thunder550

iTrader: (70)

Looking for some opinions on turbo selection for my 408, mainly compressor size and a/r housing. I doubt I'll spin the motor up any higher than 6300 RPM. I think my cam runs out of steam right around there.

If I go with a turbonetics unit, I'm thinking the Super-T T76. Their matrix recommends the q-trim .96 a/r housing. About what RPM will this spool at?

I called a distributor for Garrett and asked his recommendation, and he told some that a GT42 would probably be about right. He said that a 1.15 a/r might be ok, but that it might generate a lot of heat if I'm hard on the gas towing up a long hill or something (which I will do). He recommended a 1.28 a/r housing, but said that it would probably spool around the 2500-2800 RPM range.

I'm confused as to why the turbonetics unit has so much smaller a/r housing. I'd like to see a little bit lower spool RPM than the 2500-2800 that the 1.28 Garrett a/r offers (especially since I am severely lacking in the low-end torque department due to my 7.0:1 DCR), but I'm concerned about heat and exhaust pressure like the guy said with the 1.15.

What do you guys recommend? Am I on the right track?

NA$TY-TA

iTrader: (21)

FYI the GT42-76 was to small for my 370...... mine was out of steam by 14psi....

Are the main goals for the truck towing???

thunder550

iTrader: (70)

Towing is not the main goal. I want to put the truck in the 10's, but it's still going to be my daily driver. Mostly I want it to be fast and fun to drive, but it will see towing duty as a rig for a 6000 lb boat.

DanaliHD

iTrader: (5)

mine has a ITS 80mm turbo on it right now and today made 615/615 but the tuning isn't done yet. should be upwards of 650-700rwhp when done. that too is on a 408.

have you contacted Jose at forcedinductions? That's who I'd call if I were doing it again. Also, I missed it, are you going T4 or T6?

thunder550

iTrader: (70)

I've been reading your nightmare threads about your truck - congrats on it finally running!

I'll call Jose tomorrow...I've had quite a few people recommend talking to him.

T4 or T6 - I know those are flange sizes, but that's about it Most of what I have seen is based on the T4 flange, but I haven't learned enough yet to know what difference it makes. Maybe that will be tomorrow's goal

bad95killer

Parish8 was running low 10's with his PT88 @ 16psi 'n 100shot assistance

http://www.precisionturbo.net

Give him a call buddy

peace

1slow01Z71

iTrader: (36)

The t-6 flange is commonly known as the "thumper" flange, it is usually for all-out apps, the opening is much larger, you can get a blanket for t-6 flange turbos either. A t-4 flanged turbo will be easier to package and many more options.

thunder550

iTrader: (70)

Ok then, T4 it is

1slow01Z71

iTrader: (36)

meant to say you CANT get a turbo blanket for the t-6 flange turbos

thunder550

iTrader: (70)

Yeah I figured that's what you meant. I'm pickin up what you're puttin down.

Stupid Boost

iTrader: (1)

Yeah call forcedinductions . When I was doing my turbo research, everyone else I spoke to were damn idiots . No one could tell me what my back pressure and intake temps were going to be like and couldn't give me at least where on the compressor map I would fall. All they could quote me is catalog peformance . Jose and Jason answered everything.....by far the most knowledgeble. Also they sell turbos from EVERY manufacture, so their opinion is NOT biased on what they can only sell. Alot of people still don't get that on these message boards. If a dealer sells only Garrett, well he isn't going to tell you if the turbonetics is better.....lol, or if a borg warner is better . .

NA$TY-TA

iTrader: (21)

That may be true but a T4 flanged unit on a 408ci motor is going to have alot of back pressure with that flange........
I have the S88 wich is a T6 flanged 88mm turbo with a 1.26 ar
sppols just fine with my 370..... i would imagine ven better with 38ci more...
Remember.. there a reason Parish went bigger..... she was just about out of steam..............
Kyle

1slow01Z71

iTrader: (36)

Look at how much HP Parish was making though, and he only ran it at like 18psi at the track for his 10.08 pass, thunder is just wanting to get into the 10s and Parish's truck did well towing a heavy trailer for drag week. Just going off what has worked well and what forcedinductions told me would work well for my setup. Thunder and myself have the same setups pretty much, 4XXci motor, 80e, ecsb, 4wd and are both looking to get about hte same thing with me wanting a bit mroe performance thus Im going pt-88 for a bit mroe hp and Im willing to deal with some more lag, he on the other hand is fine with a little less hp and less lag thus IMO the pt-76gts is a better fit for him.