N20

[dragrazor]

Checking for advice on N20 timing retard on 572 with multiport and 14:1 comp ? any one have a similar set up ? my last BB liked about 6 degrees less using a fogger o

n carbureted, thanks to those replying

 

[6PKRTSE]

Every engine, every tune is different. You just have to adjust accordingly, read the plugs and keep watching e.t. and MPH until it falls off one way or another. Obviously, 2 O2's and 8 EGT'S will help as well.

 

[dragrazor]

Thanks for the reply, fully realize will take more exact actions to get the best tune possibly, was just asking for an approximate, thanks for your time

 

[RemCharger]

Every engine is different , the old 2° per 50horse or whatever is not a good rule to go by. My 383 was at 42 and I asked Monte S , he said drop it to 28.( approx 250 shot).
Start at 24-26 and work your way up would be my best guess, but just a guess

 

[dragrazor]

thanks for the guess, is all I was looking for

 

[WS23U1]

How much shot are you giving it and what fuel are you using?

 

[Hemirunner]

Checking for advice on N20 timing retard on 572 with multiport and 14:1 comp ? any one have a similar set up ? my last BB liked about 6 degrees less using a fogger oView attachment 1400897n carbureted, thanks to those replying

Nice setup. Who built the intake?

 

[dragrazor]

Nice setup. Who built the intake?

Hogan, thanks

How much shot are you giving it and what fuel are you using?

Renegade pro e-85, starting with 100 and slowly working up. Wont spray till engine is tuned as good as can be W/O it..........

 

[Budnicks]

a progressive tuner is better,
I'd look on line for a good one
I don't have any good recommendations,
as to who's is any good now

take a lil' timing out at a time, as it goes down the track
manage the bottle pressure too, run it at a constant like 900psi
highs & lows will mess with the hp & the accuracy' or effeciancy of the tune
to be repeatable
don't/won't kill so much power down low,
running like 20*-24*s of timing because you're runing 300 shot of N2O
taking all 12* out at the hit, does work but not as well
as the more N2O is added

(I've been out of it for a while now, used to run it quite a bit,
I ran 3 kits a 150-300hp (depending on track prep) plate kit under the carbs used at the launch,
release of the transbrake button
a 300-500hp spraybar kit plumbed & epoxied inside the manifold, much like a plate kit but more flow
& closer to the tops of the runners
& a 350-500hp port kit (generic named Fogger an NOS co. term)
down on the bottom of the intake aimed at the centerline of the intake valve

most 'full passes on fully prepped tracks' take out about 2-3* of timing going down track
for every 100-150hp of N2O added, thru a progressive timer
some 3 full N2O kits
ranging from 800hp total to 1300hp total, when I used all 3
some places I could only use 1 or 2 maybe
I never lifted an intake top or had a failure, backfire because of N2O tune
by the time I got down track, I started out at like 34*-36* total,
I was at like 12*-16*s total crossing the stripe 1320 or 660 on 1/8th mile

It worked well for what we had back then
ran best of 6.69 @ 217 1/4 mile, Sears Point IIRC a mild 526cid T/S combo
back in early 2000's , run in the 4.20's in 1/8 mile like 178-185mph-ish

talk to an expert that's up on it, "the current technology"
don't build/tune by committee
the technology is constantly changing

make sure to run a dedicated pump/s & bypass/s style regulator (multiple if neccessary),
adiquate for your HP & needs for the N2O,
seperate from the fuel system, that you run for the engine EFI or carbs

I'd also look into & running really good quality solinoids,
don't be cheap/not there
(I used Powerdyne not sure they are even still in business, best closed pressures
& best seats to stay closed at the time I was using them)
if one hangs open (or closed) it can be dramitic (especially open)
& very expensive to say the least,

It's also mandatory to have good battery power 'constantly' too
fluxuations in any of them can be really BAD

good luck

 

[33 IMP]

Engine masters blew up a 305 Chevy with a 300 shot. Monte Smith said it should have been fine with that shot IF they had taken enough timing out. Ever since I have decided to be very conservative, pulling out more timing than recommended.
I like Remchargers suggestion.

