mrr23

iTrader: (3)

finally got around to it today. was done at norris motorsports.

review of setup
408
11.5:1 compression
SLP lid
vinci ported MAF ends
NX 85mm TB
NX intake
ASP under drive pulley
42# SVO injectors
2.02/1.60 ported 4.8L heads
232/240 .551/.551 (1.7 ratio) 117 LSA
crane 1.8 shaft rockers (brings lift to .589/.589)
dynatech 1 3/4 stepped 1 7/8 headers w/3" collectors
bassani tru-duals 2.5" w/x-pipe
yank py3400 converter
3.73 gears
275/50-15 nitto DRs
250 NX NXL DP nitrous

this run was on motor converter unlocked



this run was on motor, converter locked 21* timing



same run with 26* timing



this run is with the 250 shot. tires spun on the dyno and didn't hook until almost 5500 rpms



here's the same run using mph, so you can get a little better view of the run

beardWS6

iTrader: (1)

Nice power on the spray. I`m spraying a 200 shot on my 408 also!! Love It!

DeltaT

iTrader: (5)

Very solid numbers. That thing must scoot!

Jim

1bigcam

iTrader: (9)

what kind of trans??

mrr23

iTrader: (3)

4L60E

Shoulder Shaker

iTrader: (36)

How many passes have you made on the tranny with the spay? Those are some stout numbers. Congrats.

pdd

iTrader: (3)

wow-that must be sick when the nitrous hits

01SOMm6

iTrader: (4)

^^it Is^^

mrr23

iTrader: (3)

since i've owned the car? around 60+ at the track and i lost count on the street.

ExceSSive

iTrader: (13)

Nice...what does it run? It must pull like a MF when you flash the verter.

red fury

iTrader: (1)

so you are running a 408 with ported 4.8ltr heads..... do you have some crazy aggressive port job on them or is it just over hyped that 4.8/5.3ltr heads are just to small for anything over 383ci???

mrr23

iTrader: (3)

when i went to the track, i was on a 180 shot.

here's the timeslips

motor was 11.84 @ 117 nitrous was 11.189 @ 128.24

it sounds slow by looking at those numbers

if you look at the best NA vs nitrous run, you'll see the 330' mark was only .1 lower and the 60ft was about the same. traction limiting, i didn't hit the nitrous until almost 200' out. so, there's plenty more in it. it's a solid low/mid 10 second car back then. now, with the 250, who knows? the car is a full weight, nothing removed, full on drive it everday car.

i'm a little disappointed with the NA numbers. but hey, how many 650+ rwhp daily driven cars are there?

mrr23

iTrader: (3)

yes, they are ported 4.8L heads. here's the webpage i made while building the motor www.stealthram.com/408.htm the head flow specs are here: http://www.stealthram.com/familypics...48headflow.gif

the exhaust side is on the low side versus most other heads. i'm in the air about how much they are restricting the motor because of the exhaust port. these heads used to be on the wife's car. so, i used them instead of buying AFR heads. something i'm looking into for next year.

Jpr5690

iTrader: (13)

Wow Even The "ultra Efficent" Midsized Yank Converter Lost 25 Hp When Unlocked

I Can Even Dream What My Pos Midwest 4000 Looses Unlocked.. All Well I Did 430 Unlocked On My 346

mrr23

iTrader: (3)

yep, my motor sucks, compared to most 346 motors.

Jpr5690

iTrader: (13)

Didnt Say That .. Just Stating My Thoughts.. You Drew Your Own Conclusion

edcmat-l1

iTrader: (10)

Nice nitrous numbers. Where'd you come up with the cam numbers? Is it .551 with the 1.8s? Why so wide on the LSA?

ExceSSive

iTrader: (13)

For your mods I think you make good power. I think your cam is a bit on the mild side for a 408 and some AFR heads would benefit you in my opinion. Autos are not dyno monsters...but they are great at the track with a nice stall.

Your compression is just right for a bigger cam...244/248 or something like that ( I am no expert), your exhaust set up looks awesome...(I should have true duals). What is it like with that converter and those gears ? It seems like 1st gear would be useless due to tire spin...you get decent traction?

Keep the updates coming.

Frost

iTrader: (45)

If you get some more dyno time you could probably find a bit more tq with some more work on the AFR (unless you have it like that to help on the bottle already...)

smok'nZ

iTrader: (160)

how does that intake compare to an ls6