Time Trial Build Thread (aero, widebody, any other nonsense)

[truegearhead]

Originally Posted by Van914

truegearhead,
you might like this too:
https://rennlist.com/forums/porsche-cayman-and-cayman-s-all-generations/1211154-cup-suspension-on-a-cayman.html

Wow super similar widebody design that he’s working on right now. That’s a dream build. Definitely working with a different budget...

[truegearhead]

Progress continues, I'll post later on the hardware progress. In the meantime I've tackled the gauge problem. The stand alone computer won't be able to talk to the Porsche gauges so I made a digital dash using realdash and an iPad that sits behind the factory cluster. Checkout the youtube link below of it in action

Video of the gauge in action
https://youtu.be/xPJ0kvIynyk

[Racer Boy]

Wow, that's awesome!

[804_boxster]

This is such an awesome build, do you ever bring it to c&c?

[truegearhead]

Originally Posted by 804_boxster

This is such an awesome build, do you ever bring it to c&c?

Thanks! Pre-covid I was normally there with my 911 but I plan on bringing the Boxster this summer (maybe on a trailer, I’ll be that guy). Let me know when you’re going on all I’ll meet you there if I’m not on baby duty (or if I am on baby duty and have finally have replaced my non-baby friendly straight pipes on the 911).

[truegearhead]

More turbo goodies are arriving, all the fuel system parts are in but I'm still waiting on the Turbos to arrive (next week hopefully) and the final intercooler is backordered so who knows. Last night I got the coolant system roughed in and cut some more of the body panels that hide underneath the aluminum widebody (this also makes room for the intercoolers that will sit just in front of the rear wheels). I have cut out a tremendous amount of steel so far, I'm hoping with the V8 and the twin turbo system (which is probably 130lbs) I'll still be under 2500lbs. At a minimum the weight balance is going to off. This weekend I'll throw the fuel system in, button up the coolant system and build at least one new wheel well to accommodate the 8" wider body and new 12" wide rear wheels, I'm going to cut out all the steel from the wheel wells, it'll all be aluminum. I have a feeling I'm going to end up with just the frame rails and a tubular steel rear frame here soon. more to come later

[JayG]

Definitely a FrankenBoxster
Very cool!!!!!

[1thenaton1]

Damn, just catching up on this, epic build!

Don't see many details re the engine swap. Which Audi V8 did you go with? What turbos? What management? I imagine you are also upgrading internals on the engine before going forced induction?

[truegearhead]

Originally Posted by 1thenaton1

Damn, just catching up on this, epic build!

Don't see many details re the engine swap. Which Audi V8 did you go with? What turbos? What management? I imagine you are also upgrading internals on the engine before going forced induction?

Engine: I’ve changed up the engine three times, sent one engine back and still have another sitting around but settled on an Audi ABZ 4.2l V8 which if I hadn’t already changed my mind so many times I would have moved onto a different platform. The ABZ bolts up to the Boxster trans which is nice but the real benefit is that it’s an incredibly short motor (same length as the Boxster flat 6 so it actually allows the trans to sit in the factory location. With the trans in the factory location you don’t have weird drive axle angles which is a big problem on a track car. The problem with the motor (I now know) is that forged internals are all NLA so for now it’ll be stock. People run stock internals up to 1,000hp so I don’t think my goal of half that will be a problem...we’ll see.

Engine management: I’ve also changed this up three times too starting with a reflashed stock Audi ecu, then mega squirt which I just sent back, now I’m waiting on a VEMs ecu which is being baseline tuned for my setup and they’re making a harness for me (totally plug and play besides three wires to connect to the boxster..how cool is that!). The companies called EFI Express, awesome guys!

Turbo’s: I just received the turbos this weekend. I ordered the smallest S200SX-E turbos they sold from Borg Warner but they shipped me the largest S200SX-Es so I’m not sure if I’ll return them or change my approach a bit. I’m targeting 520hp for now at 8psi. If I can find internals (or have them made) the turbo, fuel and cooling setup will take the engine to 800hp. I hope Im never stupid enough to try that.

