I am thinking about throwing my Vortec heads, a dual plane intake and a 650 cfm carb on my L98 before the end of the racing season as well as shorty headers.

I plan on upgrading my valvetrain this winter, but already have the rest of these parts and am tempted to perform this swap before the last September race day.

Thoughts? Any guesses on how much horsepower this would make compared to the 230 hp stock? I was thinking in the 300 horsepower range...

 

Putting the stickers on from the parts will, by themselves, add at least 500 HP.

 

Bump, has nobody done intake/heads and left the stock shortblock alone on an L98?

 

Bench racing is already inaccurate enough, but it's WAY tougher without some specs on these parts. Just to be clear, "dual plane" isn't a spec. But, Watajob is totally right. I just put on a sticker from my Summit Racing Carburetor, my Weiand Street Warrior intake, my Quick Fuel pressure regulator, some Hooker Headers, and a Comp Cams valve train, and I'll be damned if that didn't wake my motor right up....

Edit: Just put the sticker on from my Moog Chassis Parts ball joints. No word on how it handles yet, will let you know when the control arms aren't held up with jackstands tomorrow.

 

OK how about Quick Fuel 650 cfm or equivalent carb, Summit Racing stage 1 intake manifold, 906 casting vortec heads, 10:1 compression, 1 5/8" hedman shorty headers.

Just looking for a ballpark, I was guessing between the heads, headers and lack of TPI restriction, somewhere in the low 300 horsepower range. I was hoping for more feedback hopefully the details help.

For the record I drag race, my current best ET is 14.67 @ 94.5 mph, so I estimate my car to have right around 230 to 240 horsepower. I am hoping this new combo will run 13s and mph over 100.

 

I think it could make 300 on the barstool, but if you dyno that, I expect you'll probably see something in the neighborhood of 40-50 hp gain. I do know that losing the TPI manifold isn't going to net you as much as I got when I ditched the TBI turd, but those factory exhaust manifolds were AWFUL! Speaking of which, do you have a smog pump on this motor? If so, I suggest deleting it while you're at it, it's a stupidly simple job. That should free up a horse or three, not much, but it's cheap and makes more space.

Remember, horsepower is only cheap when you have sponsors, and stickers weigh less than paint. I heard from a rally car builder on a TV documentary that they save 8 lbs on the Ford Focus by using stickers to cover it instead of paint.

 

For god's sake,pay to have it dyno'ed for tuning. Anything else is baseless.

 

 

I see your point, however I think the strip is a great "real world" option as well. I see a wide variance in dyno #'s, especially chassis dynos, however the strip gives you an ET and a MPH. Unless you are correcting those numbers yourself for altitude, they shouldn't lie. Making jetting/timing changes at the strip and running back to back in test and tune is a great tool as well.

I think I started this thread off on the wrong foot by asking about horsepower. In reality, all I care about is a fun street/strip car that runs 100+ in the 1/4 in the 13's. I asked about horsepower because this is the Tech / General engine forum, not Organized Drag Racing. I thought I would get more responses phrasing it that way.

I am not interested in bench racing, but more interested in making sure I will get the results I want without swapping camshafts this go around.