My 67 CJ5A

2psi will bring my effective compression to 10.06:1, and will add very little power. 7psi will bring my effective compression to 13.13:1, rather high, but workable with the correct ignition retard and proper fuel mixture. Below are a few maps at different boost levels, I know these are exact, but they give a general idea:

0 psi (simulating stock):



2 psi (notice I'm out of the sweet spot for this particular turbo):



7 psi (looks very torquey and right where it needs to be in the turbo map):

 

Looks like you have it all worked out. Good luck with your project.

 

Thanks for your input, I'm open to suggestions. I may look in to an MLS style headgasket to lower the compression a bit. will 231 gaskets work? How about 300 v8 gaskets cut down? That turbo looks like it would be happier around 15psi, but that won't happen without forged components. not to mention I don't want to replace my entire drivetrain.

 

Found a source for MLS headgaskets in varying thicknesses. I should be able to get away with a decent amount of boost going this route:

 

If I were building a turbo motor, I would try and get close to the ratio in the turbocharged buick grand national which was 8:1.

 

That was 8:1 static, add in the stock 10psi of boost and effective is about 13.5:1. Granted the GN engine had forged internals and piston squiters.

 

I got my ECU (megasquirt 2), coil pack & driver (Audi v6), trigger wheel and pickup (ford edis 36-1 wheel), GM 4.3 TBI, GM 2 bar MAP sensor, and my K04 mazdaspeed turbo. I still need a 3.8 drivers side exhaust manifold to mount on the passenger side so I can start plumbing the turbo in. I'm going to try using one of those cold air intake systems for a TBI truck as my charge pipe (hopefully it can handle 7-8psi).

 

Interesting.... I'm just starting a 67 CJ5 turbo project. Its an 84 Grand National motor.

 

You'll be miles ahead of me using a gn motor as a starting point, but I can't see starting all over when my engine has less than 1000 miles. I should be able to sell off my HEI distributor and edelbrock 1403 carb pretty easy too. I've seen GN engines pushing over 30psi with no issues, will need to beef up your drivetrain for sure though.

 

Well I don't plan on changing the performance to much. I'm gonna leave it alone for now.