4 cylinder drag racing project car

[Tahnval]

I'm fiddling with this at the moment. The self-imposed rules are:

1) The car must be complete. Lights, populated dashboard, horn, radiator, etc. Sort of like it was road legal.
2) The engine must be 4 cylinder.

Anything else goes.

I've got it down to 8.02s with a full tank.

Current setup:

Kanji
Euroa SLE4 engine
Euroa 2 Turbo L4 manifold with a Euroa 1 turbo in it. I tried sequential twin turbo and it produced less power (797 regardless of which 2 turbos vs 833) and was slower.
Euroa D3R gearbox.
Euroa 4WD diff with 3.00 final gear.
Euroa 1 suspension all round.
255x15 KS wheels with drag tires, all round. Lightest setup I found with enough grip.
Kanji rear exhaust with Walea sports muffler.

Everything else is about weight. So Magura half shafts, Panania control arms, Panania brakes, etc. Comes in at 996Kg with a full tank, but I think I can shave off maybe 10Kg from that. Wanja steering would save 7.5Kg, for example, and it would be fine for drag racing. Panania racing brakes would save maybe a kilo.

Anyone got any ideas for anything else I could do for a faster time? Maybe a suspension change? The Euroa 1 is there because it was originally a circuit racing build but I changed my mind partway through.

Anyone got a faster 4 cylinder "road legal" drag car?

[Craz33Ivan]

https://steamuserimages-a.akamaihd.net/ugc/2062141469333018752/7166DD442F4E4F242324B780EB10F37B528155F8/?imw=5000&imh=5000&ima=fit&impolicy=Letterbox&imcolor=%23000000&letterbox=false
Had a 7.54 with 3/4 tank

[Tahnval]

Would you give me more details about your car and setup? Maybe I could use that to shave a tenth or two off my time.

EDIT: I notice it has a Walea dash. My quickest drag racing car is a Walea UTE I got down to 5.86s. Maybe if I move the parts into a Walea UTE that would be faster. Maybe my drag racing Walea UTE, keeping the same suspension. Something to try. But I'd appreciate any advice, especially since you have a quicker 4 cylinder car already.

[Doc]

https://steamuserimages-a.akamaihd.net/ugc/2089163067666974034/5D4857A1CF7CB441F97C17D41E118E12C02DFF24/?imw=5000&imh=5000&ima=fit&impolicy=Letterbox&imcolor=%23000000&letterbox=false

I got it down to 960.1 kg with a full tank of gas by running the wanja 3.73 rwd diff with tiny front tires and side exhaust with pana muffler. The SLE torque is really weak, so I let the tires spin a little at the line to get rpms up into the power band.

[Tahnval]

I was going with 4WD. Maybe I should revisit RWD for drag racing. I was using the 3.50 Euro 4WD diff. I found the same with the SLE4 powerband. It's completely gutless at lower revs, so keeping the revs high from the start is crucial.

Thanks for the details. They give me some things to try out.

What suspension setup where you using?

[Doc]

Im using walea long front and walea short rear. This was just my baseline though, I never tested anything else since it worked out of the box. I think with less fuel, the suspension dialed in, and possibly a bigger rear tire it could flirt with 6s

[Tahnval]

I've whittled it down to a 7.90, still with 4WD. It's running out of steam towards the end of the pass with a 3.50 diff and a D3R gearbox. Not redlining, but not in the peak power range either. Maybe I'll try a D30 gearbox, which has a lower ratio 3rd gear but takes 0.1s longer to change gears. Then maybe I'll rebuild for RWD with tiny front wheels.

700+ hours in and I'm still finding fun stuff to do.

[Tahnval]

Got it down to 7.60 (still with 4WD) with some suspension changes, exhaust changes (I was using rear Kanji midpipe and a Walea sports muffler, switched to side and Panania as Doc suggested), changes to tyre pressure and a different diff. I could get it quicker but the final gear ratio isn't quite right.

Am I missing something or is there no 4WD diff between 3.50 (Euroa) and 4.12 (Camira)? It's redlining before the end of the pass with a 4.12 and slower with a 3.50. I think ~3.90 would be optimal. Gearbox has to be a Euroa D3R because the shifting is faster than with any other gearbox, so the variation has to come from the the diff.