TheSamba.com :: View topic

Mon Sep 15, 2025 5:52 pm

yeh the whole not running a waste gate might work for low boost but not anything else. id definitely overboost my rail. one time I was in a Honda that had an Acura engine swap and boosted too, to my surprise that thing went from 3k rpm to like 7k in a split second , there's no way in hell you could shift fast enough to control boost in that thing, you could barely shift fast enough, period.

in theory I guess you could pick a turbo that'd not flow enough at high rpms but in doing so your running that turbo outside of its efficiency range , and for how long before it "stalls" ( for lack of a better term).
not saying you didn't do it Oprn, or that it wouldn't work, these are just the problems with doing it. thinking more about it, if anything I'd bet your turbo was too big and wasn't spooling up which is why you could do this.... still running outside of its efficiency range either way you go though

Tue Sep 16, 2025 3:25 am

It was a Rayjay sized for a 1584 but on a 1737. Reached crossover at 2300 RPM. If I did a flat out run through the gears this is about how it went if my memory serves.

1st 6 psi 5000 RPM, Wheel spin hard to control
2nd 12 psi 5000 RPM
3rd 15 psi 4800 RPM
4th 15 psi 4200 RPM

Stock Rabbit gearing. So if anything it was sized a bit small by most fellow's standards.

That would be pretty poor at the strip I am sure but I don't normally drive that way, it's a street car. To put it in better perspective if driving 60 mph/3500 RPM at no boost and pull out to pass, by the time I am beside the car I'm at 80ish, 4800 RPM, 15 psi and the front tires are starting to drift with the road crown. Time to back off the loud peddle pressure.

As for high RPMs... don't do that, no need to. I have all the power I need at moderate RPMs. That is the beauty of turbo boost! Before the turbo I used to flog that engine up to the 6250 factory red line on a regular basis. No need to now.

Afterthought here, I don't believe the turbo Corvair had a wastegate. Correct me if I am wrong...

Tue Sep 16, 2025 5:57 pm

well that's pretty interesting, can't say ive ever seen it work but that doesn't mean it can't! I would've liked to have rode in it.
I do have some corvair engines and stuff but not any of the factory turbo stuff so in all honesty I can't say that they did or didn't but so far I haven't seen a set up without, again that doesn't mean anything though.
I'll have to do some research on that

Tue Sep 16, 2025 8:30 pm

Ok, so according to the page ( link below ) the corvair did not use a wastegate.
Supposedly boost was limited by design , restriction of exhaust and flow of carburetor. Carb i guess i could see as its been said that carb will limit boost of a supercharger when cruising at part throttle.
https://macsmotorcitygarage.com/turbos-for-the-people-1962-corvair-monza-spyder/

Tue Sep 16, 2025 8:44 pm

There you go! You learned something, now you can have the rest of the day off!

:D

Wed Sep 17, 2025 6:30 am

Thanks to tech support at Turbosmart and Chip, I discovered, once again, that my exhaust leak at the waste gate was "self inflicted" :oops: :oops: :oops:

I saw the shiny ring in the waste gate box, but the instructions made no mention of it :roll: :roll: :roll:

So the "flame ring", otherwise known as the valve seat has been installed :idea:

And the afr sensor has been relocated to the turbo outlet.

Once the rest of the neighborhood wakes up, it'll be testing time again!

Stay tuned

Wed Sep 17, 2025 8:06 am

That would do it!