Fox 329 HP low for a stroker?

[Andresquintana.mma]

Hey everyone just got my car tuned last week and got my dyno sheet back and had 329 hp and 336 TQ. I posted it on a facebook group for fox bodies and everyone was saying that was low for what I had done to the engine. Everyone was saying I should make at least 400 to the wheels. Is my car underperforming? If so what can I do to get my numbers up?
1993 Ford Mustang GT 347 stroker w forged internals, Comp cams custom ground cam, tfs 205 heads, Holley Systemax intake II, 30 lb injectors, Anderson 3.5 power pipe, 70 or 75 mm throttle body, bbk long tube headers, bbk x pipe, flowmaster 40 series mufflers. Thanks in advance everyone figured Id ask the experts here.

 

[Scrapla347]

Nice build. I have a NA 347 stroker making 325 rwhp and 395 ft lbs. I have a Trick Flow Street Heat upper and lower, Edelbrock Performer RPM heads, 42lb injectors, custom grind cam (not sure the specs), Anderson Powerpipe and an Accufab 75mm TB. When I got my car tuned it was just to make it safe to drive and daily, we didn't squeeze out all the power but my tuner (Scott Beers formally with DiabloSport) said there was a lot more to go but I didn't have the cash at the time. I still have the custome tune chip in my A9L. I get comments all the time how low on power mine is but they love the torque.

 

[Andresquintana.mma]

Nice build. I have a NA 347 stroker making 325 rwhp and 395 ft lbs. I have a Trick Flow Street Heat upper and lower, Edelbrock Performer RPM heads, 42lb injectors, custom grind cam (not sure the specs), Anderson Powerpipe and an Accufab 75mm TB. When I got my car tuned it was just to make it safe to drive and daily, we didn't squeeze out all the power but my tuner (Scott Beers formally with DiabloSport) said there was a lot more to go but I didn't have the cash at the time. I still have the custome tune chip in my A9L. I get comments all the time how low on power mine is but they love the torque.

Thank you! Yeah you have almost 60 more Tq than me, wonder whats going on w my setup. We are pretty close in setup! Good job though man really loving the car just would squeeze more out of it if its there you know! Ive been driving mine daily w no problems starts up easy very driveable, its a blast!

 

[Monkeybutt2000]

Stock ecu? Untuned?

 

[Andresquintana.mma]

Stock ecu? Untuned?

A9L tuned

 

[FastDriver]

One time I had my car tuned at HPP racing in Dallas texas. Manny, the owner, tuned it to about 660 wheel horsepower. I told him that seemed awfully low, considering it had dynoed well over 700 before. He gave me some conciliatory 'Heartbreaker dyno' comment. After thinking on it for about a night, I did the math and it was making about 7/8 of what it should have. A day after I informed him of it, he found an injector that was improperly connected. The car made 729rwhp on the next pull. He said he'd never seen one missing like that without it being obvious, before. Even though they were the ones that tore it down for new gaskets and pulled apart and reconnected the injector harness, being who they are, he still charged me for both dynos and the work to diagnose and fix their own F-up. Oh yeah, and it took 'em a year and a half. Life was just too busy for me back then, but no shop will ever do me like that, again. I'd sooner do it all myself, these days.

Anyways, some dynos are misleading, why don't ya get on the track and see how it traps? What altitude are you at? Maybe pull the plugs and inspect to ensure all cylinders are firing? I do think 320s is low for that setup, but I also know the dyno can throw things off.

On the tuning front, that AFR needs to be leaned a tad to closer to 13:1, typically. Widebands can be off, but the plugs will tell the tale. What's the WOT timing curve?

Just some ideas...

 

[Andresquintana.mma]

One time I had my car tuned at HPP racing in Dallas texas. Manny, the owner, tuned it to about 660 wheel horsepower. I told him that seemed awfully low, considering it had dynoed well over 700 before. He gave me some conciliatory 'Heartbreaker dyno' comment. After thinking on it for about a night, I did the math and it was making about 7/8 of what it should have. A day after I informed him of it, he found an injector that was improperly connected. The car made 729rwhp on the next pull. He said he'd never seen one missing like that without it being obvious, before. Even though they were the ones that tore it down for new gaskets and pulled apart and reconnected the injector harness, being who they are, he still charged me for both dynos and the work to diagnose and fix their own F-up. Oh yeah, and it took 'em a year and a half. Life was just too busy for me back then, but no shop will ever do me like that, again. I'd sooner do it all myself, these days.

Anyways, some dynos are misleading, why don't ya get on the track and see how it traps? What altitude are you at? Maybe pull the plugs and inspect to ensure all cylinders are firing? I do thing 320s is low for that setup, but I also know the dyno can throw things off.

On the tuning front, that AFR needs to be leaned a tad to closer to 13:1, typically. Widebands can be off, but the plugs will tell the tale. What's the WOT timing curve?

Just some ideas...

That can be a possibility, tuners swapped plugs for me so they are new for sure. Ill double check my connectors to the injectors Thank you! Cant believe they charged you for their mess up smh. Id be so made for a year and a half on top of that thankfully mine wasnt even gone for a full week.
Id like to take it to the track, Im a total newbie in the 1/4 mile but got to start somewhere.
Im also at 5500 ft but I was told on fb that the dyno factors in the altitude, Im running trickflow heads. Idk if they would be the sane as afrs?
Not to sure the timing curve at WOT how would I look that up do i need access to the tune file to see it? Ive always been a backyard mechanic this is only the 2nd car I tuned.

