mikeb75's build thread

[mikeb75]

https://rumble.com/v35jsi0-20230804-fatt-session-3.html

After lunch - still dealing with heat issues; oil and water temps are good, but the intake charge air is high. Started playing with line through 3 and into 10 while continuing to short shift.

Unfortunately, the session got red flagged because a Porsche lost its brakes into T1 and found the tire barrier.

[mikeb75]

https://rumble.com/v35noyy-20230804-fatt-session-4.html

Last session of the day, I was feeling pretty tired and didn't want to push the car too hard. Ran some laps, called it a day about 1/2 way through the session.

818 is home in the garage, intact. I cleaned the gravel and grass out of it and other than the missing roof scoop it seems intact. Still need to check fluids, pads and wheel bearings. I did notice a tiny glistening at the passenger transmission output after the first session but didn't see any actual leaking fluid.

Printing a new version of the roof scoop, will fully duct the radiator inlet (the hood was rising a bit) and am looking at tunneling the turbo and exhaust to better isolate that heat from the engine compartment.

And of course, looking for my next track session!

[blomb11]

Nice work! I can’t wait to be able to get mine out on track. I am not sure if you have done this but wrapping your headers, exhaust, and adding a turbo blanket will help try to lower some engine bay temps. This has worked well on other Subaru engines I have been around and something I am working on myself. Plus like you mentioned ducting your radiator and any other heat exchangers you have will help them work better. I have to think with the coupe you might also look into ducting your intake since the engine bay gets so hot. You might even consider adding some other engine vents to pull air through the engine bay to exhaust the hot air.

[mikeb75]

I am not sure if you have done this but wrapping your headers, exhaust, and adding a turbo blanket will help try to lower some engine bay temps.

Already done, except the turbo blanket.

I have to think with the coupe you might also look into ducting your intake since the engine bay gets so hot. You might even consider adding some other engine vents to pull air through the engine bay to exhaust the hot air.

Yup! Intake is fed directly from the passenger side panel vent, which was enlarged. Once upon a time I had an aluminum airbox constructed that captured most of the incoming air and isolated the filter, I'm considering reimplementing that with an additional small outlet to a tunnel that houses the turbo and exhaust. Need to do some CAD work (cardboard, not computer) to see if it's practical.

Additional venting in the engine bay would probably be a good thing; I've looked at replacing the rear glass with a Lexan panel. If I really wanted to burn some money, I'd contract for a vacuum formed one with venting; but maybe I'll just go cheap and cut out some holes as a first attempt. But the rear hatch is right under the wing, so not sure how good it will be to disrupt that airflow...

I like how Gator's rear bumper cover came out after his mishap... might take inspiration from that also.

[FFRWRX]

Been driving mine around for a bit now and yes, the engine compartment does get hot. Hotter than I like. I added a small fan to one of the intake ducts from the roof, and cut away part of the trunk to give the exhaust more venting area. But now realize that stuff like that doesn't help much without a place for the hot air to get out. I'm looking at some sort of heat shield that helps direct heat from the exhaust out the rear grill. But I don't have much grill area directly behind most of the exhaust, so hot air really has no place to go. An additional grill beside the stock one is probably needed.

[lance corsi]

I made rear hatch louvers and am not using the hatch glass. In addition I made a mold for some acrylic side quarter window scoops.

[mikeb75]

I made rear hatch louvers and am not using the hatch glass. In addition I made a mold for some acrylic side quarter window scoops.

Would love to see pictures of that! If the roof scoop thing doesn't work out replacing the quarter windows with scoops was my next step.

[lance corsi]

Yep they look wicked cool. They are actually 2 piece scoops. One piece is the transition from the forward edge of the window opening and it extends just past the roll bar because there is a little bit of usable window that I didn’t want to block off, then the scoop starts where the first piece drops off and covers the entire quarter window opening. I cut off the flange area that the glass was supposed to glue onto, just leaving the rest in place in order to give enough lip to attach my small clips that bolt thru that area. I countersunk flat head screws into the acrylic scoop and this is what holds everything onto the roof. I used some .030” thick stainless to fabricate the clips. Stainless screws hold everything together. I have since decided to make some more scoops from cf in case/when the acrylic breaks, although I do like the old school look of the clear acrylic as it allows a view into the jewelry box! Pm me if you want pics because I don’t have any to put on this forum with the proper protocol. Maybe I could get Bob-n-Cincy to post them so everybody can have a peek.

