95 cobra: 331/AFR/procharger going to dyno

Hi all,

Finally dropped my 95 cobra off to a local tuner on a flatbed last weekend for initial start up, as well as completing a dyno tune with an SCT chip: Maryland Performance Center Car should be dynoed early to mid next week.

Wanted to get opinions of what this car might see on the dyno.

Dart 331 8.9:1 compression, forged internals
AFR185 heads with matching springs to cam
Edelbrock RPM II upper/lower manifolds
Custom cam
PMAS 3" pro tube
MSD 50# injectors ( Flowed 55lb when tested )
Glenn's 1000hp fuel system
FMS 65mm throttle body
Procharger D1SC, 3.7" blower pulley, 7.00" crank
1 3/4" MAC shorty headers
3" MAC Prochamber
3" Magnaflow catback
Tremec TKO
full MSD ignition
other supporting components

Idea is to tune the car with what is has, then planning to go back to re-dyno in the up and coming months with an AFM power pipe, and a larger throttle body, as well as larger injectors if need be.
I'd like to get some ideas of what this car might be capable of seeing or if anyone has a similar setup that I have?

Point of reference:
Old combo of stock 302 shortblock, GT40X heads, E303, cobra upper/lower, and D1SC @13psi made high 490's to the tires with Larocca tune.

Yep, so it's a Comp Cams roller, with Crane 1.6 rockers. Here are a few specs:

Lift: .574 intake, .545 Exhaust
Adv duration: 274 intake, 285 exhaust
Lobe sep: 114.0

We should only be revving the motor to 6500rpm, if I don't get too much belt slip on the 6 rib procharger setup. Will be running 93 pump gas.

BlackVert said:

you'll be lucky if you get all the way up to 300 at the wheels

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That's 300 more than it's making now. So, that would be a start..

Thanks for helping to set expectations. I just dropped off the 7" crank pulley to replace the 6.75". Hoping this allows the car to see another 2-3lbs of boost, and also help the boost come on quicker.

Update: the car was strapped to the dyno on Friday but isn't entirely finished with the tune. The tuner apparently had some issues with the cobra J4J1 computer, and took nearly all day to get it to where it is. I will have more numbers hopefully on Tuesday afternoon/evening when it is entirely finished.
Thus far, on a Superflow dyno, it made 510rwhp @6200rpm, with 10-11lbs of boost and about 24 degrees of timing. The 6.75" crank pulley has not been changed out for the 7" as of yet, which should yield a few more lbs of boost.
A few years ago I had the car dyno'ed on a Dynojet where it made 455rwhp @10lbs, and 495rwhp at 13lbs. It had: stock 302 rotating assembly, GT40X heads, E-303, stock cobra upper/lower, full exhaust, D1SC.

I would be curious to see how my current numbers would change on a Dynojet compared to the Superflow dyno. Just to compare apples to apples.

Rookie71 said:

Sounds healthy. Good luck.

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Thanks. I should know more tomorrow if there are any updates on the tune. I'm due to pick it up as well, but with all of the heavy rain we're due to receive in Maryland, I think I will wait a few days.
I'm also considering to take the car to a Dynojet facility just to get some base line numbers, since the car was previously dyno'ed strictly on Dynojet's at Larocca's. I'd like to compare apples to apples to see how much power I picked up, even though I've been told the Superflow is a better indication of real world horsepower.

Don't have the dyno sheet in hand, but here is the bottom line:


Made 510rwhp @ 6200rpm on about 11lbs of boost on the Superflow dyno.
Car is running a conservative 11:2 A/F ratio, with a total of 24 degrees timing. I feel the timing was a little aggressive, however, the tuner mentioned I was picking up nearly 30rwhp per every 2 degrees of timing, so the car liked more timing, but I personally am not comfortable with more than this.

I also had a few concerns which I will iron out with another tuner who has more experience, as I don't believe this tuner has very much knowledge with the 94-95 Cobra J4J1 ECU, as it took him a full business day of dyno tuning to "figure out" the J4J1 computer.

Here are my concerns:

I questioned from the beginning ( prior to having the car worked on and tuned ), that I wasn't certain if the MSD 50# injectors would be large enough for this combination. I was assured they were, and would be good to 800hp. Sometimes it's just not worth it to argue with someone over something like this.