 

[dragrazor]

a progressive tuner is better,
I'd look on line for a good one
I don't have any good recommendations,
as to who's is any good now

take a lil' timing out at a time, as it goes down the track
manage the bottle pressure too, run it at a constant like 900psi
highs & lows will mess with the hp & the accuracy' or effeciancy of the tune
to be repeatable
don't/won't kill so much power down low,
running like 20*-24*s of timing because you're runing 300 shot of N2O
taking all 12* out at the hit, does work but not as well
as the more N2O is added

(I've been out of it for a while now, used to run it quite a bit,
I ran 3 kits a 150-300hp (depending on track prep) plate kit under the carbs used at the launch,
release of the transbrake button
a 300-500hp spraybar kit plumbed & epoxied inside the manifold, much like a plate kit but more flow
& closer to the tops of the runners
& a 350-500hp port kit (generic named Fogger an NOS co. term)
down on the bottom of the intake aimed at the centerline of the intake valve

most 'full passes on fully prepped tracks' take out about 2-3* of timing going down track
for every 100-150hp of N2O added, thru a progressive timer
some 3 full N2O kits
ranging from 800hp total to 1300hp total, when I used all 3
some places I could only use 1 or 2 maybe
I never lifted an intake top or had a failure, backfire because of N2O tune
by the time I got down track, I started out at like 34*-36* total,
I was at like 12*-16*s total crossing the stripe 1320 or 660 on 1/8th mile

It worked well for what we had back then
ran best of 6.69 @ 217 1/4 mile, Sears Point IIRC a mild 526cid T/S combo
back in early 2000's , run in the 4.20's in 1/8 mile like 178-185mph-ish

talk to an expert that's up on it, "the current technology"
don't build/tune by committee
the technology is constantly changing

make sure to run a dedicated pump/s & bypass/s style regulator (multiple if neccessary),
adiquate for your HP & needs for the N2O,
seperate from the fuel system, that you run for the engine EFI or carbs

I'd also look into & running really good quality solinoids,
don't be cheap/not there
(I used Powerdyne not sure they are even still in business, best closed pressures
& best seats to stay closed at the time I was using them)
if one hangs open (or closed) it can be dramitic (especially open)
& very expensive to say the least,

It's also mandatory to have good battery power 'constantly' too
fluxuations in any of them can be really BAD

good luck

View attachment 1404703

Thanks so much for a very thorough and informed reply, unsure my FAST 303000 will have that capability to adjust in increments. We are not beginners with nitrous. But was back in mid 90s and using NOS fogger plumbed directly into BBC intake with a dominator. Took many passes to get it o run flawlessly from launch thru traps. Here it is 25yrs+ later, so checking to see the latest improvements etc. We do have an additional fuel pump for nitrous engagement as we did back then, so hopefully set up for sure in that area. Bought a kit vs assembling one from various retailers. Will look at Top Gun on line later this morning, AGAIN thanks for the time it took you and the information you shared

 

[Budnicks]

Thanks so much for a very thorough and informed reply, unsure my FAST 303000 will have that capability to adjust in increments. We are not beginners with nitrous. But was back in mid 90s and using NOS fogger plumbed directly into BBC intake with a dominator. Took many passes to get it o run flawlessly from launch thru traps. Here it is 25yrs+ later, so checking to see the latest improvements etc. We do have an additional fuel pump for nitrous engagement as we did back then, so hopefully set up for sure in that area. Bought a kit vs assembling one from various retailers. Will look at Top Gun on line later this morning, AGAIN thanks for the time it took you and the information you shared

You're more than welcomed, hope it helps some
Top Gun N2O systems, I don't even know if they are still in business...

I used Jacobs electronics controller, way back when, for the timing controller
with a series of control nobs & plug-in chips (like the MSD chips)
old technology
&
some home brewed deal, for the N2O, progressively increasing
an electronics guy/good buddy of mine Rob came up with,
wired in thru 3 separate 30amp Bosche relays (1 each kit/pair of soleinoids)
to protect from, voltage drops & spikes
& worked to soften the hit from each added kit 'coming in'
over 'like' a 1/2 a second, each, at specific spots down the track
with 3 separate bottles

(timed like example;
#1 starting line at launch to open at release of the transbrake or linelock,
then open #2, at 2.5 sec.s into the run, open #3, at 4.5 sec.s
shut off when the throttle is off
thru a micro switch on the linkage, or manual toggle if an emergency, as override
all times/delays, were depending on track conditions, what kit (?) was used where)

a 'rheostat of sorts' by the opening valve/solenoids let more pass thru
(if any of that makes any sense)
N2O it was wired in thru a progressive MSD system, GRID IIRC
(I don't think the system was designed for it, way we used it, but Rob made it work)

Rob's gone now so I have no way to go back & ask, he was a genius

 

[Nxcoupe]

