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Discussion Starter #21 (Edited)
Re: Project "White Lightning" 09 3.7 5 speed

Well, tonight I ran a best of 13.601 @ 100.2mph. SO CLOSE to 13.5s!!!

https://youtu.be/yMtLSB8FNpM
 

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[MTS] Who is this guy?
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Discussion Starter #23

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Discussion Starter #24 (Edited)
Made it out to the dyno today with BJonas. Truck made 236whp and 247wtq! I was a little bummed since I was thinking/hoping it would be around 250 but still not complaining.

Truck is an n/a 3.7 5 speed with full bolt-ons, 3.73 eaton rear, and a Dirty South Tune.

Also ran a best of 13.524 @ 101.2mph

Dyno graph!



Dyno videos!


 

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Discussion Starter #26
@Iarado there was no significant difference between open and closed. The two runs you see I the graph..one is open and one is closed. The truck made 1wtq more with it closed which basically means nothing.

My cut out is before where the stock cat would be. It is about a foot after the header
 

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@Iarado there was no significant difference between open and closed. The two runs you see I the graph..one is open and one is closed. The truck made 1wtq more with it closed which basically means nothing.

My cut out is before where the stock cat would be. It is about a foot after the header

@Skizzo Thanks for that info. Been thinking about a cutout but would like to get something out of it (besides noise). I was reading someplace the best place is behind the last CAT (I have header as well) to get back-pressure ???
 

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Discussion Starter #28 (Edited)
@Iarado I've never believed in the back pressure myth. And as proof that it doesn't make a difference...look at my results. Cut out open and closed have identical curves and statistically insignificant differences in power. I have no cats but I do have the borla muffler and a few feet of pipe after the cut out. Probably about 6ft of exhaust after the cut out.

The only way I see gaining any real performance from a cut out is if you are forced induction and your full exhaust is restrictive at that power level. Cut out could help spool a turbo faster too.

I've actually been thinking of getting rid of my cut out for a while but can't make up my mind. Not due to performance or anything but because of sound really.
 

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Skizzo,
About how much weight you figure you saved by going to the carbon fiber hood?
Inquiring minds want to know.
 

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Discussion Starter #31
@Hhrumph maybe about 5lbs. Not a huge difference.
@Iarado no problem. Happy to share any info I can
 

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Super impressed on your, near, 250 wTQ !
What’s the deal on your Eaton tru-trac??
I imagine your 09 diff is like my 05 (8.06”?).
I ordered mine from the factory 08-2004, with 3.5/5spd/locker
They made me buy traction control and dealer put on a tow hitch. Lol

I like our hi-tech (aluminum) diff and was planning on trying to shove gm 8.5” Carrier in it. Need be. Like corvette that puts 12 bolt gears in the dana 44.
Thanks!
 

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Discussion Starter #33 (Edited)
I don't think you'll be able to get the larger carrier in. My rear is actually out of my old 04 and was swapped from an open diff to the eaton true track gear driven lsd.
 

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Discussion Starter #34
Finally tearing into this thing, so it begins!
 

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Discussion Starter #35 (Edited)
Added my dyno graph to the dyno post!

But here it is anyway:

 

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Our 8” seams to be plenty capable with a nice Truetrac. Summit has that true trac for about 590$. Is that where you purchased?
I love that i5 sound under load!
So, are you saying you’re making near-300bTQ?!!
That’s awesome. Do you have any internal engine upgrades? ( cams, porting, compression ratio)
 

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Discussion Starter #37
Our 8” seams to be plenty capable with a nice Truetrac. Summit has that true trac for about 590$. Is that where you purchased?
I love that i5 sound under load!
So, are you saying you’re making near-300bTQ?!!
That’s awesome. Do you have any internal engine upgrades? ( cams, porting, compression ratio)

@caliheat the rear end is doing well so far, has given me 0 issues. I bought my true trac from drivetrain specialists for like 450 ish. I'm making 247tq at the wheels so that could be like 290ish at the crank assuming 15% drivetrain loss.

I have zero internal mods but if you look another post or two above yours I'm starting work on a ported head which does happen to have a set of cams in it that can be reground...
 

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Good street cams are worth 60+hp on the 4.2 atlas. (215* duration)
Do you know if custom blanks are available for the i5 atlas(‘s)
I was told , some years ago at sema, by comps cams that they could not get more than 15% lift & duration on regrinds. Better than nothing.
Stock duration is 160* ex/ 180* int. Or vis versa lol.
 

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Discussion Starter #39
There was a guy making cam blanks at one point in time but I am quite certain they are no longer made.

The cam specs for the atlas motors are:

Early intake: 160 @ .050" .241" lobe lift .405 valve lift
Late intake: 160 @ .050" .257" lobe lift .434" valve lift
Both exhaust: 168 @ .050" .221" lobe lift .372" valve lift
 
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