the entire setup and will be prepared to machine one out of billet. Probably a bolted plate situation but I am not worried about it now.



We finished the new half shafts too. That was kind of fun. We had the half shafts in the lathe, with the lathe well covered in wet rags to protect it from splatter, we got the ends nice and true with the new collars in the middle, then Dave zapped them with the MIG machine while I manually turned the lathe in some attempt to match the weld speed as the beads went down. They actually turned out great, but that was a bit of a new process for us. Unfortunately I didn't take any photos. After they were welded we cleaned them with the lathe. They look great! The beads are massive compared to the old setup, looking good!

Dave also went all in on rod ends. Nearly $500 worth for the rear of the car, and we aren't even replacing all of them. Trailing link suspension really is a pain in the ass. That said, the rear steer issue should be gone. If we have a bump steer issue it is going to get worse... We have a month to go on prep, we will probably spend several days just going over rear geometry.

The Kurbside is basically functional. Dave got the windows in, then took them out, then started messing with the windshield wipers again. It looks exactly as it does in the previous photo. However, the remote adjustable mirrors are now mounted and working. lol. All it needs to do is tow the trailer 100 miles. Fingers crossed.

[sav0r]

I wish I had grabbed a photo of the spool setup from the opposite side. It's hard to tell what is going on there. That fabricated box is completely hollow. The axle runs through the center and accommodates the sprocket, chain tensioning parts, rear brake, and all the half shaft bits. It all swings on the top pivot (show in picture) and has two links that are adjustable at the bottom to tension the chain. The broken section is where you can see the bit of grinding, although the crack extended to the side not seen in the photo.

I spoke to my father on the phone today and he figured the car is worth about $400 in scrap. He's not sure if he should turn it in or not. lol. It's hard to get a read on peoples sense of humor on the internet, but that is definitely him joking around.

[sav0r]

Well, we are two weeks out and are basically ready to go.

We ended up replacing a ton of the rear rod ends. It is way better. We various modifications and adjustments, but the car went on the pad and scaled out basically perfect without much messing around. The van is together, it tows the trailer. We have a few issues with the lights. The rights don't work at all on the trailer when connected, the lets are fine. Probably a plug issue.

Pictures of the car on the "pad", the new tow setup, inline rads, and some puppers along the way;

[pidjones]

So, which one is the engine tuner, and which the chassis expert? This looks like so much fun! Hope it holds together well and brings home some trophies for you.

[sav0r]

Both are experts in eating leftovers and getting spoiled, not much else.

This year we are hoping the car doesn't break every session. We have picked through so many of the little hang ups, but every time we go faster we find another weak point. I honestly might just baby the thing through the first three sessions and then give it hard thrashing in the race and hope for the best.

We ran a pressure test on the engine yesterday, all good there. We let it idle for an hour, once the thermostat cracked at 210F and the rads warmed, it then sat at 170F for a good 40 minutes. No leaks, no drips, and when we popped the cap it was pressurized still. I think we might have the cooling issues worked out with the bigger impeller and extra rads. That is certainly the coolest the engine has been especially considering there is no active cooling, it relies on being driven to force air through the cooling. With some luck we might have finally got the cooling efficiency to where it needs to be.

[sav0r]

I didn't grab any photos, but there isn't much of interest to see.

I spent a good part of the day cleaning the car. My father worked on tires prepping them for treatment. The car looks just about as good as a 45 year old car that we have tried pretty hard to keep reasonably original lol.

The car is in great shape mechanically. I think the best prepped it has ever been. Which of course is always the goal, but time, money, focus, willpower, it all varies. We did a nice job this year. It is a shame we never got on track beforehand, but we took our knowledge from the last few years and got it together. There has been many changes, most of them refinements. The development while slow and tedious is about right. I have a good feeling about this one.

We load in on Friday. I will grab photos and be back to report in.

[pidjones]

Refinements is where I like  to see things change. It isn't often (you have to be way off) that a "swing for the fence" change works out. Often just a small change makes a big difference. Important for reliability, as it is an indication that things are staying pretty close to where you set them.

[sav0r]

I agree. Progress is incremental usually. It is hard to be a revolutionary.

Everything is officially in order for the race. As usual, I got a talking to before the race even starts.

Every single year there is some hang up with my entry by the governing board. The guy who runs the organization really does not like me. I've only met a few of the members here on this board in real life, but I would consider myself a pretty fun and loving person. I'm not mean or malicious, I just like to race.

I got an email on Monday from the governing board that my license and medical evaluation weren't valid. I hold an SCCA Pro license, with a medical evaluation that is good until 2024. That information was submitted with my entry. If you aren't familiar with car racing licensing, an SCCA Pro license is basically the king of licenses in North America. It works in Canada, it works in Central and South America, the only license that would be better is an FIA License. North America doesn't really use the FIA so there's no need for it. Though at one time I carried an FIA license. I could enter a 1000hp TransAm car and nobody would question my license. It is basically a passport to drive in any race. The exception being the Indy 500.

