Nitrous question

[4EYES31]

I've been thinking about adding a 150 shot to my striker build after it's done, and broken in, but I do have a few questions. I know that you have to retard the timing like 2 degrees for every 50hp, but do you take that timing out of the initial or the total? My Mallory distributor has like 24 degrees all in before 3000, and as far as I know, I can't change the curve in any way. So with my initial set at 10 deg. And with 24 advance, that gives me 34 total all in by 3000. So for a 150 shot, I would need 28 degrees total? Am I close?

[kiwi]

thats right....watch your AF too. And it would be good to "ramp it in" during peak torque and all in after....

[merk]

every set up is different on timing . What jet spread you going to run? For a 150hp i suggest around a 65 n 55 f flowed ay around 5.5 psi . And its easy to add timing later than to add ring lands . So whats the rest of the combo ? Let me know and ill tell you a pretty damn good start point .. I may have sprayed a sbf or two lol

[4EYES31]

[QUOTE=merk;1554472]every set up is different on timing . What jet spread you going to run? For a 150hp i suggest around a 65 n 55 f flowed ay around 5.5 psi . And its easy to add timing later than to add ring lands . So whats the rest of the combo ? Let me know and ill tell you a pretty damn good start point .. I may have sprayed a sbf or two lol[/

347 stroker, dart block, crower forged crank, scat forged rods, je flat-top pistons with 10.5:1 compression, comp cams 280 magnum roller, .544 lift, I think? afr heads, edelbrock rpm air gap intake, Holley 750 double pumper, unknown jets, 1 inch carb spacer. 1 5/8 long tube headers, t5 transmission, 3.73 gears, 275/60/15 mt dr, mini tubs. I haven't chosen plugs for this car yet, everyone keeps saying I need colder plugs to run nitrous?

[merk]

[QUOTE=4EYES31;1554532]

every set up is different on timing . What jet spread you going to run? For a 150hp i suggest around a 65 n 55 f flowed ay around 5.5 psi . And its easy to add timing later than to add ring lands . So whats the rest of the combo ? Let me know and ill tell you a pretty damn good start point .. I may have sprayed a sbf or two lol[/

347 stroker, dart block, crower forged crank, scat forged rods, je flat-top pistons with 10.5:1 compression, comp cams 280 magnum roller, .544 lift, I think? afr heads, edelbrock rpm air gap intake, Holley 750 double pumper, unknown jets, 1 inch carb spacer. 1 5/8 long tube headers, t5 transmission, 3.73 gears, 275/60/15 mt dr, mini tubs. I haven't chosen plugs for this car yet, everyone keeps saying I need colder plugs to run nitrous?

yes best bet for a good nitrious plug for your power app would be an autolite number AR3933 you can also go one step colder to AR3932 these are a power adder plug and wont be prone to detonation . Depending on ignition Id gap them at 32-34 thou if using a pretty good coil and box .
What do you have the timing set at? That will make a difference on the igntion retard you need so hear are a few more questions
What fuel are you going to spray on?
Whats your total timing currently?
Whats the igntion?

Do you or anyone you know have a flow tool for setting fuel pressure ?
So far tune info=
- Spark plugs - Autolites # AR3933 or Ar3932 gapped around 30 thou (because of unknown igniton)
plate jets- 65 n 55 f With flow pressure at 5.5 psi
- total timing around 26 degrees (fuel dependant and dependant on your current total timing)

[4EYES31]

[QUOTE=merk;1554756]

yes best bet for a good nitrious plug for your power app would be an autolite number AR3933 you can also go one step colder to AR3932 these are a power adder plug and wont be prone to detonation . Depending on ignition Id gap them at 32-34 thou if using a pretty good coil and box .
What do you have the timing set at? That will make a difference on the igntion retard you need so hear are a few more questions
What fuel are you going to spray on?
Whats your total timing currently?
Whats the igntion?

Do you or anyone you know have a flow tool for setting fuel pressure ?
So far tune info=
- Spark plugs - Autolites # AR3933 or Ar3932 gapped around 30 thou (because of unknown igniton)
plate jets- 65 n 55 f With flow pressure at 5.5 psi
- total timing around 26 degrees (fuel dependant and dependant on your current total timing)

My initial timing is set at 10, total timing is 34. The distributor is a Mallory unilite with 24 degrees of advance all in by 3000 rpms. The timing curve is non-adjustable. The fuel will be 93 octane.

[4EYES31]

The ignition coil is a msd blaster 2 coil.

[4EYES31]

Also, my Mallory distributor doesn't require an ignition box, everything is inside the distributor.

