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

[truegearhead]

On Friday I picked up $40 worth of aluminum and started hammering away. Nothing is attached yet so it looks a little wonky, it'll look much better once its been fastened down to the body lines. So far so good though I think its going to work. Once I get it fastened down I'm going to pick up some used e30 oil coolers (which are long and narrow and stuff them into the flare openings. Hopefully the oiling system can handle the additional volume, I still have some research to do on that one.

[Quadcammer]

Hey man i ended up doing a very similar exhaust design, but im finding it very loud and frankly doesnt sound good in my garage.

Do you have a better pic of yours and how does it sound?

[truegearhead]

Originally Posted by Quadcammer

Hey man i ended up doing a very similar exhaust design, but im finding it very loud and frankly doesnt sound good in my garage.

Do you have a better pic of yours and how does it sound?

Here's a close up of how I attached mine. I just the cat delete pipes and slid the 2" exhaust over them. It sounds great but its too loud for the street, I do have headers and no cats which doesn't help. I'm sure with the right mufflers it would be streatable.

[truegearhead]

While I'm waiting for hardware I decided to play around extending the roof line. I'll just move the plexiglass rear window to the aluminum, this will also allow me to ditch the roof cover which is surprisingly heavy

[Starter986]

Originally Posted by truegearhead

On Friday I picked up $40 worth of aluminum and started hammering away. Nothing is attached yet so it looks a little wonky, it'll look much better once its been fastened down to the body lines. So far so good though I think its going to work. Once I get it fastened down I'm going to pick up some used e30 oil coolers (which are long and narrow and stuff them into the flare openings. Hopefully the oiling system can handle the additional volume, I still have some research to do on that one.

On one of the forums yesterday I read a post about someone asking something similar... extra oil coolers. The poster queried why the oil cooler wasn't mounted in the front of the car. A responder replied that the, IIRC, the oil pressure was insufficient to handle all those lines... insificient pressure. If you find a workaround... please share.

[truegearhead]

Originally Posted by Starter986

On one of the forums yesterday I read a post about someone asking something similar... extra oil coolers. The poster queried why the oil cooler wasn't mounted in the front of the car. A responder replied that the, IIRC, the oil pressure was insufficient to handle all those lines... insificient pressure. If you find a workaround... please share.

Well damn thanks for letting me know. I guess my only option is turbo charging it so I can fill the flares with intercoolers. Sigh....

Thanks again for the heads up

[truegearhead]

The roof is done! don't worry about those fender bolts those are being replaced. The car goes into the wrap shop Monday and if everything goes right it'll be back on the track at VIR next week. I have a LONG way to go with the other side of the car.

[itsnotanova]

Looks similar to this top. I think they were made in England. It's the only one I've ever seen in person. Makes you wonder why Porsche didn't design the hardtop with a smoother flow.

[truegearhead]

Originally Posted by itsnotanova

Looks similar to this top. I think they were made in England. It's the only one I've ever seen in person. Makes you wonder why Porsche didn't design the hardtop with a smoother flow.

I think they wanted to follow the soft top lines and maybe distinguish it from the 911. I agree that those lines are much smoother though


In other news I got it back from the wrap shop, I have the narrow front tires on all four corners on these shots (rain setup) so the wheels don't fill out the flares. The slicks are mounted on 4 rear wheels so they fill out the falres

[truegearhead]

I made it back from VIR with good news and bad news. The good news I didn't die... the homemade control arms and various other one off suspension changes didn't break. The bad news is it was slower... by 5 whole seconds. The first heat the car was incredibly loose, its now square (front track is equal to rear track) the front is 7 inches wider than stock and the rear is 4 inchs wider than stock so I expected this to be a big change. I stiffened the front sway bar several times through the day and ended up close to a balanced car. Its still on the narrow 235 series time trial tires so I'm going to wait for wider tires before I make any more adjustments. As it sits its still loose which resulted in a spin at Oak Tree but overall it has far more grip. If I took the widebody off (with its huge fender intakes) I'm sure the car would be faster, I'm loosing a lot of speed down the stretches. I'm now weighing engine swaps, the Audi W12 is an interesting option. Its the same length as the boxster motor and would bolt up to the Boxster S transmission.



