you could run pretty much any turbo on an unbuilt motor if you really wanted to but the question is why?
you'll only be able to run it on low boost settings and therefore you've pretty much bought a huge ass turbo for no reason since you can't wind up the boost and use it at its maximum potential.
you'd be better off running a smaller turbo where you can wind up the boost a little higher at a level that's still safe for a stock motor.

 

I seen guys runing 4780 on stock bottom end with built head thos. If you runing hi boost your bottom end will let go soon. I dont see why you want to run this such a big turbo wit low boost. Too lags for you.

 

like everyone else said, what is the point of running a BIG Single if your not going to run HiBoost..... and you'll get spanked by someone with a Small Single on low boost, much less Hiboost, so what would be the point of even running this turbo?

to get spanked by every single car out there on the street? and spool at 5500rpm and also run the risk of blowing up a motor if your not careful

 

From what I've read on some previous threads it seems most if not all the guys with GT47-80's are running them on race gas only. The wastegate spring(s) they are using won't let them boost low enough so no pump gas ....heres something I found from a quick search:

You are in the exact situation I was in about 1 year ago. I had a GT42-76R and ended up swapping out for the GT47-88 and let say there is more lag but a little nitrous will help put an end to lag. I would do it but remember if you want to boost low with pump gas you have to get the .7bar springs on the wastegates or else you will be like me with the 1.4bar springs and the lowest i can boost is 26psi and I have to run 109 unleaded to boost with that lowest setting but the up side is I can boost way past 50psi if needed. Also your decision should be based on what you want out of the car? The GT42-76R is a great daily driver street turbo and the GT47-88 is a great weekend highway monster. Goodluck on your decision.

Same here!
I can't boost less than 36psi either with my HKS GT60mm, it used to be around 32 with the GT47-80. I have tried to plug the compressor straight to the gate and same 36psi. With the same Wastegate and spring I used to run 16Psi with a 67mm turbo. Did some testing too and at 15psi my wastegate opens good too with an airgun.
I don't think two gates would let you run pump gas either. There is not enough back pressure with those turbos to go lower. I might try to even take out the wastegate from the manifold to see what it does. I hope it won't boost!

I have a boost creep issue too. I am running a VWR manifold and GT47-80. I have a Tial 44 WG instead though with a 22 psi spring in it. I creep up to 33 psi with the boost controller off, but still plumbed in. I also tried taking the boost controller off and directly hooking a hose from the turbo housing to the side of the gate. It would still creep pass 30 psi. If I punch it in 2nd gear, it doesnt hit as much boost though...only 22 psi whereas before I would hit pass 30 even in second. The way I see it is if you have a GT47 you might as well only run race fuel because that turbo is more strictly for race, not street driving.

But, I would imagine an HKS 60mm would hold that boost just fine with an HKS header.

What I'd like to know is can you get away with 93+meth with a GT47 for the times you don't want to spend all that money on race gas?

And I'd also like to see some dyno #s and spool-up info on the smaller T6 frame turbos...I think I remember reading SP has a modified GT42-79(?) that'll do 1050whp but I haven't seen a dyno or any logs..

 

Here is the deal with the GT47-80. It is a great turbo for high hp. BUT, you can not run pump gas on this turbo. The amount of air this turbo flows and the psi will not let you. Even at its lowest boost setting. This is what I was told.

Now if you want a high hp street car that can run pump and when the time comes for 1000+whp and race gas, your best bet is the GT42-76 "Swantko Special" that SP offers.

http://www.spracingonline.com/ssptu.html

 

i've seen guys with gt47-80s run them with a built motor. By built motor means rods, pistons, etc. I wonder has anyone run that turbo setup without a built motor. Maybe on low boost? I was wondering if it is even possile without blowing things up left and right. Feel free to burn me guys i was just wondering. Thanks.

god damn noobs....




Lookin for a short cut to keep up with Andrew?

 

Lmao

 

god damn noobs....




Lookin for a short cut to keep up with Andrew?

haha funny, no i wanted to see just being curious. Maybe lets say i wanted to run a stock block for now, low boost maybe next year i would stroke the motor??? who knows. But i was just curious. Thanks guys especially Jerick(sp). Thanks, i still want to see the vid of my car racing the T/A.

