427

iTrader: (3)

We did some power runs last night on a stock crate LS7 with dyno headers and a Big Stuff 3 controller....


rpm----tq---hp
3000--455--260
3500--467--311
4000--504--383
4500--526--451
5000--529--503
5500--512--537
6000--480--548
6100--472--548
6200--463--547
6300--454--544
6400--445--543


Kurt

98blackSS

Very nice numbers

Glad to see Scott's motor is in good hands too.. Nice work Kurt.

Bill Reid

iTrader: (14)

Well I guess "505hp" is out the window

Bill

Builder

Ohhhh, baby!

Excellent job, Kurt and John and company. Am I excited? WoooHooo!!!

And thanks for sharing your knowledge, and the extra detail items to make this installation simple.

Can't thank you guys enough. Rides in the Ultima at the speedway when we (the GTR and I) come visit...
__________________
-- Scott
'76 Chevy Lifted 3/4 Ton Built 350 4x4
'96 Chevy Impala SS LT1-4L60E Bolt-Ons, Moog, Hotchkis, BMR, Bilstein's
'05 Ultima GTR - 2200# mid-engine with a 548HP LS7. Pix at http://www.ihp.com

NOSjohn

iTrader: (9)

Hahaha....Scott is flying high ! Looks like that's gonna be a fun motor! Congratulations!

mrr23

iTrader: (3)

they dyno'ed it with headers, not the stock manifolds the motor comes with.

John B

iTrader: (10)

Awesome!!! What are the spec's on the headers? Did you try any different headers? How much timing and what was the A/F at these numbers?

Pumba

Good torque gain over an installed stock package:

Installed Torque at the Crank ~ 483 lb-ft

Installed Horspower at the Crank ~ 533 Hp

.

98blackSS

Scott, you should have Kurt slip in a nice bump stick while he's got it in his hands

Builder

We talked about it a little. However, after driving two of these now, riding in four, and talking with ~35 owners, 550 BHP is going to be WAY PLENTY. That's 4 lbs. per HP in a very steetable package. It's hard enough to get the power to the ground at 2200 lbs. It just smokes the hoops.

That said, you know how it is...more is better! At least, that is my usual line of thinking regarding HP. So, it's still in the back of my mind to turn this into a fire-breather at some point...maybe six months...maybe two years...

A buddy with a GTR has just about all of the parts now and is starting the build of his twin-turbo LS2 (might be an LS6). He plans on making no less than 900 HP and the turbos are good to 1,300. He's headed for the "Silver State Classic" in May.

Maybe you have heard of the Silver State Classic? It's an open-road, timed race over 90 miles of Nevada highway...with no LEOs (!) except for the race officials. They have a dozen speed classes...all the way up to unlimited. There was a guy there a few years ago with a TT LS1 Ultima GTR. It made 1,300 BHP and had a six-speed trans. He took the car to 229 mph in 5th. Backed it down saying it felt like it was getting light. (Please use crow-bar to remove seat from sphincter)

98blackSS

That's cool.. Something you could always do later. I'm sure you'll more than enjoy the power as is.. Can't wait to see it sitting in the GTR.

Kurt, snap some pics of Scott's motor with the BS3 setup if you get time.

427

iTrader: (3)

The headers are 34 inch 1 3/4 with merge collecters hooked to a 3inch bullet muffler. Only ran the one dyno set. Timing was 27.5-30.0 during the run, A/F was around 12.5 average.


Kurt

Phoenix 5.7

iTrader: (7)

only 1 3/4 headers for a 427 ci engine? seems like the headers should be at minimum 1 7/8. that is still extremely impressive numbers

John B

iTrader: (10)

Thanks for the clarification Kurt!

Kurt, did the headers have a "D" port design or round at the port. I've read conflicting stories about what should be used with the "D" port exhaust. Any thoughts you can share here?

Greg Fell

iTrader: (9)

The LS6 heads have "D" shaped ports too...wont the same headers that fit those heads fit the LS7?

John B

iTrader: (10)

Greg, I understand this, however, I lifted the quote below from CorvetteForum.com:

Greg Fell

iTrader: (9)

Hmmm, I wonder what the kooks 1 7/8 will be like, with them. Does anyone know?

Pro Stock John

iTrader: (34)

Slap a cam in that bad boy and tell us the results!

98blackSS

That's what we'll be running..

427

iTrader: (3)

The headers had a standard round port design. The head has a D-shaped exit, but our headers did not block off any part of the port.


Kurt