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408 Nitrous guys come on it

27K views 32 replies 11 participants last post by  SRTthis798 
#1 · (Edited)
408 Nitrous guys come on in

Anybody out there with a 408 combo and a little juice? I'm working on one now 11.5:1, roush 200 heads 830 HP 4150 carb cold fusion fogger c4 & 3.73's Just wanted to get some ideas what you other guys were running with similar combos. I know the heads are gonna hurt me but they were on the project when I bought it so I'm gonna see how they do and then decide if I'm gonna change them out.

So post up a little about your combo, your times and how big a shot you are running.

Thanks
 
#3 ·
Great numbers! I have a solid roller .609 lift. I'm really afraid my heads are gonna put my motor numbers in the 400's and they really should be in the 5's. I thought about ditching the 200's for some afr's but the large valves may not clear without having to tear the motor apart and notch the pistons.
 
#5 ·
Well, I'm sure I have enough carb then if it's working for you. lol
you get any motor runs on it before having it back apart?
 
#7 ·
ok, keep me posted. Mine won't be done for a couple months, maybe more. Time and Money, I never have enough of either!
 
#9 ·
i run a 410 stock block with tfs highports,solid cam,pro sys carb,super vic..im in tuning and testing stages still but its run a 10.61@129 n/a and on only a 150 shot its been 9.76@142 tuning and me just driving it harder im certain it will drop 1-2 tenths and then with the 250 shot should net me close to the 9.20's and im sitting right at 10.8.1
 
#10 ·
very nice! That's close to where I want to be on motor. I'm shooting for lower than 10.50's. My last motor ran 10.50's @ 10.0:1 with vic jr heads on a 393 stock block under .600 lift flat tappet cam. Not sure how bad the heads are gonna hurt me though. I'm hoping the compression (11.5:1) will make up some of what the heads are losing. How big a cam are you running? What size is the carb?
 
#11 ·
408W here, stock block Eagle guts with 10.2:1 compression. AFR 205's , FTI solid roller and a had both a C4 and 'glide behind it.

When I had the 4.10's and C4 with the loose 8" converter the car ran 10.30's @ 131 at 3250lbs. Put on the nitrous and 3.73's broke the converter and eventually the C4 running 9.70's on a 100 shot.

Swapped to a 'glide, slowed the car down a bit N/A running 10.50-10.60 at 128-129 but on the bottle it's gone 9.40's @ 143 blowing through the converter on a 200 shot. It's gone bottom 9.50's @ 141 on a safe 150 shot tune up. Recently gone into the 9.80's @ 137 on a 50 shot but I did go to a 4.30 gear and a 29.5" drag radial with a tightened up converter. I haven't run it since but would love to see what it'd do not overpowering the converter but......


....after 6 years of abuse I broke the stock block. Haven't got it torn down yet but the right front corner is busted and the oil pressure is down so I'm pretty certain it's into the main area.
 
#12 ·
That's the kind of numbers I'm shooting for. I'd like to get down to 10.20-10.30 on motor and then turn on the fogger and enjoy the ride into the single digits. Can't really complain about the block letting go after 6 years running those numbers, I'd say that you got your money's worth. Some of my father in law's buddies have been trying to convince me to go powerglide and swear that I will run faster but I see that it slowed you down. You have to notch your pistons for those AFR valves? Couldn't remember if the 205 had the same huge valve as the 225.
 
#20 · (Edited)
Can't really complain about the block letting go after 6 years running those numbers, I'd say that you got your money's worth. Some of my father in law's buddies have been trying to convince me to go powerglide and swear that I will run faster but I see that it slowed you down. You have to notch your pistons for those AFR valves? Couldn't remember if the 205 had the same huge valve as the 225.
Nope, I'm not too upset about busting up the block, it was the eventual goal so that's been achieved. I have a solid 1972 351W short block going in to finish up the year and then I'll likely use that stronger earlier block to rebuild the 408 if I can't swing a Dart/FRPP block. I pulled it today, I broke it good. Split #1 main cap, broke from cap mounting surface to the #1 main and out to the edge of the block. I pulled a huge chunk of cast iron out by hand after pulling 1 main stud. It's junk LOL!