[merk]

maybe back the timing down and lil to 25 total because of the fuel . Tuning is simple buy a few extra plugs before you make a pass put a fresh plug in say number 1 since its usually the leanest and easiest to get at . make a pass shut it off as soon as u can and pull over on the return road and pull the new plug out put a old one back in drive in then you dont dirty plud and you can actually read it . and beable to see the fuel line with either a flashlight and magnifing glass or jjust cut thethreads off the plug so u can see the porselin . Ill try and find some examples to give you a better idea

[bigblockfox]

You might try a NGK plug also. I love autolites but reading a NGK plug is 100 times easier. When you make a pass if your gonna check a plug shut it off right after the stripe. If you let it idle or try and drive it down the return road if can give you a false reading on the plug. I love autolites for N/A but for nitrous NGK gets my vote.

[bigblockfox]

What size afrs do you have?

[4EYES31]

I have 205cc afr's. I traded a set of E7TE, and Windsor Sr heads for these.

[merk]

You might try a NGK plug also. I love autolites but reading a NGK plug is 100 times easier. When you make a pass if your gonna check a plug shut it off right after the stripe. If you let it idle or try and drive it down the return road if can give you a false reading on the plug. I love autolites for N/A but for nitrous NGK gets my vote.

ngks are a bastard to read timing on the strap since it has to burn the cadium coating on them off before it will give you a proper reading and ngk race plugs are a few bucks more expensixe . Autolites are easier to read timing on the strap than a ngk unless you sand the cadium off the strap prior to the pass

[bigblockfox]

ngks are a bastard to read timing on the strap since it has to burn the cadium coating on them off before it will give you a proper reading and ngk race plugs are a few bucks more expensixe . Autolites are easier to read timing on the strap than a ngk unless you sand the cadium off the strap prior to the pass

I made a mistake on my post. If your tuneup is off or something goes haywire the NGK plug will burn the strap off before you hurt anything "usually". The autolite strap will not burn as easily.

[PaceFever79]

I'd go with an MSD digital 6+

That way you can have normal advance for when you are running it NA
Also allows you to launch NA then retard as you bring in the N2o
This gives you the best of NA/traction/and boost

[bigblockfox]

I'd go with an MSD digital 6+

That way you can have normal advance for when you are running it NA
Also allows you to launch NA then retard as you bring in the N2o
This gives you the best of NA/traction/and boost

Why would you leave on motor? If you do it will be slower. Leave on the bottle and let em hang

[PaceFever79]

Why would you leave on motor? If you do it will be slower. Leave on the bottle and let em hang

All depends on traction....

It also makes for a better street / strip package.

Manually retarding the timing is going to kill your NA performance.

[bigblockfox]

All depends on traction....

It also makes for a better street / strip package.

Manually retarding the timing is going to kill your NA performance.

It would be best to lock the dist out. With the digital 6 you can pull timing with the nitrous is activated. On my car we locked out the dist and ran very little timing in it. Turd on motor (14.40s) beast on the bottle (10.9 but I use a 6a box.

[PaceFever79]

Here's the cool thing.. If you use the Digital 6+ with throttle switch and a shifter button,
you can have full NA power, and use the nitrous boost at will when you want it, when you
have the traction and space. It makes the system street friendly.

[PaceFever79]

Here is a wiring schematic (substitute the window switch for a shifter button switch)

[PIGBOY]

But remember when running self activated to be sure and have a load and above 3 grand is pretty safe. Below these peramiters is where people get into puddling do to no flow and we see big boom and parts fly. I raced with nitrous for many years and never used a purge and always street raced and it is a wonderful kick at red lights at the lower rpms as long as done correctly and loaded. You can effectivly purge just by doing what was just described in the burnout box and your good to go.

[ry4ns302]

FYI:Mallory 685 embarrases the msd "king of the hill" box. Check out what the big boys on yellowbullet are preferring lately

[4EYES31]

Well after doing a little more research, and actually taking my distributor apart, there is a mechanical advance under the trigger wheel, so the curve is adjustable, if I choose.

[4EYES31]

maybe back the timing down and lil to 25 total because of the fuel . Tuning is simple buy a few extra plugs before you make a pass put a fresh plug in say number 1 since its usually the leanest and easiest to get at . make a pass shut it off as soon as u can and pull over on the return road and pull the new plug out put a old one back in drive in then you dont dirty plud and you can actually read it . and beable to see the fuel line with either a flashlight and magnifing glass or jjust cut thethreads off the plug so u can see the porselin . Ill try and find some examples to give you a better idea

I'm confused. If I back my total timing to 25 degrees, then my initial would be 1 degree, correct? My engine wouldn't run on that. I've tried to tune my previous 331 with more initial timing, but it didn't like any more than 12, and any less than 10. I've been reading how to recurve my distributor, and it seems simple, but adding too much initial timing would cause the starter to drag? I can change the springs in my distributor, and adjust the baseplate to give no more than 16 degrees mechanical advance, but I wouldn't be able to exceed 10 degrees initial timing to stay close to the 25 total that you suggested....Help!

[4EYES31]

It would be best to lock the dist out. With the digital 6 you can pull timing with the nitrous is activated. On my car we locked out the dist and ran very little timing in it. Turd on motor (14.40s) beast on the bottle (10.9 but I use a 6a box.

How could I lock the distributor? Would that affect street driving?