Thanks so much for a very thorough and informed reply, unsure my FAST 303000 will have that capability to adjust in increments. We are not beginners with nitrous. But was back in mid 90s and using NOS fogger plumbed directly into BBC intake with a dominator. Took many passes to get it o run flawlessly from launch thru traps. Here it is 25yrs+ later, so checking to see the latest improvements etc. We do have an additional fuel pump for nitrous engagement as we did back then, so hopefully set up for sure in that area. Bought a kit vs assembling one from various retailers. Will look at Top Gun on line later this morning, AGAIN thanks for the time it took you and the information you shared

I always go 2 deg per 50, then take another 4 or 5 out on top of that and read plugs. I went through about 20 pistons learning the hard way til I got it all figured out. My situation was unique due to class rules.
I would pull hardly anything out in first gear because engine load was low, then pull more each gear til I hit 4th, then I'd pull the total amount. 4th is when I used to melt pistons.
I'd say if your all motor total is 38, start at 24 or 26 with a 250 and see how the plugs look. If it was my car, knowing what I know, I'd start with the smallest jetting, 100 or so, and pull 8 or so degrees, check your distribution and read the plugs, see how tge engine likes it. Go in baby steps. Good luck. Nitrous is like a hot chick with an std, you know you want to hit it, but you're afraid to. Lol

 

[dragrazor]

I always go 2 deg per 50, then take another 4 or 5 out on top of that and read plugs. I went through about 20 pistons learning the hard way til I got it all figured out. My situation was unique due to class rules.
I would pull hardly anything out in first gear because engine load was low, then pull more each gear til I hit 4th, then I'd pull the total amount. 4th is when I used to melt pistons.
I'd say if your all motor total is 38, start at 24 or 26 with a 250 and see how the plugs look. If it was my car, knowing what I know, I'd start with the smallest jetting, 100 or so, and pull 8 or so degrees, check your distribution and read the plugs, see how tge engine likes it. Go in baby steps. Good luck. Nitrous is like a hot chick with an std, you know you want to hit it, but you're afraid to. Lol

thinks for the numbers to try, going with 100 shot in beginning, look things over and move up some slowly. Was going to be even a little more on retarding, was thinking about 3 then 6 or 7......Is not a drag car, just a serious street machine(hope it is serious) Thanks again

 

[6PKRTSE]

I have mine on a progressive controller and also use an MSD grid with a 350ish on the first stage and another 400ish on the second stage. Also run a Racepak driveshaft speed sensor for traction control.

 

[Nxcoupe]

thinks for the numbers to try, going with 100 shot in beginning, look things over and move up some slowly. Was going to be even a little more on retarding, was thinking about 3 then 6 or 7......Is not a drag car, just a serious street machine(hope it is serious) Thanks again

I would go 6 or 7 on 100 and play it safe. Don't go too rich either. That was something Monte Smith determined was to pull timing and not add fuel. He was running in the upper 12s to 1 af ratio but pulling more timing to compensate. He said it made more power if all the fuel was consumed and a leaner mixture burned faster so less timing was needed. We are experimenting on a friends car and so far the theory is holding up in practice. He was a brilliant man, and quite a loss for motorsports when he passed.

 

[HEMI-ITIS]

Every engine is different , the old 2° per 50horse or whatever is not a good rule to go by. My 383 was at 42 and I asked Monte S , he said drop it to 28.( approx 250 shot).
Start at 24-26 and work your way up would be my best guess, but just a guess

RIP Monte Smith!! He was a legend.

 

[dragrazor]

I would go 6 or 7 on 100 and play it safe. Don't go too rich either. That was something Monte Smith determined was to pull timing and not add fuel. He was running in the upper 12s to 1 af ratio but pulling more timing to compensate. He said it made more power if all the fuel was consumed and a leaner mixture burned faster so less timing was needed. We are experimenting on a friends car and so far the theory is holding up in practice. He was a brilliant man, and quite a loss for motorsports when he passed.

thanks now my search for plugs,

 

[Nxcoupe]

thanks now my search for plugs,

If you are running ethanol(E85), plug coldness isn't as big of a deal. I use recess tip plugs that have a side gapped ground strap. You can run a hotter plug than with gas.

 

[dragrazor]

If you are running ethanol(E85), plug coldness isn't as big of a deal. I use recess tip plugs that have a side gapped ground strap. You can run a hotter plug than with gas.

have seen that a few times researching

If you are running ethanol(E85), plug coldness isn't as big of a deal. I use recess tip plugs that have a side gapped ground strap. You can run a hotter plug than with gas.

finally found the NGK site that had a several hundred page catalog that broke it down by dimensions etc. what do you feel about resister or non if using computer controlled?