-He, the tuner, mentioned that during the tuning session, my Pro-M 3" pro-tube pegged at 5V by 5400rpm, which I found very hard to believe, considering this meter can handle MUCH more power. The tuner explained that he fooled the ECU into believing the meter was not pegged.

-I called Pro-M to ask their advice on the meter, as well as injectors. After speaking with Pro-M the following day, they confirmed the reason the meter probably pegged, was because I was out of injector, and that the meter was obtaining the reading from the injectors it is calibrated for.

- I'm not a tuning expert by any means, however, I would have thought that after 15-16 years, there should be plenty of resourceful information out there on the J4J1 ECU. I'm wondering how good this tune really is.

-My previous combination was: Stock 302 shortblock, GT40X heads, E-303 with 1.72 rockers, equal length headers, full exhaust, stock cobra upper with mildly ported lower, D1SC with 13psi showing at 6200rpm. In this form, the car made about 490rwhp on a dynojet with 22 degrees of total timing tuned at Larocca's.
My concern with this, is that I'm only showing about a 20rwhp increase in peak power, albeit I'm on a Superflow dyno with this new combination of:

8.9:1 331
AFR 185 heads
custom cam with matching springs
RPM II upper/lower
seeing about 11psi at 6200rpm.

I know the motor had a leakdown test ( albeit new ) a few months ago when it was put on the motor dyno, and all cylinders were well within healthy range. The motor has not ran since, other than to be dyno tuned, so I'm certain the motor is in healthy shape.

Does the Superflow dyno make that much of a difference between the Dynojet numbers I've seen in the past? I was expecting at least a 70rwhp gain after the tune was dial in, by going with better and larger parts.
I'm not sure if I should be concerned yet, until I actually get it on a Dynojet to compare apples to apples...

VibrantRedGT said:

Your not making very much more than you did with the 302 and that's concerning. I'd say it should be making over 565HP right now at a minimum. I agree that your dyno tuner guy doesn't know enough to tie all your parts together. You mentioned earlier in this thread LaRocca tuned your 302 package. I'd go back to him since he knows what he's doing. That meter and injector shouldn't be pegged right now. Both are good for a lot more supporting HP than 510. I'd take the car to LaRocca, reset everything and let him tune it. I guarantee he gets the most out of that combo.

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I would love to have Jimmy retune my car, but he's out of the business now, as far as I'm aware. There is a place in Dillsburg PA that I've been looking at who has a good reputation for tuning mustangs in general. They're formally Kauffman's Performance, and are now called DGR performance: DGR Performance - Specializing in GM and Ford Installs, Tuning, Fabrication, Conversions. Dave Guy does the tuning, and he's reputed to know mustangs well.

I've also been doing a bit of research on the Superflow dyno's, and see that they can sometimes show about 10% lower than a Dynojet, depending on how the owner/operator of the Superflow has they're dyno calibrated. At this point, I'm hoping their numbers are 8-10% lower than a Dynojet, which would mean I'm in the 550-560rwhp, where I would have thought I'd be. Perhaps it's all in the dyno and the tune? If the car was at this power level, that may also explain the injectors. JMO.

FastDriver said:

wait wait... I don't know why, but I kept thinking you'd be seeing 15 psi. I take back what I said about the timing. It's not that bad for 10 psi.

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Right now I'm seeing about 11-12psi by 6200rpm. I'll have to verify the fuel pressure as well. I would *think* with the Superflow dyno and it's ability to apply load via an eddy brake, that detonation would have been detected, which obviously is a concern of mine.
The rest of the fuel system is:
Glenns 1000hp system: dual walbro's, and aeromotive regulator, with glenn's fuel rails, -8 dual feed lines, and one -8 return line.
I also have an MSD 6AL box with MSD distributor and coil.

As of now, I'm planning just to get a base dyno pull done on a Dynojet with a tuner I have more faith in ( such as DGR ), and have an A/F ratio reading completed, so that I can see for myself what kind of power I gained, as well as monitor the A/F again. I also have a big feeling the inlet of the supercharger is really being restricted, as the filter is smashed up pretty bad, and needs to have another solution implemented.
Next spring is when I want to turn things loose with more boost, and perhaps down the road a methanol injection kit. But first, I feel as though I need to know what I'm dealing with now, as I'm not entirely satisfied with how things turned out.

Thanks for everyone's replies.