76gts or gt 42/76

[turboanthoni]

Give some input on the 2 .This will be on a 274 ci stage heads 236 solid roller . All new parts right down to the block .Mostly street race some track time of course! I want to use the tightest converter possible and it'll be a 400 with a break . Ok guys lets hear the ups and the downs!

 

[49-blues]

I think John Wilde may know something about them.

 

[John Wilde]

I think John Wilde may know something about them.

Wow my ears must be ringing.

The GT-42s are great turbos.
We run a set of the GT4202RLs on Chris's Car.

The GT4276 that you are speaking of is rated at 1200HP.
You can get it in a T4 or T6 Thumper Flange.
For the T4 that will work fine in your application you can get it in 4 different exhaust housings.
1.01 AR,1.15 AR, 1.28 AR, 1.44 AR
The GT Series turbos seem to spool fast.
This might be a good choice for your tight converter you would like to run.

The 76GTS is really nice but is smaller. It is rated at 1150HP.
From what I have heard they can have high back pressure if you turn them up. You would probably be ok because the motor is small. The GT42 has a more effecient exhaust turbine in my opinion.
You can get it with the a .81 or .94 AR.

In addition the GT42 was about $200 cheaper the last time I checked.

If I were you I would purchase the GT42.

 

[JZ 97 SS 1500]

GT42-76 = 76GTS. We modify/work with these units ALL the time, they are great units and will make big power. The 76GTS is just a smaller externally sized version of the GT42-76. Small wheels, and actually the 76GTS outspools the GT42 version due to shaft modifications. On your engine it will spool up just fine. We run them on everything from 1.3Liter engines to 400ci engines. Like John mentioned though their is a price difference.

Jose

 

[John Wilde]

GT42-76 = 76GTS. We modify/work with these units ALL the time, they are great units and will make big power. The 76GTS is just a smaller externally sized version of the GT42-76. Small wheels, and actually the 76GTS outspools the GT42 version due to shaft modifications. On your engine it will spool up just fine. We run them on everything from 1.3Liter engines to 400ci engines. Like John mentioned though their is a price difference.

Jose

Thanks Jose, I am guessing the do to the size of the turbine housing on the GT42 that it would have less back pressure than the GTS?
What have your travels shown?

 

[JZ 97 SS 1500]

Yeah the T6 housing does help a bit as well as the larger A/R T4's. The 76GTS turbine shaft is a turned down GT42 shaft. Thats the reason why it spools a little quicker as well.

Also the GT42-76 and GT42-70 and 74 (known as GT4294 and GT4202) are completely different. One uses the stub shaft design, the other is a full length shaft. The stub shaft is actually a heavier design....go figure.

 

[Otto J]

The GT42-76 may be cheaper,But dont forget the $120 flange needed for the intercooler pipe

 

[John Wilde]

Yeah the T6 housing does help a bit as well as the larger A/R T4's. The 76GTS turbine shaft is a turned down GT42 shaft. Thats the reason why it spools a little quicker as well.

Also the GT42-76 and GT42-70 and 74 (known as GT4294 and GT4202) are completely different. One uses the stub shaft design, the other is a full length shaft. The stub shaft is actually a heavier design....go figure.

Thanks for the pictures.
Do you have any with Airwerks wheels you can post?

 

[John Wilde]

The GT42-76 may be cheaper,But dont forget the $120 flange needed for the intercooler pipe

Unless you chop it off.
Please don't ask....

 

[JZ 97 SS 1500]

hehe, yeah you can chop it off.

We do have some with new wheels, but we have decided to start with a fresh chassis that uses a larger shaft and better thrust. We have to many problems with the 42's on high boost on and off throttle setups. Plus we can't use them on our street diesels .

 

[norbs]

Just a quick question, what size intake hose do you need on the gt42? 5"? Also what hp is the gt42 74 rated to? It may make more power on 231 ci that 274 ci, correct?

 

[Otto J]

The overall dimension on the outside of the inlet is 5"
The 42-74 i believe is rated at 1100

 

[John Wilde]

The overall dimension on the outside of the inlet is 5"
The 42-74 i believe is rated at 1100

Otto,

What is the comressor outlet size?

 

[Otto J]

not positive but i beleive the same as a 42-76,The flanged end
If thats waht you are talking about i have a mock up turbo here i can measure.The flange welds around a 3" pipe though.

 

[Trbobuick]

Yeah the T6 housing does help a bit as well as the larger A/R T4's. The 76GTS turbine shaft is a turned down GT42 shaft. Thats the reason why it spools a little quicker as well.

Also the GT42-76 and GT42-70 and 74 (known as GT4294 and GT4202) are completely different. One uses the stub shaft design, the other is a full length shaft. The stub shaft is actually a heavier design....go figure.

Which one uses the stub design ? The 76 or 74?

 

[S2V6RACER]

John the outlet size(OD) of the compressor is more like 3.5". You would need a 3.5" to 3" step hose to make the transition IMHO if you cut off the Vband fitting.


Norbs, the inlet on mine is 5" I have a 4" clay tile pipe x 4" sch 40 no-hub band I ordered from my supplier and took of the metal banding, so it is just a rubber coupler(low profile) and it made a nice transition without the depth of a fernco or silicone adaptor.

The clay tile pipe is thicker in OD then Sch 40.

Brian, I would assume the 76 is a full shaft turbo as it uses a nut not the nut incorporated in the wheel.

 

[chevyII]

not to cut in but what about the 45/76? havent heard anyone using one on a buick.

 

[JZ 97 SS 1500]

Which one uses the stub design ? The 76 or 74?

The 70 and 74 are the GTA/stub units.



The GT45-76 would be a harder unit to spool, since it uses even a bigger turbine wheel design.

Jose

 

[Trbobuick]

Any HP diffrence between the 74 and the 76 ?

So my turbo here : http://pg.photos.yahoo.com/ph/apengineering2/detail?.dir=f821&.dnm=d483.jpg&.src=ph

, is a 72 or 74 and NOT the 76 i paid for ?

Hmmmmmm

 

[Otto J]

Any HP diffrence between the 74 and the 76 ?

So my turbo here : http://pg.photos.yahoo.com/ph/apengineering2/detail?.dir=f821&.dnm=d483.jpg&.src=ph

, is a 72 or 74 and NOT the 76 i paid for ?

Hmmmmmm

Brake out your caliper and measure the outer smaller side wheel diameter and check