Just got back for a.i.r or American intense racing here in Denver. Clint did some work and tuned and dynoed it for me. Great guy very good at what he does.

Car put down 422 rwhp and 426 rwtq n/a.
Numbers are on a dynojet.

It needs better heads and a new intake. But I need to do the rear end first.

Overall super happy with it.

 

Just saw your avatar did you have this car up on eBay for sale awhile back ?

 

Nice dyno numbers! I'd be super happy with that too! Yeah, I think you'd be pushing your luck if you continue to beat on that 10 bolt. What are your plans for the rearend?

 

Yes it was just up on eBay. I just bought it about 2 weeks ago.

yeah the rear is built but I don't think it will hold what it has right now let alone an additional 175 shot of nos. I'm going to go strange s60. I just need to get the swap all finished there are some odd thing that need finished. Just changed the oil pan and the exhaust is cool but not practical and is welded solid and to the frame.

 

Yeah, I was thinking the same thing about the rearend. I was looking at the s60 too. Seems a little more affordable than the alternatives. Sounds like that exhaust is going to fun to fix. Good luck with it.

 

Worst thing about the S60 is no gears taller than 3.54:1. There used to be 3.31:1, but good luck finding a set. A 408 LSx with spray just doesn't need a whole lot of rear gear. Most of your improvement will be in the torque converter. Plus the S60 is heavier and far more money than doing your own Ford 8.8" swap. A 33-spline 8.8" with a rear cover will hold your proposed 600 RWHP, and adds gearing choices of 2.73:1, 3.08:1, 3.27:1 and 3.31:1

 

that seems extremely low... my 364 ci ls2 made 468/440

 

x2
my buddies cammed stage 2.5 headed LS1 made 418 rwhp

 

Those numbers are horrible. My old truck with a 6.0 stock bottom made 470rwhp through a 4l80e and the 14bolt.

 

DENVER guys... ya know.. MILE HIGH.. and all.. sheesh..

 

thanks raver.

as anyone that has 400 plus hp knows its still a fun ride. now that said i surely want more.

couple things holding it back.

1 5280 feet elevation.
2 stock ls6 heads with just comp cam springs
3 stock ls6 intake
4 1 5/8 inch long tubes. not sure how much im leaving on the table here.

big cam without heads is cool but it doesnt make the power it should without the heads.

the heads and cam will be a coming attraction. i need to squeak threw etest and get my rear end and drive shaft upgraded. then its back to the horsepower side of it

 

-3 to 4 percent horsepower per 1000 ft of elevation. On average.

 

Wouldn't the SAE-corrected dyno numbers take elevation (or for that matter, all atmospheric conditions) into account?

 

Yes. Unless they just show observed HP.

 

When I saw your numbers my first reaction was...

Now the low numbers make more sense. It's very common place for a 408 to make 500+ RWHP. Uncork that thing and get some air flow through it.

 

I guess "taller" means different things to different people.

The S60 may be heavier, but it is bolt-in vs. an 8.8 swap. I've only seen comparisons to 9" and 12-bolt, but the S60 is more efficient than either of them (9" being the least efficient).

I can't imagine needing a ratio lower than 3.54 for a track-primary car. A taller tire can be used if necessary. My LS1/T56 car went through the traps at 6000 RPMs with 4.56 gears and 26" tires. If I were to take the car to a lower elevation, I'd put 27" tires on it.

 

I ported a set of 317s for a friend with a 408, made 460 to the ground, ran out of fuel at 6500, stock injectors, I did not have polishing bits, so it was not as I like, polished. Swapped a fast intake and full length headers, made over 500, so I have faith in my porting abilities, lol.