[lance corsi]

Obviously I had to make a mold for each side. And in the process, the inconsistencies of the roof were revealed, so I’m not sure if my sizes would fit all roofs. Each scoop had to be carefully fitted to the window opening.

[Ajzride]

I've been working on 3D printing some scoops for the quarter windows as well, would love to see pics. I'll DM you so you can email them and I'll post on here.

[lance corsi]

Thanks Aj

[Ajzride]

Here are the pictures of Lance's body mods:

IMG_1954.jpg

IMG_2141.jpg

IMG_2171.jpg

IMG_2151.jpg

[J R Jones]

Air scoop function is complicated. Airflow is stratified and has varying energy. Laminar airflow is desired, but it does not exist on surfaces, especially deviant surfaces.
Dynamic air on the surface flows slower than air above the surface.
OTOH dynamic air does not want to turn easily and has force. In Mike's case the air coming off the windshield forced the air scoop up and off. Airflow does not stay attached over 7 degrees surface angle.
Highly developed aircraft (P51) and race cars (Mclaren) position air scoops off the surface for clean laminar flow, and no lift.
jim

P51 Scoop.png

McLaren620R_MSOR-Pack_00.jpg

[mikeb75]

Just so long as no one ever mistakes my 818 as a highly developed anything... but good to know. Since I'm reprinting the scoop, I'll try including a separation between the windshield and the inlet.

[Bob_n_Cincy]

Lance asked me to post these two pictures

IMG_2151.jpg IMG_2184.jpg

[lance corsi]

Just so long as no one ever mistakes my 818 as a highly developed anything... but good to know. Since I'm reprinting the scoop, I'll try including a separation between the windshield and the inlet.

Mike, copying is the most sincere form of flattery. Besides, it’s nearly impossible to come up with a truly original thing nowadays. We are all subliminally tainted in some way by the things we have seen in our lives. Very few original idea’s floating around. Besides, when a design has been proven to work, why change it? I like problem solving but I don’t regret using other peoples solutions.

[Ajzride]

You guys got me all motivate now. 107 degree heat.... damn the torpedos full speed ahead, I'm doing fiberglass work this Friday.

[mikeb75]

While working on creating a heat shroud for the turbo and exhaust I dropped a bolt on to the belly-pan/diffuser and into a puddle of transmission fluid. . Looks like the passenger side axle seal is weeping. So while I have that corner unbuttoned, guess I'll be replacing that... and maybe backing the diff preload a bit.

The plan:
20230818_180518.jpg
20230820_085340.jpg
20230819_173018.jpg

Aluminum chimney with some Thermo Tec heat barrier to try to isolate the turbo and exhaust a bit more and lower the heat soak on the intercooler. I printed an inlet or the passenger side scoop to duct some air to the turbo side, ideally blowing through the chimney and out the back.


The problem:
20230820_120039.jpg

Noticed a tiny weep after one of the track sessions... guess it was a bit more than that.

[mikeb75]

Replaced both transmission seals and after discussion with Andrewtech, tightened the sundials (passenger more than driver) to take some of the play out of the differential/bearings. It will have some affect on the pinion/ring gear spacing but should be safe enough. This adjustment firmed up the output stub axels so the seals actually work. After a few test loops it seems to be working, don't see any further leak from the transmission, so that's good.

Put a not-awesome updated roof scoop on the car, it's a bit ugly. Tried my hand at vacuum bagging the CF layup but there is at least one wrinkle, so no need to sand perfectly smooth and polish. If it works well enough I'll pull another mold and make a nicer part.

Finished the exhaust chimney, insulated it and finished the scoop in the passenger side vent. Definitely noticed less heat in the engine bay after a drive and the pre/post temp gauge looks better; won't know until I can really stress the car.

Looking for a late season track session opening so I can get more data...