C-4 Now

Street turbo motors what gives least long term problems?? Advantage/disadvantage of each?? Looks like limited choices in 4.125 bore sizes w/o going custom?? Thanks in advance and hoping some of you have put some mileage on your combo!!

mn_vette

Ike,

Your profile says that you have an '89 callaway. Did something happen to your engine? Give us some details on what is going on and we can help you better. The 4.125" bore is for a 400ci block, Unless you've upgraded you are with a 350ci block and need something in the range of 4.00+0.060" bore.

Baldturbofreak

The 2xxx series alloys are stronger but have a larger coefficient of thermal expansion. They will deform and go "plastic" in their failure mode.
4xxx series alloys have more silica. They expand less and are therefore more quiet in operation. However the silica makes them a bit more brittle. Their failure mode is more of a fracture.

C-4 Now

I have a Bowtie sportsman block and some other pieces that I was collecting for NA 400+sbc before I bought Callaway. No problem with 11,000 mile motor just want motor to rip on a bit without worrying about breaking it Besides the fact that turbo technology has come a long way since Callaway was designed! I have read most everything I can find on pistons. Was just wondering about personal opinions of some of guys here that have built some pretty serious turbo/blower power!

mn_vette

You'll want to make sure that you don't get an engine that sucks up more air than the turbos can provide. Alot of thought went into matching those turbos to the 350ci engine. If you build a killer engine, you'll definately need to upgrade the turbos to take advantage of the new engine airflow.

C-4 Now

Ya I had already figured that out and have several of the good Turbo books. Only problem with this process is it will lead to next weak link in drivetrain! Only rule for buildup is it has to look Callaway original when open hood! That was original draw for these cars. Sleepers w/o Areobody! Who's afraid of the L-98

Baldturbofreak

Turbo technology has come along way as well. Are the turbines t-28(t-25) or t-3 based? Garrett makes t-28 flanged internally gated turbos that provide 475+ fwhp worth of flow. In fact they make no less than 5 turbos that fit the smaller flange.
T-3 starts to get bigger. I dont think any except the journal bearing turbos are internally gated. Im betting it's not due to the space constraints.
One way to get around the driveline breakage is turn the motor higher.
Same torque @ higher RPM = big hp
Nuthin' beats the sound of ol red (see pic left) screamin' "whaddaya doin to me??!!"@7400.
My next build has some new manley Ti valves (old nascar stock for cheap $200) much bigger turbo and more headwork that says Im gonna bend over 8k on the tach.

mn_vette

Does anybody know what kind of turbos are on the callaway? Is there a special flange, downpipe hookup, or other crazy thing like that?

If it was as simple as bolting on a new turbo then you're good to go, however, I'm guessing someone like callaway would have done something weird to prevent that.

heimo huima

They are rotomaster to4b. I`m in a middle of changing them for
bb garrets. I would like to get gt3076. Has anybody any idea would
these fit in there?