[Quadcammer]

you are gonna run the stock 5 speed with 520hp?

How many do you plan to replace per event?

[truegearhead]

Originally Posted by Quadcammer

you are gonna run the stock 5 speed with 520hp?

How many do you plan to replace per event?

I'm hoping easy shifting and no launches and a cooler will get me through an event or so, I'm sourcing an S transmission to replace it.

I have a feeling this whole thing is going to look like the BluesMobile in the final scene. But hey...we’ll see. At a minimum you all will get a good laugh when everything explodes.

[truegearhead]

Turbos are bolted on! They just fit below the trunk lid, next I'll need to get the charge pipes fab'ed up, the waste gates installed and then wiring and oil plumbing. Soooo much work to do, I feel like I've gone off the deep end with this project

[truegearhead]

Oops looks like I posted the same photo twice, here's the correct one

[78F350]

It's all awesome! I think it may be about time to change your signature:

1997 2.5 Boxster NASA Time Trial track car
2003 911 C2
NASA HPDE Instructor

I was talking with one of the GRM guys in person (pretty sure that it was 'Stafford1500') about boost with the Audi 4.2s. He mentioned changing the head gasket to adjust the compression. I don't remember the details, but I think that he recommended a thicker gasket to slightly reduce the compression. If you are boosting a stock 4.2 now, you may want to look into that for when you build up the replacement engine.

There may be a few guys on the AudiWorld Forums that have the forged internals tucked away. "audinutt" offered me a set about three years ago, but at the time I didn't plan to tear down an engine. It may be worth asking. If they see your build they will probably be happy to help out.

[truegearhead]

Originally Posted by 78F350

It's all awesome! I think it may be about time to change your signature:



I was talking with one of the GRM guys in person (pretty sure that it was 'Stafford1500') about boost with the Audi 4.2s. He mentioned changing the head gasket to adjust the compression. I don't remember the details, but I think that he recommended a thicker gasket to slightly reduce the compression. If you are boosting a stock 4.2 now, you may want to look into that for when you build up the replacement engine.

There may be a few guys on the AudiWorld Forums that have the forged internals tucked away. "audinutt" offered me a set about three years ago, but at the time I didn't plan to tear down an engine. It may be worth asking. If they see your build they will probably be happy to help out.

This is one of the reasons I went to e85, e85 has almost 3 times the evaporative cooling and reduces the detonation for high compression motors so there's no need to reduce compression. I also had EFI Express put the whole plan together, they have a tremendous amount of knowledge turo'ing these motors so I basically just returned everything I bought and bought their recommended setup.

Thanks for letting me know about the forged internals tucked away! I'm reaching out to them right now and will report back.

[truegearhead]

I'm super concerned about heat on this car so I've gone a bit overboard on a few things including these intercoolers. I've instructed a lot of students that had turbo cars, and almost all of them (including the factory turbo'ed cars) haven't survived a track weekend so I'm trying to be very careful. The intercooler setup I've designed should be good for over 2,000hp, it uses a huge water to air intercooler that is cooled by two large radiators that are squeezed into the rear fenders. I still need to fab up some aluminum plates to seal the doors up but its taking shape.

[Stroked & Blown]

Any concern with the rearward swept angle of the rads creating lift as the air goes down through them, or does the wheel well turbulence negate it?

[truegearhead]

Originally Posted by Stroked & Blown

Any concern with the rearward swept angle of the rads creating lift as the air goes down through them, or does the wheel well turbulence negate it?

So I’ll have to admit I really have no idea... look worst case I’ll add some angle of attack to the rear wing. The Front fenders stick out further than rears so it won’t be getting a ton of airflow. Good point though.

[Racer Boy]

Originally Posted by Stroked & Blown

Any concern with the rearward swept angle of the rads creating lift as the air goes down through them, or does the wheel well turbulence negate it?

That isn't an issue. The air exiting at an angle doesn't generate lift or downforce.

[itsnotanova]

Was this car a base or S originally? The S came with bigger coolant tubes from the back to the front.