Hey there.

I need some help choosing the right size turbo for my 428 ci gen III hemi with a 9.5:1 compression.

It has a forged Manley rotating assembly kit with the H-beam rods and forged pistons and all the good stuff. The engine is boost ready with the complete fuel system and all.

I need to stay in the range of 15-21 psi max as it is kinda of a daily driven car.

currently it has an 88mm/124 compressor with a 102/x92 turbine and 1.32 AR, the turbo is too big and takes long to spool.

Please Take into consideration that the turbo kit is 3" pipes and the exhaust pipe is a 5" that is very short as it is coming out of the driver side fender.

what am looking for is a smaller turbo with a smaller exhaust pipe size that i can manage to custom build an exhaust to take back to the factory style exhaust location ( back side), with the ability to make the targeted boost levels, taking into consideration the turbo kit 3" sized pipes as i dont have much space to make a bigger sized pipes from exhaust to turbo.

any suggestions ?





i attached a pic of the car to enjoy guys XD #ad

 

HP goal ?

 

When is it spooling, when are you shifting, what transmission?

 

It is spooling quiet late, around 5200 rpm. Shifting around 6800 rpm and transmission is a teramec tr6060 that comes from the factory

 

I would expect it to spool sooner, that seems like the right turbo for the HP goal. Any exhaust or intake side leaks?

Did you check that the fire rings are installed in the wastegates?

 

Any pics on the boiler room ?
Would help suggestions!

 

This is probably not helpful: it's a manual. Keep it it over 5200 RPMS when you want the power.

What are you doing for ECM? Do you have a two step?

 

Only 5 ° total on that low boost level is probably slowing down power .
Doesn't sound right, should be more like 20-30 degrees .
Try to add a little at the time and see if the turbo gets happier on lower rpm.

 

definetly way low on timing with 5 psi.

Buddy with a 392 stick combo, s480 x 96 1.32 ar turbine will start making boost at 2000 rpm.

 

Sorry for the late replies boys i just been traveling for work for like two weeks straight. I will get back to each reply separately and i will add more pics

 

nope no leaks of any sort on both side and indouble checked wastegates they are perfect.

to be honest i think the turbo could do that hp target easily but am still thinking of either getting a 79/78 turbo as it is smaller in size and could potentially get to the targeted hp

 

I will get more pics in the next couple of days. Last time i drove it it had a fuel leak so i ordered some parts for it and i will have to take it out for a test drive!

 

Am definitely getting the holley efi for it as i really dont wanna risk it anymore

i already lost 2 engines with this car. One of them was on the dyno with less than 1200 miles on it !

 

i went for 7 degrees and it improved a bit, i will eventually go for that much, but i want to install the holley efi first + its super hot in here man i got to keep it happy until the hot months are over

 

yeah we tried the 392 combo on my buddy's car. We went for a drop in pistons and rods and an 86 sized turbo. That bad boy spools at around 2500 rpm. We faced alot of issues with the 428 though. A bit of back pressure and we had to re do the hot side like 3 times already just to try to manage the back pressure, still might do one more adjustment to the hot side i think

 

Yeah, thats WILDLY low. Take your out of boost timing and pull 1 degree per psi and you'll be on the safe side...

I know the Gen 3 Hemis and the old school engines aren't the same, but I'm running a 426 wedge and at 5PSI I'm still at 36 degrees.

 

Ok, if you have heat issues and want to keep it cooler you should definitely get some timing on it.
Get at least 25°at boost and you will see less heat problems and a lot more respons .
Thinking of down sizeing that turbo, I would not.

 

Good point. Low timing will cause heat issues and compound backup pressure issues on some combos.
Some peeps ive seen struggle with boost control thinking their wastegates where too small.It all had to do with timing just running the turbine volume away from where it should be.

 

36 degrees ! Sheesh i would have a heart attack brother

ill definitely go higher but i dont think i would go over the 20s