How does this guy do money shift ?

[svandamme]

i'm confused.. short stroking AND turbo'ing an engine? why?
short stroking is good to make it a revvy engine.. But then boosting it?? on such an old design?
with a 915 tranny???

He was going to blow that thing up one way or another..

[beepbeep]

Originally Posted by svandamme

i'm confused.. short stroking AND turbo'ing an engine? why?
short stroking is good to make it a revvy engine.. But then boosting it?? on such an old design?
with a 915 tranny???

He was going to blow that thing up one way or another..

Short-stroking is actually good if you want to make less torque but still have the power. So there is no problem with revvy turbo engine as long as you know what you are doing.

Remember: other than thermal limit (mitigated with oil cooler), gearbox does not really feel power...it is torque limited. You can break it with 100hp turbodiesel or live all day long with highly strung 300hp N/A engine spinning 8000 RPM.

This guy found the limit. And on stock 915, that limit is pretty low.

[javadog]

I don’t think it’s clear whether or not he popped the motor, or the gearbox.

But boosting a high compression, previously normally aspirated engine that doesn’t have any sort of knock control is just a really stupid idea. Looking at his list of modifications, it’s clear that he didn’t do anything to build that thing in a sensible way.

Sounds like a “hold my beer” kind of guy.

[masraum]

Originally Posted by javadog

I don’t think it’s clear whether or not he popped the motor, or the gearbox.

But boosting a high compression, previously normally aspirated engine that doesn’t have any sort of knock control is just a really stupid idea. Looking at his list of modifications, it’s clear that he didn’t do anything to build that thing in a sensible way.

Sounds like a “hold my beer” kind of guy.

Sounded to me like the car was in neutral and coasting, and sounded bad. I'm assuming that points to engine.

[svandamme]

Originally Posted by beepbeep

Short-stroking is actually good if you want to make less torque but still have the power. So there is no problem with revvy turbo engine as long as you know what you are doing.

Remember: other than thermal limit (mitigated with oil cooler), gearbox does not really feel power...it is torque limited. You can break it with 100hp turbodiesel or live all day long with highly strung 300hp N/A engine spinning 8000 RPM.

This guy found the limit. And on stock 915, that limit is pretty low.

Well yeah, but In general, the cost of short stroking outweighs the benefit when turbo'ing non turbo engines. With turbo's making torque much lower.. why would you be short stroking it.. once it spools, more revs will just mean it blows off sooner.

short stroking a 3.2 and then turboing it is not going to get you a modern 3.0Turbo24 valve water cooled block with water cooled charge, designed for power, emissions and revs from the factory.

Old engines, you can do one fancy mod
but when you start combining them you better have a steep R&D budget

[javadog]

This guy looks like he built a short stroke 3.2 first, then decided he didn’t have enough power, and added the turbo.

Bad plan.

[Jeff Higgins]

Originally Posted by javadog

I don’t think it’s clear whether or not he popped the motor, or the gearbox.

But boosting a high compression, previously normally aspirated engine that doesn’t have any sort of knock control is just a really stupid idea. Looking at his list of modifications, it’s clear that he didn’t do anything to build that thing in a sensible way.

Sounds like a “hold my beer” kind of guy.

Originally Posted by javadog

This guy looks like he built a short stroke 3.2 first, then decided he didn’t have enough power, and added the turbo.

Bad plan.

Yeah. He sounds like the urban planners in my city. No real plan going in, and no appreciation of what each subsequent change does to affect the whole, or why none of it works together.

[javadog]

And, if it was really built on a 76 911, that 915 gearbox isn’t as strong as what came later.

Someone should reach out to the guy and see what blew. He has videos posted where he is messing around inside the motor, no idea if that was before or after.

[Jeff Higgins]

Were they still mag cases in '76? My '72 has a mag case, my son's '79 SC aluminum. Did it change with the SC?

[javadog]

1976 was magnesium, 1978 was aluminum, 1977 had both. 915/61.

[spuggy]

Originally Posted by javadog

1976 was magnesium, 1978 was aluminum, 1977 had both. 915/61.

Yeh, build sticker in my '77 says May and original 915 was mag.

[svandamme]

Going by the revs of the engine, and noise after i'de say his engine blew
If it was the tranny, he wouldn't have had his engine noise wind down with the decreasing speed.

Eg his crank still does something, but his valves no longer are there.

had it been the other way around, you'de hear revs up and down, but no accelleration linked to that.
EDIT.. in the end of the video I hear exactly that.. revs a few times but to no result

[Aurel]

This video is 2 years old. From the following videos, you can see that he rebuilt the engine and is back on the road, so it was the motor he blew.

https://youtu.be/6uu5wA4ucHA

https://youtu.be/pO02gT8_nAE

[LEAKYSEALS951]

For some reason, this got in my YT newsfeed- so I watched it fullscreen.

Perhaps mentioned- You can clearly see the owner had installed a digital display in the dash right where the Tach would be located.

This display shows a bunch of data- including the gears selected- and yes- it was a 3-2 shift. Watch the video again if you get bored. Focus on the tach position of the dash when they enter the tunnel. (edit- looks like sugar mentioned it straight up.) Amazing what a quick runthrough it was (I hadn't really watched it till now)

[stevej37]

He prob wishes he would have had a Honda tranny and shifter in his car.

[rusnak]

He didn't "zing" the shift, as in a typical "money shift". It sounded like he was revving it really too high in 3rd, sloppy clutch disengagement made the revs shift higher, and then he short shifted into 4th and then for some idiotic reason, he did it again into 5th. He had too much boost built up and broke a connecting rod or two.