My Comp Cams and GT350 manifold results (spoiler alert: it's not good)

jcart953 said:

^Do you have a dyno sheet lol I love to see it. You can PM me if you want.

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yes

As you know Mustangs typically read lower than Dynojets, and can read much lower depending in the shop and how they set it up.

Racered's graph reads STD, which is a few % higher than the more commonly used SAE correction factor. Since his power is still increasing, he would likely make more peak power with a higher redline. Why did you cut the run short from the stock 6,80/rpm redline?

Ford says the GT350 IM (power pak 3) makes 60hp more than stock at 7,500rpm -where the stock intake is choking and severely dropping in power. I don't think the 350IM is simply a bolt-on 30whp increase.

Eritas said:

As you know Mustangs typically read lower than Dynojets, and can read much lower depending in the shop and how they set it up.

Racered's graph reads STD, which is a few % higher than the more commonly used SAE correction factor. Since his power is still increasing, he would likely make more peak power with a higher redline. Why did you cut the run short from the stock 6,80/rpm redline?

Ford says the GT350 IM (power pak 3) makes 60hp more than stock at 7,500rpm -where the stock intake is choking and severely dropping in power. I don't think the 350IM is simply a bolt-on 30whp increase.

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Im actually not sure about why they cut out earlier than redline, it was a VW/Audi shop that did the dyno and they probably weren't familiar with mustangs, they work on my gli and are the closest place with a dyno. So youre right, i probably would have had a higher peak power.

It probably didnt help that it was a 95 degree day with about 70% humidity and my intake temps were about 107 and i just drove 55 mins from my work to get there :frusty:

Did you have a baseline run?

Oh My quick googling skills says if you multiply the STD rwhp by .974 you can get closer to SAE numbers. I think it assumes certain "standard correction numbers though".

jcart953 said:

Did you have a baseline run?

Oh My quick googling skills says if you multiply the STD rwhp by .974 you can get closer to SAE numbers. I think it assumes certain "standard correction numbers though".

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nah i didnt, i should have though, but i knew i was only going to do basic bolts ons before going FI anyway so i didnt even think about it.

Im assuming if it would have been taken to the actual redline with SAE correction i could have been 420-425whp which is what i expected anyway. Honestly didnt even realize it was in STD till someone said something, im glad it was pointed out or i would have never noticed lol

Just a quick update: I picked up the car this morning and drove it home. I couldn't really get on it though because it was raining a little. It certainly has more usable RPM, which is great. Feels a little more sluggish down low, but I'm sure some of that is me looking for it.

I decided to make an appointment to put it on a Dynojet to see if the results from before are repeatable on a different dyno. I know, I know, different dynos, different days, etc., but if this shows a deficit of power down low too (and a lower peak than expected), then I know that it wasn't just that there was an issue with the first dyno. If that's the case (which it probably will be), I'll likely put the stock cams back in, take my losses and move on...

Did you end up reusing your stock springs, or did you replace them with the cams?

Do you have a datalog? I would like the see your injector duty. Also, did you have wideband hooked up during the run? I've always been under the impression that with a manifold upgrade that you need to upgrade injectors.

Eritas said:

As you know Mustangs typically read lower than Dynojets, and can read much lower depending in the shop and how they set it up.

Racered's graph reads STD, which is a few % higher than the more commonly used SAE correction factor. Since his power is still increasing, he would likely make more peak power with a higher redline. Why did you cut the run short from the stock 6,80/rpm redline?

Ford says the GT350 IM (power pak 3) makes 60hp more than stock at 7,500rpm -where the stock intake is choking and severely dropping in power. I don't think the 350IM is simply a bolt-on 30whp increase.

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Excellent point. I can really feel the strong pull of the 350 mani above 6500. That's where it really gets good.

Dragster said:

Just a quick update: I picked up the car this morning and drove it home. I couldn't really get on it though because it was raining a little. It certainly has more usable RPM, which is great. Feels a little more sluggish down low, but I'm sure some of that is me looking for it.

