gt37vgt

bit of contradiction there wormhole ... I agree boost turbo maps go bad above 22psi so i there for feel anyone running more then 22 psi has too low compression .. from asking every one on here with the same combustion chamber it seems 9.5:1 i will be able to run some where between 15 to 19psi on 98 octane and more than 22 on e 85 ..
keeping it together is all about being patient when winding the boost up have plenty of instrumentation.

Wormhole

I guess it depends on what your intention is. If you are running high compression to get you through the city where you see low rpm, I can understand. If your talking about a track car the approach doesn't make any sence to me. I've been assuming track but maybe I'm wrong. Your killing the efficiency of a turbo for a power band you will never be in.

Duke

To me it's the other way around. 99% of the CR people run in these engines doesn't make sense to me. 8.x:1 and <18 psi. Safe yes, efficient no.
Higher CR has many pros. As long as you're not knock limited you can reach a given power goal with less boost, meaning lower intake temps.

With 9.5:1 and a 16v head I expect to be able to tune it up to 20 psi safely on pump gas, would I want it. But that is not my intention. Besides, this engine will be run (after break in and base tune) on E85. On E85 I could run 30 psi, but then I have to start worrying about other stuff!

I don't intend to run more than 18 psi on E85, which should easily surpass my modest goal of 500 bhp.
But then again those are strong swedish horses

Duke

Regarding variocam it should be easy to find the sweetspot. One dyno run with it activiated, one dyno run with it deactivated. Overlay dyno runs and pick the best of the 2 worlds

333pg333

Possibly a stupid question, but since we measure EGTs at some point on the headers is this only because we can't easily measure the temps inside the piston on the exhaust stroke, or is it because this is just where you want to measure it? So if it's the latter, then does the length, diameter, or design of the header pipes have an effect on the EGTs?

Seems to be a balancing act at times. Or sort of like that sideshow game where you have to hit those critters on the head when they pop up through a hole, only for them to appear out of another. So we juggle with C/R, boost, timing, EGTs, mix, etc....Guess that's why the good builder-tuners keep getting repeat business.

gt37vgt

I asked about the long manifolding to the turbo shedding some heat on here .. and it came back that the temp difference along the manifolding was very little also as there is a Bottleneck (turbo) at the end the pressure would equalize in there very fast i therefor hypothesis that there would need to be a drastic change manifolding to see a significant temp change ..

95ONE

Naw different pistons and rods.. Sleeved block. Pauter Rods and Custom pistons with a longer skirt and a few other designs to help with Strength. I might source Chris white on that one. But I know they can make the same 11:1 piston that's stronger for Turbo duty.

95ONE

Yep... Exactly how we tuned the VTEC changeover when we turbocharged it or change to a more aggressive cam. just 2 dyno runs.. Overlap them, and set it to the point they cross.

Chris White

If I had a good source of E85 and PCA would allow it the track car motor would be over 11:1 ..... Possibly way over 11:1!

There are some very interesting games you can play with Ethenol. For instance you can add lots of water to it and retune the mixture. Adjust the mixture injection to reflect the correct Ethonol to air ratio ( compensating for the added water) and you have built in water injection. In theory you could run diesel like compression ratios!

Chris White

Variocam works on the intake cam only. 15 degree timing change on intake and nothing on the exhaust cam. As I said.... It's a little crude by modern standards.

Chris White

Cam twist on a 16 v? That used go be a problem on the old CanAm V8 way back when....but they were longer cams with much higher spring rates. Even with that the problem that they suffered from was the change in ignition timing because the distributor drive was on the back end of the engine. Not a problem for us!

951_RS

well, newer direct injection motors like my gti have a 10.3:1 (10.5:1 in the earliest examples in Europe) and I spike over 26 psi on 93 octane. Holding about 18 psi to redline. The stage 3 kit sees over 20 psi until redline with stock internals. I do realize though that the 951 engine is much older and obviously not advanced enough to do these things without some major modifications.

I think it has a lot to do with the tuning and the efficiency of all parts working together in the end.

Duke

Alright, it's time for some more green stuff

FueLab Prodigy 41402 fuel pump + fuel filter.
IMHO the best fuel pump on the market. The size about a 044, pretty lightweight, variable speed control, brushless motor, low noise, massive flow (rated at 1300 hp N/A).. High price though.

Olli Snellman

Gustaf,
Those parts look like color coded to Gröna Jägaren

gt37vgt

High price .???? Scoff .... go price up a pair of 044's and the extra fittings ...