Turboing a big block?

Posted By: polkat

Turboing a big block? - 05/11/09 02:08 AM

Big block Mopars like the 400 are poor candidates for simple build ups due to their poor compression (averaging 7.5 or so to 1). However, this is ideal compression when using a turbo. Has anyone here built a turboed big block, and how did you do it? Thanks!

Posted By: go green

Re: Turboing a big block? - 05/11/09 03:51 AM

Turbocharged and stock .... nope .

Posted By: DARTSPORT340

Re: Turboing a big block? - 05/11/09 03:57 AM

It's probably going to eat the cast pistons before you even get over 8lbs of boost. You could run real cheap head gaskets and use them as a relief point and hope for the best

Posted By: Anonymous

Post deleted by Defbob - 05/11/09 04:25 AM

Posted By: polkat

Re: Turboing a big block? - 05/11/09 06:15 AM

Yea, that's why I'm asking how it's done! Okay, go to forged pistons...what else? What turbo is usually used?

Posted By: topfueldart

Re: Turboing a big block? - 05/11/09 07:06 AM

Turbo choice boils down 1000 percent to your realistic goals.. What kind of power do you REALISTICALLY want to make? How important are the spooling characteristics? At a certain point you have to choose between having low end boost for massive torque, and having a later spool (RPM wise) for higher horsepower combo's...

Posted By: ixelerate

Re: Turboing a big block? - 05/11/09 07:42 AM

theturboforums.com

go to the mopar section and there you will find a great amount of tech and guys there that have done turbos. The torque of a turbo engine is tremendous, meaning that everything in the motor has to be very strong. This also means some serious $. You can go a cheap route of course to save some dough but in the long run you will be paying. Boost tends to break things, and a weakly built motor will not last. On the other hand, a well built turbo big block will create monster power and even get pretty good gas mileage. Turbo 'd cars need lower geared rears which help in mileage and streetability. There are guys running 600 plus turbo motors on the street no problem.

Posted By: Defbob

Re: Turboing a big block? - 05/11/09 11:02 AM

Quote:

It's probably going to eat the cast pistons before you even get over 8lbs of boost. You could run real cheap head gaskets and use them as a relief point and hope for the best

hhmmmmmm................

then I've got problems lol

Attached picture 5221627-007.JPG

Posted By: Defbob

Re: Turboing a big block? - 05/11/09 11:03 AM

I plan on shoving 16lbs atop these

Posted By: blowndart

Re: Turboing a big block? - 05/11/09 01:17 PM

You can do it. You just have a severely reduce margin for error. Run it very rich to begin with, and as mentioned above, very conservative timing.

Posted By: Cab_Burge

Re: Turboing a big block? - 05/11/09 03:18 PM

Quote:

I plan on shoving 16lbs atop these

Not for long

Posted By: turbobitt

Re: Turboing a big block? - 05/11/09 04:29 PM

Quote:

Big block Mopars like the 400 are poor candidates for simple build ups due to their poor compression (averaging 7.5 or so to 1). However, this is ideal compression when using a turbo. Has anyone here built a turboed big block, and how did you do it? Thanks!

I wouldn't say 7.5:1 or even 8.0:1 are "ideal" for turbocharging. For all out performance, I would run 9-10 to 1 compression to keep the spool rate up with bigger turbo's. Fuel managment will be key for any kind of reliability and power.
Allan G.

Posted By: tilt

Re: Turboing a big block? - 05/11/09 04:42 PM

Quote:

Quote:

Big block Mopars like the 400 are poor candidates for simple build ups due to their poor compression (averaging 7.5 or so to 1). However, this is ideal compression when using a turbo. Has anyone here built a turboed big block, and how did you do it? Thanks!

I wouldn't say 7.5:1 or even 8.0:1 are "ideal" for turbocharging. For all out performance, I would run 9-10 to 1 compression to keep the spool rate up with bigger turbo's. Fuel managment will
be key for any kind of reliability and power. Allan G.

This is a statement i've herd a few times recently.Don Bailey was the last person i heard state this (very respected)

Posted By: Cab_Burge

Re: Turboing a big block? - 05/11/09 08:06 PM

Quote:

Big block Mopars like the 400 are poor candidates for simple build ups due to their poor compression (averaging 7.5 or so to 1). However, this is ideal compression when using a turbo. Has anyone here built a turboed big block, and how did you do it? Thanks!

If your going to make a bunch of power, above 800hp, I would use a better block than a stock production block

There are some good production blocks out there but most of the stock production blocks have thin cylinder walls and most of the RB block have thin main webs