Hey Guys, I had my dyno shop fine tune my new Holley HP system on the dyno. First off this is a nitrous motor, so really to me it is what it is as far as N/A dyno numbers go. Track times mean more to me than dyno numbers. But I haven't dynoed it in close to 15 years. It made 579rwhp and 558 rwtq on engine. One thing to consider is it had slicks on it which lower dyno numbers considerably. The dyno guy said they had a 1000rwhp car with slicks redyno it just changing to street tires. It picked up 120hp. So he said mine would really be around 630rwhp on street tires.
One thing we found really interesting, I have reached the limits of the miniram… actually surpassed it. My Miniram was ported by Tony Mamo and flows 410cfm. So at our high elevation, the kpa should be at 87 during WOT. if it's less than that, then it's building vacuum in the intake which means there is a restriction on the intake side. A common problem would be a plugged air filter. The vacuum should drop to 0 at WOT. Mine the kpa went to 85 then dropped to 82 at WOT. We took off the whole air intake system. Same thing. So with nothing in front of the throttle body it's building vacuum in the intake manifold. I have a monoblade on it which flows 1350cfm. I think the plenum of the intake and the throttle body has now become a restriction. At this point, I would have to get something like a Hogan sheetmetal intake with a LSX 102mm TB to correct it. But that's $4000, and we don't have a race track anymore. So I will probably leave it as is. It's a nitrous car, and ran 9.78@146 the way it is. So I think I can live with it. But the dyno guy is a pretty sharp guy, seemed to think it could pick up 50hp with a intake and throttle body set up that was optimized.
The Miniram worked good up to 450CI, but 468CI it can't keep up.

 

Very, very, VERY nice!!!

 

Well done! Is that a remote oil filter way over on the drivers side?

 

Yes. I'm using a Dart tall deck block. And there is no provision on the block for a oil filter

 

I've always been curious how you get much over 400ci out of a "SBC" motor? I've heard of what?....409's? Now you're up to a 468...and still calling it a small block? How is that accomplished and/or how to aftermarket blocks improve on GM's design?

Not looking for a novel here...just a quick blurb maybe? Thx!

Of course, now that I've been the token PITA....NICE NUMBERS! Without a track, what's the function of this car? I assume it's never street driven?

 

Great numbers Jim!

Hopefully you can get it to a track.

Steve

 

So with a tall deck block, you can use more stroke... the crank centerline to head mating surface is longer... a stock 350 block is hard to get past like 396 or so... a 400 block you can get around 427 iirc. Having the taller deck let's you get away with it.

It's a small block based block but the height is taller and the cam location is changed iirc as well as a few other go fast mods to improve it. It is still roughly small block sized.

 

This 468 has a 4.185 bore and a 4.250 stroke. The cam is raised .391, and the pan rails are spread .800 so you have better rod clearance. The deck height is .300 taller

 

Its still a street car. I drive it on the street. Still has a full interior. I was running a 300 shot of nitrous at the track, and jetted it down to a 250 shot, which is about the smallest shot you can use with a direct port nitrous system

 

Way to go Jim. Les told me your motor is running well. Nice numbers. Bet you're sleeping better!

 

Thanks Willie, I think its running the best it has

 

Let’s tow it out to Sonoma and see it run 8’s!

 

Next step is 1000 hp

 

Beefy!

 

I'll second that motion! Do it!!!

 

I dont know if would go 8s at a good sea level track, but would probably go deep in the 9s

 

Hopefully you can get it to a track before the season is over.

Car looks great in the photos and nice mount for the Holley EFI.

Steve

 

Jim if a trip to Ca leads you down our way you got a place as long as you need it.

 

Holy Crap....if you could row your own into the 8's....