logan2ss

Gap from 586whp to 700whp is quite a bit of distance imo

Rich2342

iTrader: (1)

Thought he said 700 crank. Which would not be far off.

Not many LS7's doing 700 unless stroked, etc.

logan2ss

I thought you might have read past the whp part by accident. Yeah even being very possible, 700 wheel still is not super common to see out of an NA car much less 427ci or less. Trying to keep up with my baby 416...

02EBC5Z06

iTrader: (1)

700 crank in a C6Z would be around 600-620 whp.

logan2ss

I need 12% driveline loss in my life

Ls1Rx-7

iTrader: (4)

that transaxle is efficient, when you have a beefy rear and a driveshaft you lose alot more power unfortunately.

grinder11

iTrader: (1)

I don't know about anyone else, but it sure as Hell makes pretty special power in my book. It's at least 100hp more than my LS7, AND it's built for roadracing, so it has to be reliable. The mere fact that it is dominating its class also says its pretty special.Drag racing is a different story than roadracing. You only need WOT for 10-12 seconds. 720hp that has to last in roadracing is more special than a drag engine. Highest N/A hp LS7 I've seen was in the engine Masters, built by Judson Massengale@SAM-Hope last name spelling is right-was about 100hp more. I doubt very seriously that SAMs engine would be as reliable in road racing. Theres probably not more than 6 guys in the entire country that have the ability to build an LS to the degree Kurt Urban does. He built the first LS powered car in the 6s in the 1/4mile.....over 15 years ago. Ever hear of Mark Carlyle? Urban built his record breaking C6 Corvette engine. I'm not a nutswinger, but I do give credit where its due. If the car is featured on the cover of Hot Rod, and is dominating its class, well, I'd think it speaks for itself. But hey, guess it's not special to many. I only ask what hp YOU are making, and what class you're dominating? Not being a wise ***, but my LS7 isn't dominating anyone. Maybe yours is?

02EBC5Z06

iTrader: (1)

What we are saying is 700-720 crank is roughly 600 wheel. An ls7 can make 550-600 wheel with basically a cam, headers, and a basic head set with no real compression. Do a hair more head work to get the compression up and a bit more cam and you're over 600 wheel with ease.

02EBC5Z06

iTrader: (1)

What does your ls7 make to the wheels? And on what dyno, just because I am curious.

grinder11

iTrader: (1)

Never mentioned wheel hp. But I agree with you. What makes that power level special is the car is thoroughly kicking everyone's *** in its class. It's hard not to make 600hp-650hp with an LS7. But start making North of 700-720@the crank, spinning around 8k, have it hold up, and put an *** whuppin' one everyone.....If it was that easy, we'd ALL be dominating any class we wanted to enter. I'm certainly not, and a vast majority here are not, either. Urban has one Helluva reputation as an engine builder. To do what this car is doing you don't have Bob the Builder throwing together an engine while downing a six pack! To get any engine to be reliable enough to spin 7,000-8,000 rpm for 15 minutes, a half hour, whatever, and dominate, they must be doing something right..

grinder11

iTrader: (1)

Not the topic of the thread, but it made 617hp@6,300rpm, and made around 540 to the wheels on a Mustang dyno. Whatever numbers Im making, Im not dominating anyone, week after week.

It should be noted that I put 7,000-8,000 miles/year on my car. That includes driving it to Florida and back every year, so I stay a bit conservative on it.......

Che70velle

iTrader: (6)

77 hp loss through driveline on a Vette, from engine dyno to chassis dyno…appreciate the data Mike.

02EBC5Z06

iTrader: (1)

Usually seems to be the case up to about 8-900 wheel.

SlowTBSS

Damn I'm envious. My 402 made 670 before adding the vacuum pump and fixing the valvetrain and I was just hoping to crack 550whp in my TBSS. I think this solidifies my idea to find a base C6 and drop my engine in.

02EBC5Z06

iTrader: (1)

What are the details on that engine?

SlowTBSS

402, 11.75:1, Mamo 235 heads, Mamo cam 243/249 .675/.675, YT 10mm rockers and ported LSXRT. Peak RPM was 6650. Makes me wonder how much is left if it was cammed to make peak at say 7200, but it's obvious designed around the heavy SUV.

02EBC5Z06

iTrader: (1)

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Ohh lol Josh, didn't realize it was you. Have to make a new profile?

SlowTBSS

Yeah, long story but I was locked out of all my Google accounts and saved passwords etc.

Either way, 700hp from a 427ci engine, which is 1.63hp/ci really isn't that big of a stretch. God knows the LS7 head architecture can support lots of power. I know there's quite a few threads online with Tony's LS7 heads making 600 and even 650rwhp.

02EBC5Z06

iTrader: (1)

This is exactly my point. I would be livid if I had an ls7 and it DIDN'T make 700+ crank. It is too easy to make that power, and make it reliably.

grinder11

iTrader: (1)

You guys are missing several points. First, its probably at least 625 at the wheels. The BIG point is with enough money anyone can build an LS7 to make this power. The hard part is having it live reliably for more than Joe Blows 10 or 11 second WOT 1/4 mile run. The second part is if anyone can build a reliable, 720hp LS7 road race engine, why is this car kicking everyone's ***? Urban is one of the few guys who knows every trick there is on building motors that make power, win at the highest level, AND dominate competition. It was never about the 720hp LS7. I've seen higher output LS7 motors. But finding reliable power at high rpm for greater time periods is a LOT harder. Dominating your competition is harder still. There's a HUGE difference between winning, and dominating......