Horsepower disappointment

cheese_05_70

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Aug 29, 2005
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I got my car dynoed and tuned and it only put out 256hp and 285tq.

Ithink them number are extremely low. I have:
306 motor
vic sr. heads 2.02/1.60
1.6 rockers
E-303 cam
Typhoon intake
Hooker super comp shorties
2.5 o/r h-pipe
24lb inj
75 bullet pro-m
255lph in tank

I need some cat back exhaust right now i got 2.25 flowmasters on it
thanks for any comments
 
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I'm sure I'm not gonna be helpful here.. Sorry! But, My understanding is:

You want to match all your upper end parts with the same "brand" OR Atleast have them ported to match each others "flow and what not"..!?!

So, maybe your "parts" aren't matching up to each others "potential flow/HP"!?!

Just a "newbies" guess.....
 
At 18% loss due to drive train thats 302 hp at the flywheel. Not bad with a tune on your ECC you will find more i am sure. Your 2.25 exhaust is killing topend for sure. Have a tuner make a chip for your ECC and I am sure those numbers will be higher. BTW the E cam isnt a hugh HP maker thats why its 50 state EPA approved. Its even CARB approved so that should tell you something.
 
Well, those are pretty big intake valves for an unstroked engine. Plus, the cam is pretty small for the size heads you're running, and there are better intakes you could have with the heads and a better cam. I think the problem (besides the smallish exhaust) is mismatched parts.
 
Well, those are pretty big intake valves for an unstroked engine. Plus, the cam is pretty small for the size heads you're running, and there are better intakes you could have with the heads and a better cam. I think the problem (besides the smallish exhaust) is mismatched parts.

I agree... heads are a litlle big.... and the cam is too small. An e-cam works well on a bone stock motor. IMO
 
I have a similar setup to cheeseo0570 except my heads are 1.90"/ 1.60". Would my numbers be the same? I think my only weak point is my 110 fuel pump. Comments anyone?


IMO, you may be a little stronger than his. The reason is port velocity. When you have huge intake valves, the air moving through them goes slower. Without having more cubic inches to increase the demand (in other words the intake of air into a larger cylinder) the air moves into the engine slower resulting in lower numbers. That plus a cam that isn't up to par with the heads and you get so-so performance. Having huge heads or any part that's overkill for your combo often means you're going to lose more power than you'd gain. It would be like throwing a huge cam into a stock engine...it may sound cool but that's about all you'll get out of it.
 
I think the numbers are about right for your set-up. Your still about 60rwhp more than a stock 302. your probably not high compression and a you have a mild mistmatched hci. Btw what kind of a dyno was it? There are hp/tq differences between a Dynojet and say a Superflow & Mustang dyno because the latter 2 are loading dyno's, they will give lower numbers.
 
To clear up some confusion everything is:
gaskget matched
heads are port and polished
it is tuned with a chip
and it was on a dynojet

what kind of cam would someone recommend? What about putting 1.72 rockers on what I got now or just putting 1.7's on the exhaust side? The reason I say that is because all the flow numbers I have seen are low on the exhaust side?

Thanks
Colby
 
Those valves are fine on a 306....i had the Trickflows with valves the same size. I would get better intake. Whats your throttlebody size? What is your timing set at?

I had almost the same setup except trickflow heads and intake and a 70mm TB. It made good power. Your heads are fine. Just a bit more aggressive cam and trickflow/ systemax intake and you'll make more hp. Headers are the most restrictive. I don't think you'll see too much of a gain by changing rest.
 
IMO I would step up to a bigger cam or go back to 19lbs injectors. I have never understood why people choose to tun 24lbs'ers on engines that are pretty much stock. Now if you bump the cam size up quite a bit you could use the 24lbs'ers

Ummm.....He has victor heads an aftermarket cam and intake, nothing stock there. Are you running it through an AOD or T5? That'll make a bit of difference. Also, what was your a/f ratio during the run? scan that dyno sheet and post it
 
Bottom line is, you need more cam and more intake to match the heads. Get those and you're still going to see your peak numbers up close to 6k or beyond with those heads. I'd look for a cam with at least .550 lift and at least a 285 advertised duration.
 
Thanks for the info. My power started to already drop off at 5500rpms. The tuner said it was because the exhaust after the cat. He said with the exhaust it would pull alot higher therefore make more power.
He also said the sniffer was in the back of my exahust thats why the a/f ratio is so high.
Info is greatly appreciated. This was my budget build while going to college. I got 1100 in this combo which I dont think is too bad.
Im going to try and attach the dyno sheet.

Yea the dyno sheet didnt work very good. sorry
 

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Ummm.....He has victor heads an aftermarket cam and intake, nothing stock there. Are you running it through an AOD or T5? That'll make a bit of difference. Also, what was your a/f ratio during the run? scan that dyno sheet and post it


Heads and intake are nothing without a good cam. He's running a E-cam. Thats like 1/2 step above stock. It's still a smog cam so yeah IMO that's pretty much a stock cam in my book. Victor heads on a pretty much stock bore. I know it's a 306 but 4 extra cubes are'nt that much. Thats just to much valve for such a tiny cam. I think he would make alot more useable power on the low end if he bolted the stock heads back on with that cam. With those heads i think the comp cam with 565 lift. That would work alot better with those heads. Put it on the bottle and watch out. With just going to that cam i would guess he would be looking at 325HP