408 LT1 build

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04-02-2008, 01:47 PM

#76

FASTFATBOY

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Quote:

Originally Posted by TitoPR221

30 lb/hr injectors are good to at least 505 hp at 85% duty cycle. If the 408 will be turning 6,200 rpm ± 100 rpm, then it'll be making about 489-505 hp normally aspirated.

More math I see, you forgot to factor VE, BSFC, BMEP into this equation.

You put 30lb injectors on that 408 and it will run out of injector, I have seen 355 inch motors almost max out 30lb injectors. At or below 7000 rpm.

Unless the 408 is HORRIBLY built with junk heads, the wrong cam and tuned wrong. It needs 42lb injectors.

David

04-11-2008, 05:51 PM

#77

Formula408

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http://www.mofbody.com/blkchevyz/408lt1idle.wmv
Here is a link to a cheesy little video I made of the 408. Please Ignore the messy garage and the Crappy exhaust (its temporary).
BTW: Its gonna pull waaaay beyond 6200 I have rev limiter set at 6300 now and it definatly wants more.
I'll keep you guys posted about how injectors do and other odds and ends. hopefully I can dyno soon!

04-11-2008, 05:56 PM

#78

mdacton

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I tried a 30# injector...it did fine on the street. When she dead hooked at the track and pulled the wheels it hit the ground quick. Injectors were done@ about 4500-5000 with a load on the car.

I tried again and tried to run them 125%

didn't work.

You will need 50 or more. I went with a 60....still waiting on those

04-11-2008, 06:05 PM

#79

Stl94LT1

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The car sounds pretty good!! Where are you at in MO?

04-11-2008, 06:12 PM

#80

Formula408

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Quote:

The car sounds pretty good!! Where are you at in MO?

Warrenton about 30 miles west of you.

04-11-2008, 06:16 PM

#81

Stl94LT1

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Cool, I'll be looking out for you!!

04-11-2008, 06:17 PM

#82

mdacton

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Quote:

Originally Posted by Stl94LT1

Cool, I'll be looking out for you!!

why? dinner and a movie?

04-11-2008, 06:21 PM

#83

Stl94LT1

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Quote:

Originally Posted by mdacton

why? dinner and a movie?

Nah, just want to run him in my Cobalt.

04-11-2008, 07:13 PM

#84

Pyrodawg

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what kinda of FP gauge is that?

04-11-2008, 07:19 PM

#85

Formula408

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Quote:

what kinda of FP gauge is that?

Please dont ridicule me

Its a Glow Shift but its decent for the 30 bucks or whatever I paid for it. As long as it works and reads good...

04-12-2008, 02:05 AM

#86

marshall93z

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Quote:

Originally Posted by FASTFATBOY

I have seen a 396 LT1 make 740 hp naturally aspirated and not turn past 7500 rpm. How do you explain that?

David

I'll explain it.... SB2 heads!

04-13-2008, 01:29 AM

#87

Pyrodawg

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Quote:

Originally Posted by Formula408

Please dont ridicule me

Its a Glow Shift but its decent for the 30 bucks or whatever I paid for it. As long as it works and reads good...

ive actually looked at those before and they look awesome IMO... no ridicule at all.. i was interested in them but didnt know how accurate they are... have u verified its accuracy with a mechanical FP gauge?