Inliners International Forums General Discussion Blown and Injected Building a 250 turbo for Bonneville

Hey guys, new here, thought I could use some of your expertise.

We are about to start building our first bonneville car. The engine will be a 250 with a single turbo.

Very little details have been set, as one can affect the other, still trying to figure out what we need.

The block will be a 250 with a max overbore of .030"
Plan on using 6.00" small block small journal rods with cap screws to help with clearance.

Pistons will have to be custom made, most likely JE or Aries.
Looking for 9:1 compression

O ringed block

Head will be a lump port, plan to use beehive springs, and Comp Pro magnum bbc rockers.

Cam will be flat tappet solid most likely from Comp Specs unknown at this time

Intake will be a clifford single four
Barry Grant demon blow through carb

Turbo size is unkown at this time Looking for 10-15 lbs boost

The goal is a power peak around 5500 to 6000 rpm

Car will run on 110 race gas.

Any tips would be greatly appreciated. I have Leo Santucci's book, and have read it several times.

Have Corky Bells Maximum Boost on the way.

We are used to building 1/8th mile big block drag cars, so this is quite a change for us.

turbonetics 62-1 turbo would be a good size. use a P trim exh wheel and a .68 housing. it will spool real good around 3k rpm and not choke the motor in the higher rpms.
use a cam with 112-114 lsa.

What are your power goals? What class or speed do you intend to run in? You need to find your power goals before you build a combo that will or won't fit your needs.

No matter what the answer- I would reccomend that you invest in a ball bearing turbo like a GT series. In your case, a GT67 would deliver lots of air right in the peak efficiency zone... which will produce minimal heating of the air. Unless you are bound and determined to avoid the use of an intercooler- I'd suggest you consider it.

Thanks so far.

Power goals, I would love to see 500hp at the flywheel.
Class is E/CBGC. Current record is 152 and change. I would like to get close to 175 but just setting a new record is the goal for now.

Car is a 1981 camaro, so it is somewhat areo. Gutted full race car, pretty lightweight. I have no problem running an intercooler.

from some quick calculations, you are going to need around 20 psi of boost. maybe even more. that is to achieve the 500hp mark. this engine will need to be intercooled also.
the turbo needs to have a high efficentcy, like 75% and so does the intercooler.
also V8 rods are too narrow on the crank end to use.

Thanks for the help.

Can you give me a ball park figure on what a good set of rods, pistons, and a lump port head cost?

Alos, if you could point me in the direction of suppliers, I have been haveing a hard time finding any.

Just trying to get a cost idea, so I can weigh my options.