thinking of buying a GT3255 turbo

[Marc87GN]

With the mods I have, I'm able to run 18-20 psi on straight 93 with zero knock. How much power should I gain over the stock turbo @ 18-20 psi with the GT3255 turbo?

I would get a TA 49 or Te 44, but everyone runs those so I'm planning on the Turbonetics Cheetah Stage V W/Ceramic bearing or the GT3255.

 

[lieu910]

GM High Tech did a comparison with the GT turbos and they seemed to perform slightly better. Without completely commiting myself to that debate, I would say the pwer increase at the boost level you stated would be only marginal regardless od if you choose a ta-49 or the GT.

I was on the fence recently between those turbos also, but fortunately a friend bought a PT-61 and let me drive his car. I was really impressed and bought that turbo.

The PT-61 would be my reccomendation to you. There is room to grow with it and it costs basically the same. I bought mine from PT and they utilize the GT compressor in the 61.

I think others will agree that you may be disappointed if you buy a ta-49 and run it at 18 psi expecting noticeably more power than stock. I think the sweet spot on those are around 24-25 psi??

 

[2QUIK6]

If you are sticking with the stock stall convertor, then you are limited to either the 49,44, or 3255. If you are open to getting a higher stall, then for street strip, the 61 can't be beat IMO. There are different variation of the 61 out there. The PT61 is the most popular and requires 3200 stall. I have a variation of it with a smaller exhaust wheel and mine runs well with a 2700 stall, but would be perfect with a 3k stall, and you may run out of injector quickly too with a 61, I'd say 50's at least unless running a 7th injector or alky.

 

[Marc87GN]

I appreciate the information. I notice that the inexpensive way to go is run high boost (stuffing 20 lbs of poop in a 10 lb bag), but that is not my approach. I have decided to spend the money on a Stage 3 port job from VPE. have heard of cars running over 110 mph with the stock turbo with P&P heads at 15-16 psi.

I can only imagine how fast I could go with a PT61 @ 16 psi through heads flowing over 200 cfm on the intake side and the exhaust flowing in the 170s . I would think the car would be trapping mid 1 teens on pump gas without a sweat.

 

[lieu910]

Originally posted by Marc87GN
I appreciate the information. I notice that the inexpensive way to go is run high boost (stuffing 20 lbs of poop in a 10 lb bag), but that is not my approach. I have decided to spend the money on a Stage 3 port job from VPE. have heard of cars running over 110 mph with the stock turbo with P&P heads at 15-16 psi.

I can only imagine how fast I could go with a PT61 @ 16 psi through heads flowing over 200 cfm on the intake side and the exhaust flowing in the 170s . I would think the car would be trapping mid 1 teens on pump gas without a sweat.

Marc,

I think that is a good approach. The more you can do on just motor the better I think. Opens up many possibilities when you do want to make the leap to a bigger turbo.

Remember though, 20lbs of boost or even 25lbs is really nothing to be too concerned about as long as the car is tuned properly and running the proper fuel.

Good luck.

 

[2QUIK6]

P&P the heads is definitly and big advantage to be able to run faster with less strain on the head gaskets with less boost, but 400-500hp is 400-500 hp on the crank either way, so the bottom end needs to be up to snuff no matter how you do it. It's amazing to me that all of the f-body folks bypass porting and doing alot of head work and go straight to a SC or turbo saying there is no advantage of porting heads on a SC or turbo application.

 

[John Wilde]

Originally posted by Marc87GN
With the mods I have, I'm able to run 18-20 psi on straight 93 with zero knock. How much power should I gain over the stock turbo @ 18-20 psi with the GT3255 turbo?

I would get a TA 49 or Te 44, but everyone runs those so I'm planning on the Turbonetics Cheetah Stage V W/Ceramic bearing or the GT3255.

What timing do you run?

 

[JDSfastGN]

Marc what times are you wanting to run in your car? Just curious as thats a big part of my recomendation. The 3255 is a good turbo and so is a 44 and 49. When i first got my 44 i thought i made a mistake and should have gone bigger but after slowly widdleing away at my track times i realized it was perfect for my combo without pushing the limits of the motor. I'm positive my car will go 11.teens or even 11.00s with a little more work, my last time to the track resulted in a 96 mph run in the 1/8 through a tranny with the pump going out and at the top of the run it blew both headgaskets because of the convertor becoming very inefficient and taggin the limiter. Anyways its gone 11.93 at 113 on drag radials on pump gas and 11.68 at 113 on slicks and pump gas (17-18 psi) if that gives you any idea. If you want more or want to not have to push it so hard for similar number i don't think you can go wrong with a PT61 or 61 varient with the GT wheels.

 

[Marc87GN]

Re: Re: thinking of buying a GT3255 turbo

Originally posted by John Wilde
What timing do you run?

