Setting Diesel Track Records

I am currently talking to the grad program here http://www.kaist.edu/html/en/index.html.

I think we can crush the diesel track records in east Asia for relatively little money. Please let me know cool ideas you would like to try on a no-holds barred time attack "car."

The only restrictions are:

1. Relatively cheap.

2. Production diesel engine and drive train. I'm probably not going to get above 250/300 hp.

3. No exotic materials.

My ideas so far:

1. Anti-lag run on compressed air. Compressor connected to rear differential and only kicks on under braking. Idea is to get "engine braking" for a diesel while keeping a (big) turbo spooling.

2. Dual chassis. Idea is to avoid all wings, develop a thousand or so pounds of down force with streamliner drag coefficients.

3. Sucker fans mounted on top of the dual chassis. They will be wired to turn off when there is no steering angle and no brake pressure, so the engine doesn't have to work so hard spinning a (probably very large) alternator.

4. Variable camber in the front. When the braking system engages, it hydraulically engages a piston mounted behind the top, inside a-arm mount. There will be a spring loaded sliding bearing the a-arm is mounted to, allowing the camber to "stand up" under braking and return to -4.5 (or whatever) once the brakes are released. Rear will probably be a stick axle.

5. Fully enclosed front and rear wheels. Use the sucker fans to draw large quantities of air over the front and rear disks.

Please, give me crazy ideas.

If you're going to have suction fans, you may need a secondary engine to run them- why not use it to power the antilag or spin a supercharger as well?

¯\_(ツ)_/¯ wrote: If you're going to have suction fans, you may need a secondary engine to run them- why not use it to power the antilag or spin a supercharger as well?

Interesting idea. You could use one of the divided exhaust housing turbos like an S400 and run the supplemental engines exhaust to one side and the drive engines exhaust to the other. Baseline boost with the supplemental engine and flow control with the drive engine.

MrJoshua wrote:

¯\_(ツ)_/¯ wrote: If you're going to have suction fans, you may need a secondary engine to run them- why not use it to power the antilag or spin a supercharger as well?

Interesting idea. You could use one of the divided exhaust housing turbos like an S400 and run the supplemental engines exhaust to one side and the drive engines exhaust to the other. Baseline boost with the supplemental engine and flow control with the drive engine.

jesus so much awesomeness in so few posts! i like where this is going

Can't you just use a 1000 hp 5.9 cummins in a very small car? Seems easier.

MrJoshua wrote:

¯\_(ツ)_/¯ wrote: If you're going to have suction fans, you may need a secondary engine to run them- why not use it to power the antilag or spin a supercharger as well?

Interesting idea. You could use one of the divided exhaust housing turbos like an S400 and run the supplemental engines exhaust to one side and the drive engines exhaust to the other. Baseline boost with the supplemental engine and flow control with the drive engine.

This is a fascinating idea if I end up needing a supplementary engine. My plan was to run about 10 hp worth of electric fans off of a very large alternator(s). Would that be too much draw for an alternator?

If I needed something huge, I was thinking of running it off the drive shaft and having it kick on only under braking.

Actually, with enough alternator/compressor on the rear axle, I might be able to use the rear brakes as backup only ... hmmm.

bearmtnmartin wrote: Can't you just use a 1000 hp 5.9 cummins in a very small car? Seems easier.

Correct me if I'm wrong, but that sounds very expensive, very peaky, very heavy and like it would have a very high center of gravity.

Honestly, conceptually conventional and expensive sounds like the exact opposite of what I want.

Heavy yes, but not peaky for sure, and around here they can be had for $1500 which I thought was pretty cheap. And you can get all the horsepower you need with hand tools.

Really? I thought a 500 hp Cummings was a $10,000 proposal.

If it's really that easy, that would be tempting, though I'd still do the anti lag and dual chassis stuff.

ive seen several 800+ hp 12v 5.9's that are still on stock bottom end and live a long life. just give it fuel and boost and keep the head on and they do alright

It weighs 1100 pounds dry. I don't think that will work.

They have high center of gravities because you usually see them in 4x4 pickups.

1,100 lbs of engine + 1,000lbs of chassis + peripherals = 2,500lb 1,000hp beast.

Are these high speed tracks, or technical?

For anything without crazy high speeds, I'd just build a Miata time attack car and replace the engine with a VW TDI.

ProDarwin wrote: Are these high speed tracks, or technical? For anything without crazy high speeds, I'd just build a Miata time attack car and replace the engine with a VW TDI.

This.

We need to know what sort of engine you're thinking about here- what is available over there? A Cummins is what people in the USA come up with because it's what we have here.

I would plan on having a second engine if you want significant suction from the fans, it takes a lot of power to move that kind of air.
How about thrust vectoring with the fan exhaust for cornering/acceleration?
Active aero elements? Have the thing covered in flaps so it goes nice and teardrop shaped on the straights, then turns into a berkeleying Gundam when you hit a corner/braking zone?

ProDarwin wrote: Are these high speed tracks, or technical? For anything without crazy high speeds, I'd just build a Locost time attack car with a VW TDI.

FTFY

Driven5 wrote:

ProDarwin wrote: Are these high speed tracks, or technical? For anything without crazy high speeds, I'd just build a Locost time attack car with a VW TDI.

FTFY

Depends on the speeds. Miatas have crappy aero, but a Locost has really crappy aero.

Remember, weight of a full-prep Miata without class limits is pretty crazy low.

ProDarwin wrote: Depends on the speeds. Miatas have crappy aero, but a Locost has really crappy aero. Remember, weight of a full-prep Miata without class limits is pretty crazy low.

Much like weight on the Miata, aero on the Locost can be readily improved.

True... but it depends on what "relatively cheap" means.

Yep...Just like with building a full-prep time attack Miata.

It's probably going to be based on the front and rear subframes off of a rwd van called a Starex.

Everything in between will most likely be tube chassis.

The suckers become more efficient the wider and longer they are. Thus I need a very slim "inner chassis" and a relatively long wheelbase for the outer chassis.

Seems better to avoid a production unibody.

Driven5 wrote:

ProDarwin wrote: Are these high speed tracks, or technical? For anything without crazy high speeds, I'd just build a Locost time attack car with a VW TDI.

FTFY

The idea is to be good at both.

I should emphasize labor is essentially free.

Specialized engines, carbon fibre and pimped big brake kits are the sorts of things I can't afford.

¯\_(ツ)_/¯ wrote: We need to know what sort of engine you're thinking about here- what is available over there? A Cummins is what people in the USA come up with because it's what we have here. I would plan on having a second engine if you want significant suction from the fans, it takes a lot of power to move that kind of air. How about thrust vectoring with the fan exhaust for cornering/acceleration? Active aero elements? Have the thing covered in flaps so it goes nice and teardrop shaped on the straights, then turns into a berkeleying Gundam when you hit a corner/braking zone?

I can get a Cummins, it would just come out of a city bus or in town semi truck.

I was thinking of using either a 2.9l Mitsu based 4 banger (Hyundai J series) or a Benz based 2.7l 5 cylinder.

I base this on the fact they are both easy to source and tune in Korea. 250 to 300 hp without smoke or reliability problems is doable without anything nutty.

I really like the active aero idea. Maybe a teardrop tale that turns into a giant airbrake?

Would 10 hp worth of thrust be significant?

I'm basing that 10 hp estimate on the Cheapparral Vette, btw.

The Cheapparral Corvette used a 40hp engine to drive the fan- I would expect you'd want even more. The thrust from the fan exhaust can become more useful with clever ducting.