62-1 or T66?
 

I'm going back and forth between the 62-1 and the T66...

On paper the 60/62-1 is a fit for my bhp goal of 450+bhp. Are there any assumptions baked-into Turbonetics' compressor maps I should be aware of?

For instance, are they assuming sea-level? If so, how should I compensate for that when plotting P.R. v. LB/Min? What about temp, baro pressure, and humidity??? I'm in hot, humid, Southeast US (Georgia), at 1100 ft. elevation, and plan the occasional "mountain cruise" to 3500 ft.

Also, any guesses on how much pressure/volume loss I should allow for between the compressor outlet and the intake (std. bridge)port, assuming a good quality FMIC and associated piping.?

If I'm going to loose 2-3 psi on the trip from the compressor to the port, and some more to warm ambient air temps, and some more to elevation... I'm thinking the T66 is a better fit for my goals.

Thanks for any input.

Steve C.
PS: I was pre-law, not physics.

Remember that the 60-1's effeciency is in the 15-17 psi range. Though its been stated that this turbo can turn 450rwhp, I have yet to see it, in person or on a dyno sheet... I've yet to see more than 424 (BDC's S4 T2).

The T-66, at your elevation will take longer to spool up (since there is less air the higher you go), but I don't think it will be noticeable... but its a simple fact of physics... The T-66 has a higher effecient boost range, which I am uncertain of, but if I remember correctly, is in the 19-22 psi range.

How much boost do you want to run? If you are running a half bridge intake, you may want to go with the 60-1 with a 1.15 or even a 1.32 divided A/R housing... my vote goes to the 60-1 with a 1.15 a/r....

my 2 cents... now, someone come in and tell me how wrong I am :D

Well, this goes to the heart of my question If I'm reading 15psi on my boost gauge (measuring near the lower intake), what is the pressure at the compressor outlet? That is where the compressor's map is applicable, right? Could the compressor be pushing 19-20psi, and loosing 4-5psi in the piping and FMIC? If so, that takes the 60-1 well into the 3rd efficiency island, but leaves the T66 smack in the middle of its' sweet spot. Am I making sense here? Maybe I'm talkin' out my _ss??? I dunno.

Just trying to figure out if what Turbonetics says the turbo is capable of, is what my combustion chamber will actually see.

(My ports, BTW, are a standard RB bridge template on the secondaries only, and RB "race" template on the exhaust. I want to run 15-18psi on pump gas).

Hey, K. I've got a lot of respect for you, your car, and the way its setup. You know plenty I want to learn.

Just one question; what turbo has a compressor a/r of .75 and exhaust a/r of .96

T-60,61,62,66,ect?

yeah ... drop 62-1 idea ... go T60-1 or T66 ... you might want to purchase extra housings if you like to play and dinker.

You're right.
 

Spyfish: Hmm, ok. I looked at the T62-1 plots again, and you're right. The T60-1 and T66 are both better overall performers - just at different PR's. 62-1 is gone.

I'll keep the "extra housings..." advice in mind...

Mostin: visit Turbonetics site, find the catalog, go to Turbochargers and accessories, and look up T3/T4 Series Turbine Housings. All the shapes and sizes are listed there, with measurements and prices.

Still hoping someone can address my concerns with

• pressure (and possibly volume) drop between compressor outlet and intake port, See previous posts.
• what, if any, corrections I should apply for elevation, and
• any other "assumptions" that are baked-into Turbonetics' maps.

Thanks for the replies...

Steve C.