Best turbo for max HP on the street (pump gas/no alchy)?

[subsolar0]

I was just wondering which turbo would produce the most HP on pump gas/no alchy. I know a bigger turbo will make more HP at higher boost, but will the biggest one also make the most HP at 15-17 psi? I'm trying to setup a combo for my daily driver 87 GN. Have a 3200-3400 stall 9x11 and will be rebuilding the engine pretty close to stock (maybe a little bigger cam and ported heads). I'm thinking some sort of ball bearing turbo will be the best for the street?

[PhilM]

I would just say the 44 would do just fine...

Phil

[Sweet6]

Whether you do heads and cam will make a big difference in your choice. If the engine is close to stock a 44/49/GT32 are hard to beat. Do fully ported heads and 206 or bigger cam, you could go bigger.

[subsolar0]

Shouldn't I go with something bigger because of my higher stall converter? Or do bigger turbos just make more HP over 20 psi (and less than smaller turbos at 15-17 psi)? I'm willing to pay the extra money for a ball bearing turbo to run bigger and still have a quick spool up. But if it won't make me any faster on pump gas I guess there's no use. Mods are in my signature, but when I rebuild the engine I will also add a Precision Turbo stock location intercooler and maybe 50's or 55's. Car will be drag raced but 99% street driven. I also won't be putting a rollbar so I don't need 25+ psi at the dragstrip. I just want a turbo that will help me keep up with 03-04 Cobras, nitrous LS1's, modified Evo's, etc. I'll probably do ported heads and whatever cam can still pass California emissions.

[Sweet6]

The heads and cam are the main factor on running on 93 octance. If you have stock heads and cam 17PSI is about all you will get out of the turbo. At 17PSI the stock turbo is perfect. If you are dead set on running 93 octance, get an Alky kit. Then you can run over 20lbs no problem. But even at 22lbs a TE44 is what you would want. You could do a 60 with the 3200 stall. But the 44 and 60 turbos are pretty close though.

[TURBOV6]

If you got a 3200-3400 than go with the GT6131e way more potential than the 44. No matter what with 93 you won't see much gains especially at that boost levels.

I run 24lbs on the street with a race chip but this is on 100 unleaded

[TurboTnZ06]

A TE44 would be hard to beat. I went 11's with mine with heads n cam. On the street with some stall you will have instant spoolup.

[subsolar0]

Man, if it's even worse here in California, only 91 octane at the pump!

[Sweet6]

Best bet is Alky kit. There are a lot of ways you can do it, but going fast on straight 91 is going to be expensive. It would be easier to do alky and a 44 or 6131 or some turbo similar to those. Or you need a nice set of heads and a good cam to go fast on 91 or 93 octane.

[subsolar0]

How big of a cam do you think I can go and still pass CA smog? And will any of the aftermarket heads pass emissions, or should I just play it safe and port the stock heads? What about roller rockers and smog? Thanks for your help.

[Sweet6]

Not sure about passing emissions. I do not think roller rockers are worth it for what you are doing. Maybe a CA person will chime in about emissions.

[bison]

Originally Posted by subsolar0

How big of a cam do you think I can go and still pass CA smog? And will any of the aftermarket heads pass emissions, or should I just play it safe and port the stock heads? What about roller rockers and smog? Thanks for your help.

Make sure the heads have a functioning EGR or you will fail NOX emissions tests. There are several TR's on this board that pass CA smog without problems. Make sure you have a good functioning cat converter. Alky injection is not prohibited even in CA, i would be all over it if i were you. Your gas is $hit out there. They had 100octane at a station in HB for ONLY $7.00/gal when i was out there last summer.

[Marc87GN]

Originally Posted by TURBOV6

If you got a 3200-3400 than go with the GT6131e way more potential than the 44. No matter what with 93 you won't see much gains especially at that boost levels.

I run 24lbs on the street with a race chip but this is on 100 unleaded

I agree 100%. I have already raced another GN with a 44 and he was running more boost with alky and I was on straight pump gas at 20-21 psi with the converter locked. Out of the hole he was quicker, but up top I passed him without a problem. The PI 3200 stall sitting in the garage might fix that. There are several guys running 11s with the 44, but probably none on straight 93 octane. The car pulls very hard at 20 psi on 93 octane believe me.

With a 3200-3400, I would go with the PT/GT6152E. I run 3K stall and it lags for a split second then the tires just spin. With 3200+, you better have a real sticky tire out back. Like the guys have mentioned, heads, cam, intercooler and good efficient turbo are needed. My 99 GT with T-76 made many low 11/high 10 second 93 octane.

[subsolar0]

Marc87GN, 20-21 psi on straight pump gas no alchy? Or do you mean 100 octane?

[Marc87GN]

Originally Posted by subsolar0

Marc87GN, 20-21 psi on straight pump gas no alchy? Or do you mean 100 octane?

I pull out of the mobil station by my house with a tank full of 93 octane/no alky and hit 20/21 psi every time I'm out with my car. I owned a turbocharged 99GT that ran 10s on pump gas(well documented in 04/02 MM&FF) so I'm no stranger to a fast car on pump gas. I'm sure I could go alot faster on race gas or with alky, but with the right combination of parts & tuning, a car can be fairly fast on pump gas.

[subsolar0]

Wow, what chip are you using? I didn't know our cars could run such high boost on pump gas. I know the Evo and Cobra guys can, but thought it was from newer technology heads. I'm leaning towards a setup similar to yours.

[Marc87GN]

Originally Posted by subsolar0

Wow, what chip are you using? I didn't know our cars could run such high boost on pump gas. I know the Evo and Cobra guys can, but thought it was from newer technology heads. I'm leaning towards a setup similar to yours.

I'm not going to pretend to say that it's easy or cheap, but it's not impossible. I run the Extender chip and it has been working great. I came up with a plan and setup my car with the intention of running only pump gas. I would really like to see what it does with P&P aluminum heads and 72BB turbo on 93 octane.

[subsolar0]

Let me know how the BB spools up. Do you think my 3200-3400 rpm stall is enough to spool a BB 66? Would a BB66 spool up quicker than a GT6152E?

[salvageV6]

You could easily spool a BB 66 with 3200-3400 stall.

Russ Merritt can spool a 70BB with that stall, probably lots of others as well.

If you're getting heads and cam work go for the 70BB.

[subsolar0]

Is a BB good for a street car? I've heard they get too hot and don't last long.