Do the dyno numbers make sense for my 331 now????

juiced_94gt

Active Member
Mar 30, 2005
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Southern California
Ok last year when I tuned my 331 combo in the sig. it made 315 RWHP and 345RWTQ but I was under the assumption that I had flat top pistons, now I just found out that I have DISHED (I can supercharge now:rolleyes:) pistons, with AFR 185's with a 61cc combustion chamber, 1011-2 fel-pro HG's and 14.2cc dish vol. pistons do my numbers make a little more sense?? or is it still low?? Since the tuner thought I had flat tops would he have tuned it different??:shrug:
 
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I made 355rwhp/365rwtq with my 8.89:1 compression 331 with AFR 165's, my old FTI cam that was for my stock shortblock combo, and a holley systemax intake. I don't want to bring you down but I think your numbers were still pretty low, even with the low compression.
 
I think the numbers are still a little low but more in line with what they should be. I think a custom cam and a holley intake would help the numbers alot. Personally from the dyno comparisons I've seen on the Trickflow track heat intakes I'm not a big fan of them. I've just not seen many good numbers from them.

Alot of people like them though and I have no personal experience with them so this is just a opinion.

Here is one of the reasons for my thought on the intake in the link. There is a dyno comparison between a explorer intake and a track heat. http://www.tmossporting.com/tabid/3451/Default.aspx

On another dyno comparison between a tfs track heat and a holley systemax the systemax made 360hp and the track heat made 336. That test is on this website under tech articles. http://www.andersonfordmotorsport.com/
 
Using a 4.100" diameter headgasket and .040" headgasket, piston .010" in the hole, I got 9.308:1.

How far is the piston in the hole?

What headgasket are you running?

I will run it through PipeMax again.

Numbers still are low. A custom camshaft would help a lot.
 
I think your numbers are good considering the off the shelf components you are using. Paul's car is somewhat freakish (IMO) so don't get too depressed. What kind of dyno was it? (mustang or regular)

Have you performed a compression test? How high are you spinning the motor? Post a dyno chart and we'll comment. (I love dyno charts)

Adam
 
Hey juiced a couple things.
1. Your intake is deffinately hurting your numbers.
2. a custom cam would help, but in my opinion not to pauls levels, unless you do cam and intake.
3. Steve's dyno at powertrain dynamics shows numbers lower than 2 other dyno's my car has been on (this is after he tuned it for me) This does not upset me in the least, both other dyno days asked what I "thought" the car produced, both times I was low by at least 15-20.
4. The tune does not have much to do with domed or flat top pistons, he tunes for driveability, A/F ratio, and overall spark. So in essence hes using those numbers to tune, not comp ratio. (there's a lot more to it than that but a tune has more to do with those values than Comp ratio) The higher comp ratio would cause detonation, unless a higher octane gas is being used, so if there was no pinging and the A/F and timing is correct, you should be good.
I'm obviously not a tuner, but these are the thing I always look and listen for.

I personally dont care that much about HP numbers, their fun to throw around, but thats all. I brag about the TQ the car makes, for a small displacement small block it makes a boatload of TQ, and thats way more fun to me on the street. Dont get me wrong I love top speed, probably more than the next guy, but I really love the thrill of the acceleration up to that speed.

Hope that may clear up some things for ya. Also if you want to get a dyno run on a different dyno i'll give you a couple shops close that charge a fair price for just dyno runs.