Wreck to Race.

[Peter Jones]

Talked to the dyno shop today, the car's had it's first run up on the dyno and now they're figuring out how to best address the issues.

This is what they observed-

Running rich accross the board 10% CO

Power drops off dramatically at 5000 rpm (That's why I took it there)
60kw (80hp) at the tyres
He didn't mention torque figures.


So roughly 110hp (82kw) at the motor which is about stock power levels.

(Stock quoted performance for a MK3 2.0L is 85kw@5200RPM, 170NM@2400RPM )

The CO figure doesn't surprise me, I did hack at the main jets with a Bunnings drill bit on the side of the track to stop it burning plugs remember!

The power drop off is very sharp which is what I observed on the track and the main problem I'm trying to solve.

The power level doesn't surprise me based on long long time it was taking to reach top speed on the straights.

I'm going to need a lot more horsepower in the track car, so I'll probably have to spend a little more than the $50 (apart from the carbs and cam.)
that this motor cost me.

Pete

[Preen59]

All very interesting, Pete! Thanks for the write up!

[Oneofthegreats]

Good new's they've started to sort it out for you Pete.

Just for interest sake & a basic measurement.

My GX with 9.5:1 CR, matched ported cyl. head made 66fwkw's or 117engine hp 10 year's ago.

That's without the volvo k-jet gear, audi throttle body etc. It did have extractor's & 2" exhaust.

Your engine should make inexcess of 80fwkw's or 135+hp! easily if tuned right.

My GX at the end of it's life was making approx 135+hp. The 2L should rape this

[Peter Jones]

Who would have thought I could make a stock motor with twin Dells and a TT cam!

Does kind of explain those lap times .........

The power drop off is very sudden, almost like an igntion breakdown, I'm hoping there's a simple answer in there somewhere.

There's crazy torque available it's just too low in the rpm range to be used on a track. Awesome fun to tramp mid corner though!


Pete

[GoLfMan]

i recon its your ram tube's i experienced the same problem before i changed to a ramflo... then it revved like a demon

[Preen59]

i recon its your ram tube's i experienced the same problem before i changed to a ramflo... then it revved like a demon

Can you back that up with some technical input, other than the fact that you changed the same thing and found an improvement? That doesn't make much sense to me...

[Jarred]

Preeny, he says this because, his car didn't run great at high rpm [5k] with the ram tubes, but did once he had a ram flo filter.

basing this on the ram tubes bein so close to the firewall that it's restricting air flow into the engine at 5k rpm and above. but the ramflo filter isn't as close to the firewall, hence breathes easier...

coincidental that josh car and Petes car ran outta puff at 5K rpm.

[Preen59]

Preeny, he says this because, his car didn't run great at high rpm [5k] with the ram tubes, but did once he had a ram flo filter.

basing this on the ram tubes bein so close to the firewall that it's restricting air flow into the engine at 5k rpm and above. but the ramflo filter isn't as close to the firewall, hence breathes easier...

coincidental that josh car and Petes car ran outta puff at 5K rpm.

Well thats a decent theory, however i doubt it, considering the number of MK1 golfs that run fine with large ram tubes and sock filters. I'd say it was moreso that the new filter was a bit more restrictive and therefore effectively made the mixture richer.

Generally webers won't perform well without good ram tubes as they need a good atomised mist above the throat to ensure a consistant well atomised charge enters the cylinder.

Your filters have the springs in them, right Pete?? I know it sounds silly and i don't think you would have forgotten them but i figured its worth putting the point forward.. Because if they don't it could be sucking your filters in at high RPM and choking the engine...

[Peter Jones]

Yes my filters have springs in them.

My carbs are also a lot further away from the firewall than Josh's.

Being duals my manifold is very short, Josh's single carb manifold has a lot of bends in the manifold and puts the single carb very close to the firewall.

I have 50mm tubes and there's still at least 100mm to the firewall from the top of the tubes.

Bit hard to see in any photos I have to hand but there's plenty of room between the top of the ram tube and the firewall.



I wish it were that simple.

Pete

[Peter Jones]