19 - 1,2 & 17 3,4

 

[Marc87GN]

Originally posted by JDSfastGN
Marc what times are you wanting to run in your car? Just curious as thats a big part of my recomendation. The 3255 is a good turbo and so is a 44 and 49. When i first got my 44 i thought i made a mistake and should have gone bigger but after slowly widdleing away at my track times i realized it was perfect for my combo without pushing the limits of the motor. I'm positive my car will go 11.teens or even 11.00s with a little more work, my last time to the track resulted in a 96 mph run in the 1/8 through a tranny with the pump going out and at the top of the run it blew both headgaskets because of the convertor becoming very inefficient and taggin the limiter. Anyways its gone 11.93 at 113 on drag radials on pump gas and 11.68 at 113 on slicks and pump gas (17-18 psi) if that gives you any idea. If you want more or want to not have to push it so hard for similar number i don't think you can go wrong with a PT61 or 61 varient with the GT wheels.

Damn, those times and trap you have are perfect. That's what I'm looking for. high 11s or low 12s @ 112-115 on straight 93 octane so I could drive from NY to florida and still have a fast car on pump. Agressive has the PT61 on sale, but then I need a converter so I have to spend additional money. i think P&P heads wit hthe GT3255 should be enough to hit high 11s on pump gas only. Based on your setup.

 

[azgn]

Originally posted by Marc87GN
I appreciate the information. I notice that the inexpensive way to go is run high boost (stuffing 20 lbs of poop in a 10 lb bag), but that is not my approach. I have decided to spend the money on a Stage 3 port job from VPE. have heard of cars running over 110 mph with the stock turbo with P&P heads at 15-16 psi.

I can only imagine how fast I could go with a PT61 @ 16 psi through heads flowing over 200 cfm on the intake side and the exhaust flowing in the 170s . I would think the car would be trapping mid 1 teens on pump gas without a sweat.

more flow=more power= more octane required at any given boost level

you won't be able to run 16 psi on well flowing heads with straight 93...your car is octane (and timing) limited

better flow may lower your charge temps and allow you to make a bit more power but I sure wouldn't count on 11's with straight pump gas with just ported heads and a bigger turbo......if it was that easy, guess we would all do it?

who needs race gas or alky?

 

[Marc87GN]

Originally posted by azgn
more flow=more power= more octane required at any given boost level

you won't be able to run 16 psi on well flowing heads with straight 93...your car is octane (and timing) limited

better flow may lower your charge temps and allow you to make a bit more power but I sure wouldn't count on 11's with straight pump gas with just ported heads and a bigger turbo......if it was that easy, guess we would all do it?

who needs race gas or alky?

I would imagine most people don't do it because it's more expensive and alot more work. If you are not pulling and re-installing the heads yourself, I can see how that could get costly. I have seen several people run 11s without alky or race gas. cooler air charge means less chance of detonation.

More efficient turbo, much better flowing heads and intake should be enough hit 11s or damn close to it. Cam and/or better rockers may do the trick. I also have a decent supporting cast of mods.

 

[azgn]

I expect my car would easily run 11's on straight pump gas (at prolly 10 lbs of boost), but it is built to run low 10's on race gas

the point I was trying to make is increased efficiency in your motor will indeed make more power and you may not be able to take advantage without better fuel

good luck with your goals

 

[Marc87GN]

Originally posted by azgn
more flow=more power= more octane required at any given boost level

you won't be able to run 16 psi on well flowing heads with straight 93...your car is octane (and timing) limited

I believe that would be more flow=more fuel=more power. If the air is cooler why would I need more octane. More fuel, but not more octane. This isn't my first turbo car. It's the first one with the poorest flowing heads I have ever seen. I put a T-76 on my 99 GT. Much more flow, much more power(than the S-trim) still on 93 octane.

I agree I won't get the most out of it, but this car won't see the track and will be driven 2000 miles or less a year.

 

[sixgun86gn]

Originally posted by azgn
more flow=more power= more octane required at any given boost level

you won't be able to run 16 psi on well flowing heads with straight 93...your car is octane (and timing) limited

better flow may lower your charge temps and allow you to make a bit more power but I sure wouldn't count on 11's with straight pump gas with just ported heads and a bigger turbo......if it was that easy, guess we would all do it?

who needs race gas or alky?

I don't know about this.I had my car with a te63,3200 stall,pp heads and 218/218 cam running 7.1 in the 1/8 @100 on 93 and took it to the 1/4 track and was able to run in the 11.2s @121 or so consistently on just 93.Boost was only 16#

Oh and it was summertime here too when I was doing it.Consistently.

 

[Louie L.]

Originally posted by azgn
I expect my car would easily run 11's on straight pump gas (at prolly 10 lbs of boost), but it is built to run low 10's on race gas

the point I was trying to make is increased efficiency in your motor will indeed make more power and you may not be able to take advantage without better fuel

good luck with your goals

Kinda off subject but not really. My car ran a string of 11oh-11.30s on 12-14 psi while we were testing the boost controller. So your car would be deep in the 11s on 10psi...

 

[silverT-PA]

11's on 93 easy????

what part of the country are you running?
i'am from the north east.not to many buicks running 11's on pump gas around here.it gets cold up here and we hibernate during the winter giving everybody else extra time to mess with there cars...
mike s

 

[sixgun86gn]

Texas here 100* summers.

 

[Robbie-87plz]

Nice article done up here on Louie Lopez...could ya give us some insight as to GT-60 series race fuel vs 93? Nice car....

http://gmhightechperformance.com/tech/0411htp_turbo/