dyno numbers on the 331.

[slow91]

458hp, 470ft/lb torque on 93 oct and safe tune. not sure why it made all the power at 4700 rpm's and dropped off from there? maybe heat. it was 94deg and 54% humidity

[5150 LX]

What intake you running???

What was the cam designed to "do"??

What valvetrain on the TFS heads??

[slow91]

explorer intake, twisted wedge heads (unported) and a custom cam that is supposed to be good 2000-6000. very reputable cam designer.

[regattacoupe]

Sharp drop in A/F??soft springs?lifters? The exploder intake is probably leaving at least 15hp on the table.

[chemical5l]

did you see my dyno numbers, I made alittle more hp but you have more torque, my blower cam is from comp cams, what 331 kit did you go for, I went for the coast high performance pro street kit.

[slow91]

I read the 5.0 mag couple of weeks ago where they used a holley systemax II on a similar setup and gained 52hp at the wheels. i may try that. local shop is trying it too and said it is a nice peice that needs no port work. anyway the head are new, no idea what springs are in them, whatever trickflow puts in there. lifters are new frp hydraulic rollers.

[slow91]

it was a dyno day for a local stang club and I beat out a lot of setups with vortech s-trims. couple of newer cobras and one with a 347 and a vortech. tuner said it will be over 500 with some race gas and a little more timing. I think i can find a way to get there w/o doing that.

[slow91]

oh, re: the shortblock.....I did most of it myself. probe srs pistons, scat 9000 crank, probe forged i beams, total seal rings....lots of block work. all balanced. cruises like a stock motor. it didn't drop off totally after 4700, just started to fade.

[5150 LX]

here's a couple thoughts.....

Possible spark blow out, you running an aftermarket ignition???

Did you degree in the cam?? If not then maybe it not dialed in where it needs to be to pull to 6k.

Are your heads the track heat or the street versions? If they are the street, depending on your cam specs you may need a spring that'll allow for higher lift (street's are good for .550 lift marginally) Also my box stock TFS heads had a valve job that wasn't worth a crap straight outta the factory, my machinist gave me a real valve job and I upgraded to some ISKY springs to handle my TFS II cam.

The explorer intake really isn't a solid performer, there are much better options especially for s/c applications.....but it still should not fall off like that.

[slow91]

yes I have an msd in there. plugs gapped at .036, box stock tw's, the streets, not the track heat version. cam is .512/.512 and duration is 284/294. designed for a 331 s/c, ground by Erson. along with the intake, thought about adding a water/alcohol injection boost cooler. heard some good things about those. I wonder if they pulled too much timing off the top because I had blown a hg a couple of months ago.

[slow91]

i'm an idiot...read graph wrong. torque maxed at 4700, hp maxed at 5500.

[blown5oh]

I would think that you'd make more power - in the 500 range w/ the 331. The cam and the intake are holding you back, I'd think.

[slow91]

I agree. i'm saving for a systemax intake now. thinking about 1.7 rockers to help the cam out a little but i'm not sure if the stock trickflow springs can handle it.

[Doug]

I'm sorry, but there is something amiss in your combo. The intake is really hurting you. How much total timing are you running? What injectors? FMU or not?

These are my old combo numbers. It was a stock 302, AFR165 heads, Track heat intake, stock cam, through an AOD with a Novi 2K(stock pulleys). There is no reason why a 302 should outpower your 331 combo.

[slow91]

well your blower is 1700 cfm to my 1050 n1k. the intake is hurting me, its a good midrange n/a intake. i'm changing to a blower intake soon. also the tuner pulled out some timing but i don't know what the total timing is now. its noticably slower since the "safe" tune. it was pretty nasty before. he told me to get some race fuel and he'll put some timing back in and should be 500rwhp. a/f is 12.05. oh, and it was 94deg and humid that day.