[leeklm]

Dyno days are usually fun, so thought I would post my latest tweaks... Some thought I was a little crazy tearing down a perfectly strong running motor, but winters are long in MN and the trans needed to come out anyway. And this particular winter does not want to end!!!

For comparison, five years on original build with around 500 drag runs and handful of street miles. Specs in my signature, which at the time ran 585hp on the dyno, but was definitely running stronger with additional tuning and intake porting over the years. Lets estimate 595-600.

I picked up the attached solid roller cam from a fellow member and had the heads opened up to around 325-330cfm and upgrade springs as needed. Running the same worked T2 intake w/2" open spacer. Best HP at 35-36 deg timing.

On a side note, bearings and cylinders looked like new on tear down, so this was essentially done for entertainment purposes and a few extra horses. Threw in a new set of bearings, used a dingle ball hone on cylinders and installed the SD Performance lifter bore braces.

Attached is a run using my 1.75" Hedman headers and a run using Darbys 2" headers with adapter plates. I am happy with results and looking forward to seeing the on track results!

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[steve25]

Great new numbers !
What compression is the motor?

Some observations.

Your old combo used 308 cfm to make that 635 Hp.

Your new combo used 311 cfm to make that 641 hp, so you pretty much have the heads tapped out now.

That being said I think the main improvement came by means of the 2” headers allowing a 4 to 5% increase in peak exh flow numbers.

I bet the 1.750” headers matched your exh port flange area very closely, so the bigger 2” tubes then not only helped to increase the flow by means of pressure recovery, but they helped with reducing reversion.

This action can be seen in the near 20 ft pound gain in torque down at 4100 rpm over the 1.750” tubes.

You can also see the reduction in reversion between the two down at that same 4100 rpm in the fact that the BSFC numbers are just about the same.

Although the test did not go below 4100 rpm if it did you would see that the new combo will have much more torque and throttle response on the street.

From the massive amount of rework I have done in the passed on T2 intakes I can tell you that with your 2” headers and intake flow numbers now that the T2 your running is now the cork in your overall flow tract .
If you where looking for more Hp a 1050 Dominator, even used with your T2 would give you 12 to 15 more numbers up top.

Springs finally here, enjoy having a heavy right foot!

[leeklm]

Thanks Steve,,

compression at 10.5, running BP 93 0ctane. I am somewhat stuck with the 1.75' headers, as it looks like a real pita to find or make 2" dport headers for a 1st gen.

I think that will be ok, as I may be flirting with the 10.0 mark on good air day. Running full exhuast, etc at Norwalk last year I was running a consistent 10.4 with the old faithful cam. Best prior et with open headers was a 10.29 in good air. My guess for the new combo is a 9.99 for that end of year hero run. I may be bolting lead in the trunk lol.

I have zero desire for a certified cage and the other goodies at this point.

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[PAUL K]

Great job! Stout numbers!

[slowbird]

That's great!! Thanks for sharing

[Dragncar]

Originally Posted by leeklm

Dyno days are usually fun, so thought I would post my latest tweaks... Some thought I was a little crazy tearing down a perfectly strong running motor, but winters are long in MN and the trans needed to come out anyway. And this particular winter does not want to end!!!

For comparison, five years on original build with around 500 drag runs and handful of street miles. Specs in my signature, which at the time ran 585hp on the dyno, but was definitely running stronger with additional tuning and intake porting over the years. Lets estimate 595-600.

I picked up the attached solid roller cam from a fellow member and had the heads opened up to around 325-330cfm and upgrade springs as needed. Running the same worked T2 intake w/2" open spacer. Best HP at 35-36 deg timing.

On a side note, bearings and cylinders looked like new on tear down, so this was essentially done for entertainment purposes and a few extra horses. Threw in a new set of bearings, used a dingle ball hone on cylinders and installed the SD Performance lifter bore braces.

Attached is a run using my 1.75" Hedman headers and a run using Darbys 2" headers with adapter plates. I am happy with results and looking forward to seeing the on track results!

Sent from my SM-G965U using Tapatalk

Nice numbers.
Your cam is close to the one I had reground at Bullet.
What is you CR ?

[AG]

Looks like 10.1 ET using 3300# and 636 Hp. Your cam is a tiny bit bigger than mine.

[Scott Stoneburg]

Nice gains, you should be knocking at the 10.0 numbers.

[prostreet64]

Well done. I am sure you will be pleased with your next trip to the track. And your engine combo is very similar to mine so I have high hopes for my first all out assault on the 1/4 mile in a week or two. My Lunati cam is very close to the Bullet that you have and like you I am running 1&3/4 headers. I do have the Northwind intake ported to match the KRE 325 heads. The 8 point roll bar is almost done so I should have some numbers after our next test and tune. Best of luck with your 'new' engine.

[Jim Moshier]

Great job! those are some Stout numbers for 10.5 compression!

[Lee]

Play with the valve lash, if you get a chance.

I had solid roller from Bullet in the 427 SBF I built 12 years ago. It also called for 0.026"/0.026".

I tested on a chassis dyno. Started with the intake lash, and found the motor ran best with 0.021" lash. Then tested the exhaust, it liked 0.024"

Compared to 26/26, the 21/24 gave me 16rwhp at peak, and picked up 25rwhp in the midrange (around 4500rpm).

Your results may vary :-)

[GOAT8U2]

Ignore my ignorance, this was on an engine dyno correct?

I assume this because of the info shared on parts that would make the most sense since..

Dynojet is roughly 11% reduction (then converter slippage)
Mustang roughly 16% (then converter slippage)
Your numbers would be like...
689hp/713tq at the engine if your sheet was taken off a Dynojet.

Killer anyway you slice it.

[leeklm]

Engine dyno is correct

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[GOAT8U2]

Nice

We have a similar combo except your bigger Old Faithful 2.0 cam, interesting, you're at least 30hp more vs my as cast high port and Voodoo cam.

[GOAT8U2]

Double post??

[Lee]

Originally Posted by GOAT8U2

Ignore my ignorance, this was on an engine dyno correct?

I assume this because of the info shared on parts that would make the most sense since..

Dynojet is roughly 11% reduction (then converter slippage)
Mustang roughly 16% (then converter slippage)
Your numbers would be like...
689hp/713tq at the engine if your sheet was taken off a Dynojet.

Killer anyway you slice it.

Your numbers are rougher than you think. I saw a motor dyno at 545 flywheel, then 426 DynoJet, locked converter.

[GOAT8U2]

Ya converter and drivetrain can be easily 16% on Dynojet and my local Mustang Dyno saw a 26% on an auto with slipping converter. Luckily my PTC 10" 0 blade is 3.5% slippage.

Great numbers, I'm doing 2 dyno mod tests to get to a hair over 600hp soon, I'll post back as I think there's 3% hiding in all our combos with these 2 mods rarely no one has.