nadrepadre

At my school on the last day of a particular course we were able to dyno our cars. At first my stang only put down 222hp and I almost crapped myself. Bumped the timing up a bit and made 255hp and 299 tq. My combo is in my sig. When I converted my old 302 to mass air, the A9L came with a jet performance chip on it for a stock 302. I actually forgot it was in there and ended up having it on there for the 351w dyno pulls. Would this really hurt the performance this much? Peak HP was at 4700 rpms, peak TQ was at 4100 rpms. I have a somewhat conservative cam at 512 lift, 214/218 duration at 50. I have 1.7 rocker arms so its .544 lift at the valve. I was hoping to be closer to 300hp and figured something must be drastically wrong. Anything jump out at you guys?

351w 9.2:1 CR, windsor sr. heads, comp cams xe264, 1.7RR, professional products typhoon intake, 24lb injectors. All through a t5

uedlose

is that compression right or is that what the piston mfg. said they would be with this head and with the piston this far in the hole with said gasket or did you cc everything out and come up with this. What size T/B and mass air? where was the cam installed or did you just line up the dots? and yes the cam is very conservative. What headers are on it? what exhaust? Did you try moving the F/P around? what were the A/F numbers? there is a lot of unanswered thing gone here. It does sound a bit light but that was RWHP right?

nadrepadre

The compression ratio was what the piston manufacturer said it would be with 64cc chambers and a .040 gasket. On my timing chain the crank sprocket had 3 different notches for the keyway. They notch I used said it would be in the factory position. Apparently it can be advanced up to 4 degrees. Throttle body is the factory 5.0 ho TB. I know I have to get one, but i figured for the sake of the dyno pull I would only loose about 10hp from it. MAF is an 80mm unit that is calibrated for 24 lb injectors. Messed with the fuel pressure and it didn't seem to make a difference. I'm kicking myself because I didn't know we had a wideband o2 sensor in the dyno and it could have told me what was going on. All the way up to about 6000 rpms I didn't hear any detonation or pinging of any sort so I doubt its getting leaned out too much.

oh yeah, this is RWHP.

I was thinking that my cam duration is way to low and thats killing me in the higher rpms. BBK shorty headers, bbk off road h pipe, flowmaster mufflers.

Venomantidote95

Well your school isnt NTI in NC by anychance is it?

The stock 58mm TB is like you being chocked by a noose!

get a 70mm tb and you`d gain 20hp prolly!

air and fuel makes power, you didnt get any det because it was prolly rich, lack of air induction!

you have 351cu in feed it like a fat kid! the 24`s will prolly have to go also!

Your prolly making 300hp at the crank! to get it at the wheels you`d have to be making more like 360hp to the crank!

rethink air and fuel then you`d prolly get much closer to your goal!

Get a flow chart on your heads, see where your cam lift falls in the max flowing lift of the head Im thinking about (.550) and if need be get another cam! you can use a smaller lift cam for your heads if you only off by .015-.020in lift by subing duration but you dont have enough with your current cam! You definatly have the cam maxed out with the cu in and heads!

nadrepadre

so some 30lb injectors, TB, and a bigger cam would probably do it right? my school is UTI in Exton, PA

uedlose

So with the piston mfg. saying the compression is what ever it is. Is this with the piston at 0 deck or is that with the piston in the hole .010. When you put the engine together where was the piston at 10 in the hole was even with the deck or was it even more in the hole you need to know this. for proper compression calculations. If they say it is lets say 9.5 with the piston at 0 deck and your pistons 15 in the hole that is a 1/2 point in compression http://www.csgnetwork.com/compcalc.html see if this helps you out to see what I am saying. 1/2 point don't sound like much but for a engine with what I would call low compression it will make a difference that I think you would feel. By all means get a bigger T/B on that thing. You may need bigger inj. but I would not jump on that yet till you get some real A/F readings but like said you will probably need them and camshaft sure would help things a lot

nadrepadre

ok thanks for the help guys. gave me some good stuff to look at.

Venomantidote95

Depending on your actual C/R you dont want to get to crazy with the duration on the cam! mostlikely itll be around 9.5!

You have to know 5 key elements to figure it right!

but more than likely itll be 9.5 or less with your setup!

with 351W id say no less than 24`s and that might lean out higher in the rpm range!

N/A you should be under peak duty cycle with the 24`s depending on FP!

tb, the right cam and injector you`ll see your goal! if not you will be small numbers from it!

I went to NTI in NC they offered the same dyno runup after the end of the auto tech program also! i had my son and had to come back home to bama and went to an aviation based tech college!

pkrpro

For your poor choice of parts, I'd say it's about right. You really dont have a good combo, rather a conglomeration of stuff.

I got a recipe for 400rwhp out of a flat top 351, but I doubt u want to change everything.

nadrepadre

The only thing wrong with it is the cam. Not nearly enough duration. Plus I had the stock 58 mm throttle body on it. I don't see whats wrong with iron heads and hypereutectic pistons. Not all of us can afford forged and domed pistons, h-beam rods, and a set of a AFR 225s