INDY 6.1 Heads/Intake Dynoed +40hp - Cherokee SRT8 Forum
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post #1 of 10 (permalink) Old 02-10-2007, 12:05 PM Thread Starter
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INDY 6.1 Heads/Intake Dynoed +40hp

We bolted a set of INDY's CNC ported 6.1 heads and their intake on my SRT-8 this week and then I did some dyno testing today. Numbers were -

375.84hp/379.62ft-lb before this upgrade
407.49hp/396.00ft-lb after the head/intake install

That's about a 32hp improvement at the rear wheels and 40hp at the flywheel. Flywheel hp is up close to 510. Just a little higher than what we'll be seeing from the 6.4 when it's released in these cars in a few years.

The added power is really noticeable from 4000 RPMs to redline. I'm going to try to keep the stock cam in there... for now The ASM supercharger is looking pretty good too. I just don't want to turn this into a "race car". It will see some track action if the weather is good next weekend through.

Tom
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post #2 of 10 (permalink) Old 02-10-2007, 12:16 PM
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Re: INDY 6.1 Heads/Intake Dynoed +40hp

Tbyrne,

I am looking for a good alternative for the gsm Charger. WHat are my options. Also is it wise on these vehicles to change the head under a forced induction situation. I know on some cars this is not the best way to go.


GOOD NUMBERs BTW
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post #3 of 10 (permalink) Old 02-10-2007, 12:22 PM
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Re: INDY 6.1 Heads/Intake Dynoed +40hp

Quote:
Originally Posted by tbyrne
We bolted a set of INDY's CNC ported 6.1 heads and their intake on my SRT-8 this week and then I did some dyno testing today. Numbers were -

375.84hp/379.62ft-lb before this upgrade
407.49hp/396.00ft-lb after the head/intake install

That's about a 32hp improvement at the rear wheels and 40hp at the flywheel. Flywheel hp is up close to 510. Just a little higher than what we'll be seeing from the 6.4 when it's released in these cars in a few years.

The added power is really noticeable from 4000 RPMs to redline. I'm going to try to keep the stock cam in there... for now The ASM supercharger is looking pretty good too. I just don't want to turn this into a "race car". It will see some track action if the weather is good next weekend through.

Tom
You guys go up to New England Dragway at all??
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post #4 of 10 (permalink) Old 02-10-2007, 12:45 PM Thread Starter
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Re: INDY 6.1 Heads/Intake Dynoed +40hp

It's not good to increase the compression ratio when running forced induction. The stock ratio is good and a little lower is better if your planning on running big boost. ASM has a supercharger for the LX cars. They are working on some other things right now but I'm hoping they produce it for the CG SRT-8 too. They upgrade the 8 injectors instead of putting to in front of the intake opening.

I'm heading to Atco next weekend and will be at NED in April.
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post #5 of 10 (permalink) Old 02-10-2007, 03:19 PM
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Re: INDY 6.1 Heads/Intake Dynoed +40hp

Are there anyother mods on this car besides the ported heads and intake? The baseline #'s seem high for a stock RWD car?






Quote:
Originally Posted by tbyrne
We bolted a set of INDY's CNC ported 6.1 heads and their intake on my SRT-8 this week and then I did some dyno testing today. Numbers were -

375.84hp/379.62ft-lb before this upgrade
407.49hp/396.00ft-lb after the head/intake install

That's about a 32hp improvement at the rear wheels and 40hp at the flywheel. Flywheel hp is up close to 510. Just a little higher than what we'll be seeing from the 6.4 when it's released in these cars in a few years.

The added power is really noticeable from 4000 RPMs to redline. I'm going to try to keep the stock cam in there... for now The ASM supercharger is looking pretty good too. I just don't want to turn this into a "race car". It will see some track action if the weather is good next weekend through.

Tom

Jeep SRT-8 A Wolf in Jeeps clothing
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post #6 of 10 (permalink) Old 02-10-2007, 04:42 PM
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Re: INDY 6.1 Heads/Intake Dynoed +40hp

Tom,

Great update on your modification to the heads. Listen on those numbers the stock seem high...do you have an other mods on the vehicle which would help boost those numbers?

Thanks and keep us updated on future runs!!
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post #7 of 10 (permalink) Old 02-10-2007, 05:02 PM Thread Starter
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Re: INDY 6.1 Heads/Intake Dynoed +40hp

Sorry, I missed the other mods. It has Kooks long tube headers with cats, the rest of the exhaust is stock. K+N induction and a B&G Stage II tune.
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post #8 of 10 (permalink) Old 02-11-2007, 03:56 AM
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Re: INDY 6.1 Heads/Intake Dynoed +40hp

Quote:
Originally Posted by tbyrne
Sorry, I missed the other mods. It has Kooks long tube headers with cats, the rest of the exhaust is stock. K+N induction and a B&G Stage II tune.
What make of dyno did you use? I used a 4 wheel drive type dyno (w/4 rollers)...not a dyno jet w/2 and posted 373 hp. Those # sound right.
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post #9 of 10 (permalink) Old 02-11-2007, 07:41 AM
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Re: INDY 6.1 Heads/Intake Dynoed +40hp

decent increase.. Can't wait for the ASM supercharger or a turbo kit!
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post #10 of 10 (permalink) Old 02-12-2007, 09:48 AM Thread Starter
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Re: INDY 6.1 Heads/Intake Dynoed +40hp

The car was tested on a DynoJet.
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