 

[AeroCoupe]

331 in my coupe makes right at 370ish to the wheels on a Mustang dyno. I’ve always heard that a Dynojet dyno will show more than a Mustang dyno but never have made pulls on both with the same combo. The motor made right at 460 fwhp and 430 ft-lb of torque on an engine dyno. This was at higher rpm’s than what you pulled.

I would say it’s not making what I would have thought it would for that build sheet but the torque is more than mine.

 

[Noobz347]

Air/fuel looks good. If it runs good and has good street manners, I wouldn't care too much about the dyno number. If you want [more], boost it.


The dyno graph does beg the question:

"Why is it falling off at the top when peak torque doesn't kick in until almost 5000 RPM?"

There is a bottle-neck someplace or the cam is just not up to snuff.

The other possibility is that the Dyno is not up to snuff. What's the deal with the spike in the graph?

 

[Scrapla347]

Thank you! Yeah you have almost 60 more Tq than me, wonder whats going on w my setup. We are pretty close in setup! Good job though man really loving the car just would squeeze more out of it if its there you know! Ive been driving mine daily w no problems starts up easy very driveable, its a blast!

I'm happy where my car is at because I don't race it. I'll never forget that feeling after it was tuned and feeling how hard it pulled like that feeling you get on a roller coaster. I'm happy but everyone would make the same comment "That's all it makes?" My engine builder was a family friend Eddie Miller who owned The Engine Works. He was all about torque and always told me don't sweat the HP numbers because torque wins races.

 

[Mcmahst]

This is a formula I had in my notes from a performance community college class from the 1970’s. Take it for what it is:

HP Loss= elevation x .03 x HP @ Sea Level

5500’ will have an effect on the output, NA. Maybe ask the dyno operator to give you both the corrected and uncorrected sheets from your run. Good luck.

 

[FastDriver]

Another thought, doesn't a Systemax run 1250 ports, while the TFS 205s are on a 1262? Some port matching there and ensuring the right TB size might really help.

To answer your question on timing, yeah, if the tuner used anything other than a simple dizzy turn to adjust base timing, then you'd need access to the tune file. How did he tune it? If it's a .bin file, send it to me, and I'll take a look for you.

 

[limp]

I'm happy where my car is at because I don't race it. I'll never forget that feeling after it was tuned and feeling how hard it pulled like that feeling you get on a roller coaster. I'm happy but everyone would make the same comment "That's all it makes?" My engine builder was a family friend Eddie Miller who owned The Engine Works. He was all about torque and always told me don't sweat the HP numbers because torque wins races.

Torque wins on the street...

 

[Scrapla347]

Torque wins on the street...

Yea and that's all I drive it on. My first gear is pretty useless. I didn't plan on having a motor built I sort of just fell into it.

 

[Noobz347]

He was all about torque and always told me don't sweat the HP numbers because torque wins races.

I think he an I are of the same religion:

On a Side Note: I had mentioned to somebody in this forum, the oil separator I have inline of the oil filler neck.
Whoever you are... Here's an image of it.

 

[AeroCoupe]

@Noobz347

Engine Post in thread 'Read my plugs'

Mar 24, 2025

I run something similar to this:

Husky 3/8 in. Standard Poly Bowl Filter HDA70603AV - The Home Depot

Husky - 3/8 in. Standard Poly Bowl Filter - This poly bowl filter is designed to keep air lines maintained, helping to remove unwanted dirt particles larger than 5 microns, as well as condensed water.

www.homedepot.com

I've removed the internal [filter stone] because they're irrelevant for my purpose.

Initially, I put one in-line of the filler neck and one in-line for my PCV. It was a bit restrictive on the PCV side so I added another in parallel to increase the volume.

For what these cost now; You're probably better off with a good catch can on the PCV side and maybe one of these for the filler neck.
(This setup is what I'll be going to next for various reasons that...

• Noobz347

 

[nickyb]

Hey everyone just got my car tuned last week and got my dyno sheet back and had 329 hp and 336 TQ. I posted it on a facebook group for fox bodies and everyone was saying that was low for what I had done to the engine. Everyone was saying I should make at least 400 to the wheels. Is my car underperforming? If so what can I do to get my numbers up?
1993 Ford Mustang GT 347 stroker w forged internals, Comp cams custom ground cam, tfs 205 heads, Holley Systemax intake II, 30 lb injectors, Anderson 3.5 power pipe, 70 or 75 mm throttle body, bbk long tube headers, bbk x pipe, flowmaster 40 series mufflers. Thanks in advance everyone figured Id ask the experts here.

I've always heard you loose 15% of flywheel h.p. to rear wheel h.p. with a manual trans and 20% with an auto trans.
A good bench mark is blueprint engines 347, mild cam and compression makes 415 flywheel h.p.

 

[FastDriver]

Did the OP mention whether it's auto or manual? A loose convertor can make a pretty big difference, too.

I'd like to know more about the cam, too. I don't see why in the world TFS 205s + a Systemax is anywhere near that. My AFR headed 331 made 362 without a tune at 8.5:1 compression.

 

[TOOLOW91]

Did the OP mention whether it's auto or manual? A loose convertor can make a pretty big difference, too.

I'd like to know more about the cam, too. I don't see why in the world TFS 205s + a Systemax is anywhere near that. My AFR headed 331 made 362 without a tune at 8.5:1 compression.

I’d venture to say intake is untouched like you said. Not saying that’s where all the power is but I’m sure it’s worth something

 

[Scrapla347]

I think he an I are of the same religion:

On a Side Note: I had mentioned to somebody in this forum, the oil separator I have inline of the oil filler neck.
Whoever you are... Here's an image of it.

The builder was Eddie Miller from The Engine Works here in South Florida. He had a NA purple Duster and use to compete in Drag Week back when it started around 05 or 06.