 

I had a 47-80 on the stock bottom end. Also ran it on pump gas a couple of times (16-17psi).

Tim

 

I had a 47-80 on the stock bottom end. Also ran it on pump gas a couple of times (16-17psi).

Tim

Interesting. Can you elaborate more. What kind of power were you making at 16-17psi and how were you able to boost that low? Thank you Tim.

 

Interesting. Can you elaborate more. What kind of power were you making at 16-17psi and how were you able to boost that low? Thank you Tim.

Never dynoed that low...Modded SP T6 header, 60mm HKS gate. Could hold 15-16psi, and all the way up to 35psi. Old school HKS EVC EZ.

Tim

 

I've got mine on a stock bottom end right now and it's about useless. The car is set on base boost (about 24psi) and we had to change the cam timing and set the rev limiter at 7200rpm to get it less than 800hp. It's a useless setup to say the least, even in a temporary situation.

You can drive around on this turbo on 93, just shift at 4,000rpms so you don't have any boost

 

I had a 47-80 on the stock bottom end. Also ran it on pump gas a couple of times (16-17psi).

Tim

And exactly how long did you have this on your car Tim?

 

I've got mine on a stock bottom end right now and it's about useless. The car is set on base boost (about 24psi) and we had to change the cam timing and set the rev limiter at 7200rpm to get it less than 800hp. It's a useless setup to say the least, even in a temporary situation.

You can drive around on this turbo on 93, just shift at 4,000rpms so you don't have any boost

Quit being a sissy and rev it out...the motor will hold it.

Tim

 

And exactly how long did you have this on your car Tim?

A year. Would still be running on the stock bottom end had my crank pulley not backed out and take a nice chip out of the keyway on the crank.

Tim

 

^ dam Tim...... i def. need me an aftermarket crank pulley now

 

I had a 47-80 on the stock bottom end. Also ran it on pump gas a couple of times (16-17psi).

Tim

interesting. Is it useless like onelove says?

 

interesting. Is it useless like onelove says?

IMO its not useless...but you'll never reach the full potential of the turbo on a stock bottom end. If you plan to build the motor down the road, then I would say to get the big turbo 1st...if you never plan on building the motor, then stick to something smaller with better spool and lower output.

Tim

 

As a stepping stone until a built motor, I would buy the header needed to run a 47 turbo, but slap on a T6 42 turbo. I had a 42-70 on my old setup and loved it! Then when you have a built motor, you throw on the new turbo and mod your DP and IC pipe a smidge.

Best of both worlds!

 

tru. Thanks for the info guys.

 

good thread. I am looking to go single and now am researching the T6 turbos and kits but the car won't be built for GT47's for a while. Trying to figure out all my options before buying something and then having to do it all over again later. " do it right the 1st f*@%in time "

 

To be perfectly honest, it's pretty easy to sell everything once you go T6. There are always tons of people blowing their stock twins and looking for a quick upgrade to a single. I had offers on my turbo kit the second I mentioned T6, months before I had actually purchased the kit. I'd suggest making sure your EMS / Fuel / Intake/ IC and Piping is all setup for the T6 setup, and then when it comes time you sell your T4 setup at a slight loss and go with the T6 setup. You'll enjoy the car much more, it will make more reliable power for your stock motor on a smaller turbo, and when you put a built motor in you'll enjoy it that much more.

 

Some good information in this thread,all the experts on this set up should chime in with experience and opion.

 

Some good information in this thread,all the experts on this set up should chime in with experience and opion.

Very few people use the GT47-80 on a stock motor, most go build motor and this turbo all at the same time. That was my intentions as well but a delay on my stroker assembly caused me to get bored and throw it on the stock setup.

 

I'll be using stock block and 47-80 in less then 2 wks for a couple monthes until my stroker goes in. If this thread is still alive, I'll give some feedback. IMO, the bottom end should be fine if you reduce the turbo's power and tune VERY conservatively. Of course, if it blows, big deal. My other block is already being built.