torchz06

I have a c5r 427 with 8.5:1 compression. I am doing a custom single turbo kit on it this winter. I want to make around 700 rwhp. What turbo do you guys think is the best for this setup. PTE 76, 72??? Q-trim, ball bearing?

I am all confused?

Thanks

Evo98z

I would talk to a sponsor that is experienced with turbos first if i were you. There are quite a few knowledgeable turbo guys in here ( me not being one, but am trying to be) and I am sure they can help. I am just saying you are talking about a custom turbo system with a stroker motor, a lot of money is involved, and I am sure you would want the right setup for your combination and goals the first time. IMO

Jammer

iTrader: (1)

forget 700, go for an easy 800-1000 . Call Speed Inc. or John Craig at Limit Engineering.
My opinion, Minimum of an 88, water-cooled, ball bearing.

y2khawk

iTrader: (5)

You'll be much better off with an 80 or 88 than a 76.

The boost level and flow for a 427 and only 700 rwhp will be way outta the useful range of the 76. An 88 will be much happier at that operating point, and leave you some "room" to grow

Shouldn't have any problem spooling it either.

ChrisB

Yeah, I say go for an 88 also.

torchz06

It says on the Precision website that the gt76 ptq will support 975hp so I figured that was probably 800 in real world terms. I have seen some t88 on so supras and the don't spool until 6000 I want the car to be rediculous fast but I still want to be able to drive it on the street with minimal lag. I think the motor will probably only take 15 lbs of boost max because of the head bolt configuration or I will be lifting heads left and right.

Thanks

gator's 99TA

iTrader: (2)

i assume you are going to destroke the motor or allow for some crazy pistons to lower the compression level of a stock c5r?

MYTURBOT/A

The supras only have about half the cubic inches you do. I think rob had a t88 on his 348ci and didnt have any problems with lag, so i think you`ll be ok.

Whistler

iTrader: (46)

You will have no problems spooling an 88MM with 7 liters of engine. The GTQ 76 will make all the power you want, but it will probably spool TOO fast. the 88 will help to keep the power levels usable and will make the CFM you need for 700 HP at a lower inlet temp than a comparable 72 or 76...... more efficient.

Stenod

iTrader: (1)

I say go for the big one! 101 baby, or have some serious sack and go for the 106!!! I don't know, thinking BIG here

Stenod

Noyzee

iTrader: (37)

Big!!!!

Vents

iTrader: (9)

werd Stenod. go big or go home. the 101 gets my vote.

i was thinkin the same thing just before i saw the post. just be sure and open up the AR on the turbine side pretty well, and it'll be pretty insane. i'd LOVE to do something like that.

MIGHTYMOUSE

iTrader: (59)

that 975 is flywheel, which like you say may be 800rw and thats at max psi of 30 or so which you say you want to stay around 15.. i vote 88mm

also FWIW boost is not related to lifting the head, thats cylinder pressure. you can run 30# of boost on these engines and not lift the heads.. admittedly one or more things in the set up are inherently wrong at this point as 30psi SHOULD be at least 900rwhp.

Noyzee

iTrader: (37)

MM, when you heading north so i can by you a beer?
Car almost done?
PS, Id say go 88. Or bigger!!!

Scalpel

iTrader: (4)

What would ~10 lbs put down on a 427 with compression above, great heads and nice cam? Also, would this be a single turbo setup or dual?

torchz06

Hopefully a PTE t76 gtq with a 427 at 10lbs boost it will make 700rwhp with good tuning.

Excal

well..a t-76 kit is good for a STOCK ci car..

T-88 here as well...it would be more efficient, more Drivable perhaps.

eviltwins

Lag with a small-frame T88 is going to be nonexistant. With a .96 tang housing on my friends 383 8:1 compression we were making 18 pounds of boost by around 3600 RPM's. A PT76-GTQ in reality will support more than 900-some-odd horsepower, pretty much all turbos on PTE's site are underrated. They used to rate the PT74 at like 850 horsepower but i've seen over 800 at the wheels with one.

Whistler

iTrader: (46)

The GTQ PT turbos support way more than the website suggests.... as well as having spool characteristics similar to a smaller turbo. With an engine that big in a street car, you will definately want SOME lag. A GTQ 76 MM on a 7 litre LS1 would probably put close to 1000 ft lbs to the wheels by 3500 RPM and be nearly undrivable at WOT. My vote is for the 88. It will make all the power you'll ever want at efficient operating speeds, and if you ever want to turn up the volume and go racing, it will put a 3300 lb car DEEP in the 8s.

zturbo

Well if it was me personally I would look in the 88-91 mm range and shoot for bear. I think that is way way more turbo than your hp goals but will get you there very easily. The one thing I see is that with a 427 ci setup you will spool alot of turbos up very fast. I have a t-100 but would not put aspirations of a street car running this turbo.

A t-76 will achieve your hp goals though if that is what you want. mustang guys have gotten alot more hp out of a t-76 than some think. (Big daddy ran what 8.19 at 189 with a 77.8 mm max size????) I would say that it is very easily going to get your hp wants in your ballpark.

If your going to spend the money for a c5r block and all the goodies might as well get a big turbo (88-91)

You could just buy my 100 and be done though lol

Have fun with the build
Steven