I decided to make an appointment to put it on a Dynojet to see if the results from before are repeatable on a different dyno. I know, I know, different dynos, different days, etc., but if this shows a deficit of power down low too (and a lower peak than expected), then I know that it wasn't just that there was an issue with the first dyno. If that's the case (which it probably will be), I'll likely put the stock cams back in, take my losses and move on...

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Good call, keep us updated with the Dynojet results!

Out of curiosity, what peak numbers would you find acceptable for your set up? I know you'll be looking throughout the entire powerband but as far as peak power goes what would you be expecting?

HISSMAN said:

I've always been under the impression that with a manifold upgrade that you need to upgrade injectors.

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I think Lund is fine with the stock injectors with the GT350 mani so long as you're running 91/93. E85 requires the injector upgrade.

racered_ppGT said:

nah i didnt, i should have though, but i knew i was only going to do basic bolts ons before going FI anyway so i didnt even think about it.

Im assuming if it would have been taken to the actual redline with SAE correction i could have been 420-425whp which is what i expected anyway. Honestly didnt even realize it was in STD till someone said something, im glad it was pointed out or i would have never noticed lol

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Correct, but rev it it and it'll make more than that

I hate that GT350 intake......

Could had a Cobra Jet IM......

I'll keep an eye on this and hope you get it sorted out.

Edit step 1. would be find a different tuner.

Step 2. punt that intake!

Side note Id rather run stock intake and cams than stock cams and and different IM.

The cams are in now for the love of god dont go back to stock cams.

If nothing else Id buy a CJ intake and get some tuning advice from [MENTION=28009]Evil 5.0[/MENTION]

Did you end up reusing your stock springs, or did you replace them with the cams?

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I kept the stock springs. I believe Comp states that you don't need to replace the springs.

Do you have a datalog? I would like the see your injector duty. Also, did you have wideband hooked up during the run? I've always been under the impression that with a manifold upgrade that you need to upgrade injectors.

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I do have a datalog. I don't know if a wideband was hooked up during the run as I wasn't there (I had to drop off the car); I assume that the only data being checked was what was recorded on the Ngauge. Lund stated that the stock injectors are fine, unless I wanted to run E85.

Out of curiosity, what peak numbers would you find acceptable for your set up? I know you'll be looking throughout the entire powerband but as far as peak power goes what would you be expecting?

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I suppose that the peak probably won't be that far off what I was expecting. I was hoping for a little over 460 rwhp (Dynojet numbers). Still seems odd to only gain ~20 hp from cams and a manifold, though... Right now my concern is more about the loss of power below 6,000 RPM. I figured it would probably lose 10-20 lb-ft of torque below 4000-4500, but from the graph it looks like it lost ~40 to nearly 5,000.

I hate that GT350 intake......

Could had a Cobra Jet IM......

I'll keep an eye on this and hope you get it sorted out.

Edit step 1. would be find a different tuner.

Step 2. punt that intake!

Side note Id rather run stock intake and cams than stock cams and and different IM.

The cams are in now for the love of god dont go back to stock cams.

If nothing else Id buy a CJ intake and get some tuning advice from @Evil 5.0

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I didn't want to mess with cutting the hood or lowering the engine and losing the strut tower brace. Based on the mods the car has, it looks like the cams are the culprit for losing all the power down low, not the manifold. Yes, the CJ would be better with those cams, but hindsight is 20/20... Had it had only a small loss in power, I wound't be so concerned.

I am making 458whp with a similar setup on stock cams but catless and e85. That is dynojet SAE numbers. If you make 470+ on 93 on a dyno jet SAE then I believe there is nothing wrong. Switch to a CJ mani and you will be closer to the 500whp mark and e85 or race fuel would of course help as well. Don't put the stock cams back in, they are proven by several people to help achieve your goals. Have some patience to sort it out, definitely get it on a dynojet and see what you get. Its a good sign that you are seeing 50lbs per min as long as your fuel trims aren't off. Lund tunes some of the fastest Stangs on the planet, they know what their doing. Especially with a remote tune instead of email tune.

Stock TB and Intake could be the instigator you are using a 80mm TB going from that to 87mm should be a noticeable difference.