Low Power Numbers On 10 To 1 347.... ?!?!?!?

[vpap1]

ok here is the particulars,

347 10 to 1 short block from coast high peformance
track heat top end kit with stage 2 cam
80 mm maf
75 mm tb trickflow
bbk shorty headers
no cat h pipe
4o series flowmasters
true trac posi, 31 spine mosers
rear upper and lower control arms
3.73 gears
upgraded coil and distrib chip
dyno tune made 282 at the wheels

reccomended a griffin radiator cuz it was pinging at the top of the gear, motor is fresh ie less than 5 miles on it, new clutch, fly,

tranny has trouble shifting and is being replaced, is that enough to cause the low numbers????

its a reputable shop as well, Dez Racing

any ideas? or weak points in the combo?

V

 

[Mr. Rustypwnz]

wow thats low, that cam really needs to be degreed +2-4 advanced to take advantage of it. We did 350+rwhp on a 306 with vic jr's and a tfs stage 2 on a R intake. It made no power at ALL just throwing the cam in, we degreed it and it was about a 50rwhp gain, and still made peak hp at 6800rpm.

I would do the following:

get a better intake manifold, its too small to make the "best" power on a 347, go with a tfs R manifold, you should be able to sell the other and offset the cost.

Shorty headers are not alot better than stock, definately get some 1 7/8 longtubes, thats 20+ hp right there.

And degree the cam! You will not run into ptv issues either with those heads.

 

[vpap1]

it has a bum tranny, very hard to shift, has 2x cold nitrous spark plugs, would these be a cause to rob power? ordered a tko 500 so i i have virtually no money for improvements. I can ask the tuner to check the cam degree i guess

V

 

[reldla1996]

At what RPM did peak power occur? How fast did the peak power drop off? What was the peak torque, and at what RPM did it occur? Bad valve springs can lead to low hp numbers, but you would not expect that with everything new. It's hard to imagine a manual transmission causing a large power loss. What size are the headers and exhaust? Where is the timing set at? What electronic tuning has been done, or none? What was the air fuel ratio at peak power, and at higher RPM's? What size are the injectors and fuel pump? 282 rwhp equates to roughly 325 hp at the flywheel; what were you expecting?

 

[vpap1]

well all i heard was the actually dyno number i wont have the car for another week or so. Headers are bbk shorty headers i think 1 5/8", 2.5 exhaust, it has a full dyno tune and timing at the chain was 0, not sure of the electronic specifics. 30 # injectors and 255lph fuel pump. I feel it should have been in the 320 rwhp area

V

 

[srtthis]

what kinda dyno?

 

[vpap1]

Dyno jet!

 

[srtthis]

ouch....
id start playing with the tune NA before trying to spray it (if thats why it had such cold plugs in it)

 

[vpap1]

Well that was just a guess, but I'm sure they are still in there. Ditched the nitrous and gonna go NA after all.
V

 

[vpap1]

Should I take it back and drive it to break all the new parts In And see if she loosens up? Then dyno again?
V

 

[srtthis]

i know you said its a new build but id still run a compression check and leak down test to double check everything is good.

 

[vpap1]

well i'll get her back and break her in and will do a compression test and check the basics

V

 

[Rick 91GT]

Those numbers are way low....like said start by checking everything, including valve lash. Ive build 331 and 347 combos that would put atleast another 100hp to the wheels.

 

[vpap1]

Agreed when I get it back I will go through the top end and check degree of the cam.
V