Honestly I've had both the C4 and 'glide. For durability and on the bottle performance the 2 speed kills the C4. Sure the converter is tighter and it doesn't have the N/A ET anymore but on the spray the C4 can't touch it. 3 years on the 'glide now and it's been flawless. C4 had to be gone though a couple times and I ended up shattering a hardened input shaft and screwing up a $900 converter. It sits broken in the garage, 3 speeds have their place but a big inch stroker on spray, I'd never go back to one. The 'glide just gets it done well.

The AFR 205's have a big 2.08" valve in it. I never had to cut addition clearance in the pistons, my SRP's had plenty of valve relief in them with more then enough room to spare even with a .688" lift cam.
 
#13 ·
A buddy of mine had one with 225s, victor intake, biggest doug herbert solid roller nitrous cam, a glide with a b&m nitrous holeshot converter. It went 5.50s in the 1/8 on 400.
 
#15 ·
I would kill to run that number! I'm pretty sure my motor could handle that shot but lenny said the converter should only be hit with a 300 shot so that's probably the highest I'll go.
 
#19 ·
i figured id squeeze in here as im looking for info too... heres my build

69 block studded girdled half filled
vic jr cnc
super victor351
solid roller 680+/680+
nx gemini twin-edel plate 2 stage
glide 5500 nitrous conv.
31.-10.5-15
13:8:1
pro systems 950hp carb

street race car, looking to go high 9s on motor 150shot first kit 250 second.. what do u think
 
#22 ·
Nice number. What compression is that motor? I was surprised to see your only running a 26 inch tire with that gear/motor/nitrous combo, any problems hookin?
 
#27 ·
went 10.50 and 9.50 tonight..still on the same tuneup ...this thing bottom 9.0's in it with the big shot....makes me never want to go back to a turbo

funny u say that man i was ALL TURBO until i took a ride in a high comp nitrous street car. lol its changed my life. i havent thought about a turbo since i had my twin sn95....

duffman/jimmy8541> haha yeah well here in daytona street racing is life and either u have a high comp nitrous car or its a pump gas turbo car. not much s/c's tho. we have 100 octane and 104 here so for us thats considered pump gas lmao! shoot 13:8:1 is kinda low here. alot of the guys i race with run 14:1 or 15:1 chevy stroked small blocks on the street..i mean not pull off the trailer and race. i mean drive 15 or so miles just to hang out then go race then drive it home.were really big into consistancy and tuning so we cant afford to foul plugs n traffic and all that other b.s.
 
#29 ·
lovin the numbers I'm hearing guys, I'm just itching to hurry up and get mine done. Think I'll get it running just to see how it does and then ditch the iron 64cc heads for some 58cc's or so and try and bump the compression a little more.

TC, thanks for the tranny swap info. My father in law's race buddy builds glides so I'm sure he has one around for me.

SN95, think you're the first person I've heard say high compression nitrous car over turbo car hands down. I have always wanted to go turbo, but hearing you say that makes me even more excited to get this car done. The will really be my first real nitrous car.
 
#30 ·
hey man me too!!! im like RINGS Belt drive pushrods away from being done!!!! my good freind mike (oinkaodeoink) specializes in turbo cars as he helped me do mine and ive helped him do MANY different kits and i just cant get away from the bottle. its actually amazing how a 11:5:1 HEAVY G body on spray feels way more powerful than an 03 cobra or a procharged 302.. not to meantion the wieght and MONEY u save going spray? i dunno i guess i just had a change of heart lol
 
#32 ·
I know its a really old post but, my stock block 408 been taking some abuse this year started with 200 shot then just upped it to a 300 shot on a induction solutions fogger and running 24 degrees timing and hitting wheelie on the street and tearing up the street game right now in norcal taking it to the track in 2 weeks to see if i can get a mid 8 second pass with this motor while my dart block gets fixed burnt 2 pistons on a 375 shot whats the most anyone sprayed on a stock block 351 without braking
 
#33 ·
ive spoken with a few guys north of 500 on a stock block... but they also dont make a ton of power NA.

my motor might end up with some where near a .022 jet but thats going to be about it. i'll make a lot of power NA so i cant spray a ton on a stock block with out worrying about putting the crank into the oil pan
 
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