Chris Stewart

Thanks everyone. We were hoping for a chance at 8's. I think the power was there, but not enough hook.

Yep and making it home in one piece is always good. It was a private event so the tech was lax.

It seems just as good, these might even spool up better. I'm gonna try getting my dyno run files and overlay an old/new one to compare the curves.

The old school 3bar brick. We can go higher but the power gains were dropping off. Maybe I'll open the exhaust next time.

cmiller8006

I would not doubt if they spool faster. My 6262 I had on the cobalt spooled 500 rpm's faster then a pte 5857. Something about them lol.

Chris Stewart

Here's some dyno runs to compare the old Turbonetics 57/62 at 22psi (blue), vs Precision 62/65 at 20psi (red). Pretty close!

ajrothm

It's weird how it has the same dip up top with both sets of turbos. I guess that's the exhaust back pressuring up or something. I think I'd be putting some cut outs right after the turbos somewhere.. You never know how much power that exhaust could be hurting you.

Pretty good power for 346" and only 20 psi.. Maybe you should have cranked them to 25 psi and shot for 1k on boost only...

Chris Stewart

Very possible, we've done it before. I was thinking that nitrous torque would help for better ET, and back off the boost a little to manage cylinder pressure. We'll have to try the no muffler mod again sometime.

Rkreigh

hey chris,

winter is approaching and hopefully the sale of my house so I'll have some mod money.

I'm debating going smaller displacement and iron block with the afr 225 heads, and an alum intake tapped for direct port alchy

I also have a haltech with flex fuel and 127 lb injectors and champion down pipes.

at the same time, I've got some .82 ar housings not postitive on which turbos I have but I believe they are the 58s

I'd also like to freshen up the manifolds with a good coating, thinking of maybe going black, any recommendations on what's best?

looking to boost it to 1k hp and have it live, that's about as high as I can go with the 4l60 tranny and it will take a lvl 10 build and some luck!

Im also debating using the luntai forged 4.0 stroke, a stock 3.622 or the shorty 4.8 crank. I'm thinking I'd be happiest with the short stroke 4.8 crank and a nice stout wiseco piston

but I'm concerned even the short stroke crank might not be strong enough to survive 800 at the tire (around 1k hp crank)

for the fuel system I want to do a bosche primary and a magnafuel big 7503 or similar pump, and I have the direct port alchy for any trimming up top with the haltech controlling the pump

looking for some haltech help in the va, pa, or east coast ranges

thanks for any advice!

your car has been a inspiration for sure great work!

it won't run out of fuel

Chris Stewart

800rwhp will be easy to hit without pushing too hard. More cubes will take less boost and have more torque off the line, sometimes wish I had about 400ci. We don't use much alky, just a single nozzle with controller on 4, serves mainly as a safety on the street. I do turn up the meth to control IAT's when racing high boost in a hot conditions. I've never coated the manifolds so I'm not sure what works there. They are faded so I might redo them someday.

CamminC5

I'm dropping off my headers and a buddy's turbo exhaust housing at Calico tomorrow for their ceramic coating. Called Jethot for info about their 2500 coating and there's no way I'd spend 700 on coating headers. Calico quoted me 275 for headers and 50 for his housing with 10 day turn around.

Dunn

Great videos, that car is flying! I wish I could nut up and jump on an 4L60 and make it work but Im scared of dumping money into something that may not last 1 pass down the strip

Chris Stewart

$300 sounds pretty fair for the coating. I had to use a fire extinguisher once and it's amazing how well that coating lasted lol.

The 4L60 gets a bad rap. I haven't had any terrible failures from my RPM unit, except losing the 3/4 clutch over and over. Luckily it's not that hard to fix, and with the latest Sonnax drum (Level X type RPM) it's holding good so far to the abuse. Even sprayed thru the shifts on that run. Kinda wondering how it would do with a 2nd gear launch ala Arun style. Might have to try that once.

mdaniel

I'm happy to hear that as I have a zero mile RPM trans sitting in my car now with a new Sonnax drum.

Chris Stewart

Awesome mdaniel, that's a nice trans. I just realized I never posted pics of these beauties.

Turbo-Geist

Looking good, those look just like mine.

Hope you get another chance soon and get on a track with great prep.

TurboCorky

Some very nice numbers, and killer mph

Chris Stewart

First time out driving since the race and notice a knocking sound from the engine. Checked the rockers and springs, they look fine. I'm guessing a rod is knocking, probably pushed it too far with a stock GM crank and hammered the bearings. Looks like time for winter hibernation and start saving for a good 3.622 crank.

4DRUSH

Maybe just the rods, have you ever heard of a stock crank failure?

(although a DragonSlayer crank is badass)

Chris Stewart

Right it didn't fail, but have a feeling it's from crank flex. Oil pressure reads about 10psi below normal. A few years ago we pushed another stock crank build to 1000rwhp, and the bearings were beat up as well. I shoulda known better but was getting away with it until now. I'm thinking dragonslayer too or maybe Lunati signature.

PEETYZ

Great results. Sucks to hear about the motor tho man

CamminC5

That sucks man.... You'll just come back stronger.

Turbo-Geist

Time for a 4.8 shortblock?