Here's a couple shots from the weekend, it was a small social distancing event so the organizer let me and the buddies I run track days with try and recreate the Car and Driver Lightening Lap photo. Super fun weekend, it was great to get out there and bring back a working car.

[paulofto]

Originally Posted by truegearhead

The bad news is it was slower... by 5 whole seconds.]

But it LOOKS faster!

[78F350]

Best looking car in that group shot.
Can you get any sort of analysis of the airflow to see what is helping with grip and what is just creating extra drag? Maybe you could recruit an engineering student to do a CFD model - I'm thinking of the groups that do the $2000 challenge like Georgia Tech or similar.
Engine swaps can be enticing, but most of the cases I've seen, when they are done and all sorted out the cost/benefit is not much different than just going with a higher power Porsche engine. Maybe you should try cutting a deal with some jerk on the forum who keeps pushing his rebuilt engine at a highly inflated price.

I'd love to see your car with the W12 sorted out in it.

[truegearhead]

Originally Posted by 78F350

Best looking car in that group shot.
Can you get any sort of analysis of the airflow to see what is helping with grip and what is just creating extra drag? Maybe you could recruit an engineering student to do a CFD model - I'm thinking of the groups that do the $2000 challenge like Georgia Tech or similar.
Engine swaps can be enticing, but most of the cases I've seen, when they are done and all sorted out the cost/benefit is not much different than just going with a higher power Porsche engine. Maybe you should try cutting a deal with some jerk on the forum who keeps pushing his rebuilt engine at a highly inflated price.

I'd love to see your car with the W12 sorted out in it.

I've done a few engine swaps and ya, they never go well. The 3.4L 911 motors are starting to get cheap but I'm really looking for more power. If there was a cost effective Porsche solution I'd go for it. That being said I also really like the challenge of something odd like a W12, building the car is half the fun for me.

[JayG]

All the new aero could be having a big impact.
Without wind tunnel or CFD modeling, you really don't know if it is good or bad.
Does look really cool however

[Racer Boy]

At the next track day take the splitter and wing off and see the change in lap times. Also note your top speed compared to the later/previous session with the aero stuff back on.

Do you know what the top speed difference is between before and now?

Just looking at the picture, I'd say you have added a lot of surface drag; the flares and possibly the new radiator duct layout, besides the front splitter and the wing may be killing your straightaway speed enough that the increased downforce (hard to say how much increase) doesn't make up the difference.

Another thing to ponder is the air intake for the engine. It's on the back window, correct? That is in a really low-pressure area, so that may be hurting horsepower, which isn't going to help.

[truegearhead]

Originally Posted by Racer Boy

At the next track day take the splitter and wing off and see the change in lap times. Also note your top speed compared to the later/previous session with the aero stuff back on.

Do you know what the top speed difference is between before and now?

Just looking at the picture, I'd say you have added a lot of surface drag; the flares and possibly the new radiator duct layout, besides the front splitter and the wing may be killing your straightaway speed enough that the increased downforce (hard to say how much increase) doesn't make up the difference.

Another thing to ponder is the air intake for the engine. It's on the back window, correct? That is in a really low-pressure area, so that may be hurting horsepower, which isn't going to help.

The flares are the problem, the wing and splitter have been tested on and off, they're worth almost 3 seconds at VIR. I need to have more power, thats the only solution. Especially now that I have these absurd 12" wide rear wheels on the car

[steved0x]

Nice, those are some nice looking wheels, what tires are you going to run on them? What is the widest 17" you can get?

[paulofto]

Are those wheels or beer kegs?

[truegearhead]

Originally Posted by steved0x

Nice, those are some nice looking wheels, what tires are you going to run on them? What is the widest 17" you can get?

Thanks, I’m putting on 315/35/17 Hoosiers today, and 245s in the front. Same setup I have on my 911, I’ll eventually need a wider front tire

[JayG]

Its a very slippery slope