After two days of emails and phone calls they have finally, officially, allowed my entry into the race. Mind you the entry fee was already paid. They have said that my license will be accepted this year, but next year I need to buy their license. For a total fee of $25... paid by check only. Sigh.

I have had my SCCA Pro license since 2009, it was totally acceptable to use it for entry into the PVGP since my first entry in 2015. This year, the highest license in North America isn't good enough, but they let me slide.

I can only laugh about it. There is just nothing else I can do.

[sav0r]

accidental double post on this.

[pidjones]

Sounds like they are bucking to be FIA regulators.

[sav0r]

I don't know if it is that they just genuinely have it out for me for some unknown reason, or if they just like to hassle people to gain some sort of power or ego boost? It is completely ridiculous though. We are racing cars for charity, my licensing far exceeds what I need for the event, and on top of that this is my 6th year competing in the event.

[sav0r]

We made it! The car is there, the pit spot is setup, the brakes are bled, the engine starts. The clutch was iffy getting down to the parade, but it works well enough to ride around town. In the last photo you can see a yellow Porsche convertible top right. Poor guy got stuck behind me in the parade. Suffice it to say, my car loaded up early in the drive, he got the full 2t treatment.

Lou rode in the passenger seat (aka the space for the fuel cell and fire bottle) down the to the parade. At first he was completely terrified, then after a bit he loved it. The streets get lined with people that wave. There are police at the intersections. He got waved and enjoyed the race car experience for his first time.

[sav0r]

Well, we came, we saw, we didn't quite conquer.

We finished the first two sessions of the weekend. Whereas last year we never finished a session. A huge improvement. The first session we used as a shake down really. I eased everything up to temp and tried to watch temps and get a feel for the news brakes. The second session being qualifying, a clip fell off the needle and I was left with a pretty poor running engine as a result. Though I decided to continue on as to get some more seat time. It was an easy fix. We qualified in the back half of the field but with plenty of pace left on the table. The unfortunate thing is that I haven't had seat time this year and I could have really used that session.

On top of that, there was a huge storm that knocked down some trees and a telephone poles that evening. So they cancelled the Sunday warm up. That left just the race to get into the swing of things. Of course it was 95F, first real track time of the weekend and I had to drive the thing at some reasonable pace.

I got a nice start and moved up a few spots. By the end of the lap I managed to gain one more spot. Then I think one guy ahead me retired. I was starting to pick up the pace and passed one other guy. By this point the top two were long gone but I was third. I got a little pressure from behind but was gaining pace as my comfort grew. It was around lap 4 or 5, now about 15 minutes into the race, I was starting have some issues with front lock ups. So I dialed in some more rear bias. About one lap later the brake pedal went to the floor, I damn near crashed into the Jersey barrier on the exit of turn 1 but I collected it up.

I decided to carry on at a significantly reduced pace. Any finish is better than a DNF. As I cruised brake pressure slowly started to return. Water temp was high, but manageable. The nearby 4th place car then dropped out with a mechanical and I knew I had a massive gap behind so I really started babying it. Unfortunately on lap 9 the fuse on the ignition blew leaving me dead in the water, another podium lost. They completed 14 laps total. We aren't sure where the issue is, but obviously the fuse didn't blow because it was hot out.

There are a few takeaways here. 1) we are really close on cooling, it was marginal but functional. 2) more work on the brakes, probably a change in the rear brakes this time. A vented rotor and some sort of cooling. But also cooling for the fronts. 3) get rid of the fuse block, if the wires burn they burn. 4) a test session or two and some new tires for next year are needed. 5) figure out the cooling on the Van.

I think the car might have a bad damper as well, but we didn't investigate. I'd like to go to a new set of dampers, but Dave wants the Ikons.

Finally, my camera didn't record so I didn't any on track video. Pretty bummed about that. Luckily the track was rather slow this year. So it isn't really comparable to other years, nobody got within 3 seconds of their personal bests. It was too hot, to greasy.

Anyways, this will probably be the last update for a while. My father is completely burnt out, I am pretty burnt out, and we both need to mow our lawns and do work that pertains to everyday life.

Once I get my photos sorted I'll post if there is anything worth seeing.

[Clem710]

Glad to see you finally got some quality seat time, it was a tough weekend to be racing. 

That track is always going to be hard on brakes and cooling systems, lots of elevation and stop and go. 95 degrees doesnt help either.  Might need to do things differently just for that track.

Good luck finding the short, hopefully its not in an expensive place.  You'll find it, there cant be too many wires on that thing:)

Heat may have been a factor if you are running points and the primary is on the stator, wires and coils only like to be so hot and vintage enamel might melt when the motor is really soaked out.  You being water cooled makes me think its unlikely but I dont know those engines at all, I'm sure it wasnt cool behind the flywheel Sunday.