[solar68]

I took the GTO into Harry’s (HK Motorsports dyno tuning) in Van Nuys Ca for a full tuning session, i had felt it wasn’t pulling as hard as it could, and the only way to find out was to send it to a pro. Harry is an old school pontiac tuner, races and builds them all.

I had the new Holley Ultra Double pumper installed, they started by dialing in the carb as good as possible then did a small pull. They welded in bungs to test A/F ratio and started pulling data.

They had to change the plugs to a cooler plug, reject the carb and tune the air bleeds

The big part was the recurving of the distributor, the MSD plug and play was way off and not giving anything close to full timing- I don’t have all the numbers, but its pulling now on the chassis dyno, what the motor pulled on an engine dyno, pulling 415+ ftlbs at the wheels.

Super happy so far and cant wait to drive this thing once tuned

 

[ylwgto]

Badass! Nothing like hard data to dial things in

 

[billy.king]

What motor and mods are you running?

 

[geeteeohguy]

415 TQ at the rear wheels when the original engine was 430-440 at the crank is very, very impressive. Is this a 455 or a 400?

 

[solar68]

I’m running a 400 based 461 with the following:

• ram air style heads
• speedmaster aluminum intake
• Holley “ultra” double pumper 750 flowed built and set up by HK Motorsports
• Isky cam
• 1.6 roller rockers
• Doug’s 1 7/8th’ headers
• MSD dist
• TKX 5 speed

It’s pretty stout, but didnt have the “ooomfh” that i thoughts it should have

Thsi tuning has made a world of difference, the data to real understand each change and “safely” set the motor up

 

[RMTZ67]

Do you know what the numbers were at the start?

 

[solar68]

Do you know what the numbers were at the start?

The motor alone made 432hp/500tq on a engine dyno- the tune really brought it out-

 

[solar68]

Here are the numbers at the wheels on a chassis dyno, take the drivetrain loss into account @20-25% and this is making power!

Very happy now

 

[Baaad65]

I would love to have it tuned and dynoed, the Butler dyno on mine shows 472hp 526tq with the stock intake port matched and a Cliff Ruggles qjet but I swapped in an Eddie performer rpm, 850 Quickfuel dp w/ a 1/2" phelonic spacer and Scorpion 1.65 race rockers so I'm curious to see what if any I gained. I did curve the dizzy different than most and I know this I can't get the drag radials to hook so it must have something good going on 👍

 

[solar68]

I would love to have it tuned and dynoed, the Butler dyno on mine shows 472hp 526tq with the stock intake port matched and a Cliff Ruggles qjet but I swapped in an Eddie performer rpm, 850 Quickfuel dp w/ a 1/2" phelonic spacer and Scorpion 1.65 race rockers so I'm curious to see what if any I gained. I did curve the dizzy different than most and I know this I can't get the drag radials to hook so it must have something good going on 👍

I have been wanting to do this, and i suggest anyone who can afford that should do it!

FYI- i have a stage 2 SMI qjet if anyone needs one for a sweet deal- only 500 miles on it!

 

[Jared]

Nice flat torque curve. Like Baaad, I'd love to get mine done too but really lack the motivation to search out a shop to do it.

Up until a few weeks ago I was still running the carb I had on mine that I used for the break in time. It was a 600 CFM Edelbrock Performer that I knew it was way undersized and was robbing some power. I was using it because I knew it ran good on the tired 400 that came out of the car and I didn't want to add "questionable carb" to the mix. I upped it to a 800 CFM Eddy Performer, did a couple minor tweaks, and the results were night and day. It still needs to be dialed in but I have it pretty close. 1st gear has basically become useless. My engine is built for mid to upper mid range power and it'll break the tires loose in third gear at 30 mph now. Added bonus is fuel consumption improved with the larger carb. It's still bad, but 7 - 9 mpg looks way better than the 4 - 5 it was getting before.

 

[Jared]

BTW Glad you're having better luck with the second engine. Still sucks what happened the first go around.

 

[lust4speed]

• ram air style heads
• speedmaster aluminum intake
• Holley “ultra” double pumper 750 flowed built and set up by HK Motorsports
• Isky cam
• 1.6 roller rockers
• Doug’s 1 7/8th’ headers
• MSD dist
• TKX 5 speed

Can we have some more information on the "ram air style heads"? Also cam specs?

Harry K takes his time wringing out the last little increases on the dyno. Wish he were closer to us.

 

[solar68]

Can we have some more information on the "ram air style heads"? Also cam specs?

Harry K takes his time wringing out the last little increases on the dyno. Wish he were closer to us.

Running Edelbrock 72cc round ports! And an Isky cam with 485 lift and 108 lobe sep

 

[solar68]

Well the car makes power,

But i picked it up today, and on the drive home something is wrong with the clutch, its slipping bad.

It’s likely one of 2 things, something got into the clutch or the throwout bearing doesn’t have enough air gap- it dyno’d fine, but started slipping ont he drive back home (even in 5th)!

I cant get a break! Mcleaod is 2 blocks from my office, so i got a fresh kit from them.

The clutch i have in it is American powertrains 650hp kit- it obviously worked on the dyno, and there is only 900 miles on the motor/trans…….. something either settled in (air gap on the bearing) or a burned clutch…

 

[Jared]

Which McLeod clutch did you go with? I'm running their Street Extreme clutch in mine and have been happy so far. It engages smooth and the pedal isn't as heavy as I thought it would be (I'm running the stock style mechanical clutch, I'm assuming yours is hydraulic?). Only thing that is slightly odd with it is it makes a whirring sound when partially engaged. It's the only ceramic clutch I've ever run and a assume it's due to the composition but it is odd.

 

[lust4speed]

Bummer about the clutch. Pontiac Outlaw Racers from Arizona are coming out to California tomorrow (Saturday 6-18-22) and racing at Barona. Several of us from Inland Empire GTO Club will be attending the evening event that runs from 4:00 to 10:00 PM. I'm leaving the GTO at home and taking the '65 Cat Safari wagon out for its maiden voyage down the track. It's not an inclusive Pontiac event and the track will also be running test-and-tune and AFX cars from what I understand.

 

[PontiacJim]

Which McLeod clutch did you go with? I'm running their Street Extreme clutch in mine and have been happy so far. It engages smooth and the pedal isn't as heavy as I thought it would be (I'm running the stock style mechanical clutch, I'm assuming yours is hydraulic?). Only thing that is slightly odd with it is it makes a whirring sound when partially engaged. It's the only ceramic clutch I've ever run and a assume it's due to the composition but it is odd.

Hmmm. I ran a ceramic clutch disc and thought the same thing because I never used a ceramic disc.

See the "shiny" on the clutch disc springs? That's what happens when you use the Hays flywheel and the taller headed crank bolts - they hit the springs when you are slipping out the clutch to take off because they sit too high. Gotta use the correct "thin" headed crank bolts.

Don't know if this applies to you, just pointing it out when you stated the whirring noise when slipping the clutch disc - my experience also thinking it was the ceramic disc material sound.

 

[Baaad65]

I'm curious did the dyno shop notice this? And have you questioned the shop, usually when your car goes into a shop doing fine and comes out broken there should be questions for the shop right?

 

[solar68]

I'm curious did the dyno shop notice this? And have you questioned the shop, usually when your car goes into a shop doing fine and comes out broken there should be questions for the shop right?

I called him as soon as I got home and he said he didnt notice, he said that it wouldn’t have pulled hard on the dyno slipping (he is right)- the hydro throw out may not have enough airgap- but i am ready to replace it all..

The shop had me sign a release if anything went, so they are clear…..

I’m happy with tuning the clutch thing just sucks….