Help choosing a turbo

[BuiltMK3]

I'm having some trouble deciding which turbo i should be running on my car. I have an 88 targa with a fully built 7m-gte. My goal is 700whp. The car will be driven both on the street and on the track. There just seems to be so many choices i can't decide which to buy. It seems like the more i read about this the more confused i get. I am leaning toward the gt35 or 40 but i don't know what trim or a/r would be best. Any advice would be greatly appeciated.

Thanks
Geoff

 

[Slow66]

I have a turbonetics super t-76 dbb for sale with the q-trim, .81a/r turbine if interested....will easily support your goal. PM if interested.

 

[Supra5MGTE]

i'm looking at what size/brand turbo I should go with... Turbonetics or garret.. not sure what the pros/cons are of each turbo. i'm looking to make big power too.

 

[socc924]

But how bad is the lag with a T-76. It just seems that if a T-76 is good for 1000hp and his goal is only 700, he could go for a smaller turbo that will spool quicker. Or could he just change one of the wheels to make it spool quicker. What would be best for drag racing if he wanted to do that?

 

[empera]

sp67GT mofo!

"The 67GT turbo can flow upwards of 700+ RWHP while the HO version can see 750RWHP without much sacrifice in spool at all. "

 

[dbsupra90]

the problem isnt the turbo, but the rev limit. a turbo big enough to make that kind of numbers isnt going to flow enough to make it using the stock rev limit. of course you could use spray. you will be hard pressed to make much more than 650rw range on a stock rev limit car.

 

[IJ.]

A 3540R won't have the overhead for 700 rwhp.

I agree with Dave you're going to be looking at more rpm just to get enough flow to turn a big enough turbine/compressor to reach your goals.

There are no "Magic Turbos" they all obey the laws of physics

 

[BuiltMK3]

A 3540R won't have the overhead for 700 rwhp.

I agree with Dave you're going to be looking at more rpm just to get enough flow to turn a big enough turbine/compressor to reach your goals.

There are no "Magic Turbos" they all obey the laws of physics

I'm not looking for a "magic turbo", just one that will allow me to accomplish my goal. I would rather ask now and buy the correct one then guess and get something that won't make enough power or spools at 6500 rpm's.

As far as the rev limit i would assume i could go higher then the stock limit since the bottom end and head are built. Not sure how high though. How high do people typically rev with built motors, or how do you determine how high you can rev?

 

[Supra5MGTE]

I'm looking for 480-500 RWHP, is that realistic? I wanna keep the stock rev limit, and am looking at a Tubular SS manifold and the Garrett GT35/40R.

 

[IJ.]

Built: Sorry if I came across as a cockhead I didn't mean to it's just that it takes XX amount of Air and XX amount of fuel to = XX RWHP and this is why I said a 3540 just doesn't have enough overhead to make 700 at the wheels.

You'd need to really wind the boost up even to get 700 out of it which means expensive mangement to keep it under control and no corners cut in the build.

5M: I think a .82 AR 3540R would fit the bill but may take 20+ psi to achieve it.
(see above)

 

[MK3Racer89]

my friend has a fully built mr2 and he revs it about 7500-8000, so i would think maybe around there. i also heard that inline 6s can rev high

 

[shaeff]

i also heard that inline 6s can rev high

ANYTHING can rev high with deep pockets. you cannot take a built 7m with a stock head, and expect more performance out of it at 8k rpm, than at 6500rpm.

the valve springs will NOT support that many rpm, they just cant. by fully built, we hope that he has a fully built head, too, and if he does have AT LEAST upgraded/heavier valve springs, then of course, valve float will not be much of an issue, if any at all.

then, of course, comes into play the "long stroke" of the 7m. personlly, (yes, my opinion) i think the 7m can be wound to 8k rpm safely with a built head, and a balanced bottom end.

stating something such as "i also heard that inline 6's can rev high" is an overstatement, simply due to the fact that ANYTHING can rev high if you have enough money. my '71 chevy c-10 doesnt like going past 4k rpm, for example. it's an inline 6. my buddy's old mustang had an inline 6 and hated the upper rpm.

-shaeff

 

[BuiltMK3]

the valve springs will NOT support that many rpm, they just cant. by fully built, we hope that he has a fully built head, too, and if he does have AT LEAST upgraded/heavier valve springs, then of course, valve float will not be much of an issue, if any at all.

then, of course, comes into play the "long stroke" of the 7m. personlly, (yes, my opinion) i think the 7m can be wound to 8k rpm safely with a built head, and a balanced bottom end.

-shaeff

My motor does have a fully built head, with 1+mm ferrea valves and springs. The motor i'm using is the one that Dr. Jonez was selling about 4 months back.

 

[shaeff]

snap! you shouldnt have any problems, then.

-shaeff

 

[BuiltMK3]

snap! you shouldnt have any problems, then.

-shaeff

So now that we have determined that the rev limit shouldn't be an issue, do you have any suggestions for a turbo to accomplish my goal. How do you feel about empera's suggestion of the sp67? Looks like a pretty good turbo to me. Horsepower freaks says it's good for 700hp but how do they determine that? I would think performance would be different depending on the type of motor you're running. Seems like a pretty vague statement.

 

[empera]

spell my name right bitch!
listen just buy the turbo, slap it on and if u dun like it...sell it to me

 

[shaeff]

the sp67 is a good turbo. however, i'd fabricat your own turbo oil drain line, as i've heard (i think it was the SP turbos) that they arent really that good. HPF is a good, honest company. you should try to find people's dyno graphs here or on SF, from people with the SP67. put it this way, dr. jonez made 430ish rwhp on a SP57 turbo. the 67 is quite a bit larger, so i have no doubt in my mind that it could support 700hp.

well, considering that our motors are 3.0 liters, they're relatively large as import car motors go. (save for the real big ones) it might not hurt to call them and ask them specific questions about them, such as the one you asked above. they're pretty knowledgable people, and i'm sure that they could help you with that. hopefully another turbo guru will pop in here, and perhaps answer your question better than i have.

-shaeff

 

[BuiltMK3]

spell my name right bitch!
listen just buy the turbo, slap it on and if u dun like it...sell it to me

LOL, sorry about that man. All fixed now.

well, considering that our motors are 3.0 liters, they're relatively large as import car motors go. (save for the real big ones) it might not hurt to call them and ask them specific questions about them, such as the one you asked above. they're pretty knowledgable people, and i'm sure that they could help you with that. hopefully another turbo guru will pop in here, and perhaps answer your question better than i have.

-shaeff

I have called Ron at HPF (i believe he is the one who replaced, or is taking over for jeff). I left him a voice mail last week but i haven't gotten a call back yet. Maybe i'll try calling again later.

 

[dbsupra90]

the sp67 is a good turbo. however, i'd fabricat your own turbo oil drain line, as i've heard (i think it was the SP turbos) that they arent really that good. HPF is a good, honest company.


-shaeff

sp and hpf turbos come from precision, the same place mine come from. out of all the turbos sold b/w dave and i there have only been 2 returns. hell even the guy that hooked his oil drain line to the oil pan didnt blow it up!

just my thoughts.

edit: re-reading that maybe you are talking about the oil drain itself and not the turbo?

 

[Nick M]

There are no "Magic Turbos" they all obey the laws of physics

Sure there are. They run $69.95 in the back of Turbo magazine and SCC. Havent you seen them?:nono: