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Discussion Starter #1
Alright.. so some of you guys know that ive got some experience with Nitrous Oxide and EFI (approximately 6-7 years). On the flip side... i have nearly NONE with carbs. Ive seen a few... just a few cars with a healthy amount of Nitrous, and a carb... with a 5 speed backfire between shifts through the exhaust. My question is simple.. is something like that common with carbs, Nitrous and manual transmissions? Its never happened to me with EFI and Nitrous at all... so im just curious.
 

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I've never had backfire issues with shifting and carburetors. I don't use any fancy window switches or fuel pressure switches or multiple fuel pumps either. One thing to watch with plate systems is fuel distribution. Once you get in the 200+ horsepower range you need to stay on top of plug reading and do it properly. Number 1 and 5 cylinders seem to have the worst distribution problems. Even naturally aspirated those cylinders run leaner and hotter than the rest. A fogger will cure any distribution problems but it also comes with a price. If you shoot big amounts thru a plate you might want to experiment a bit with spacers, etc. There are some good plates out there that are suppose to help with distribution issues. That is something else to look into.
 

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Yeah, plate technology has come a long way. There are 360 degree spray plates, twin bar spray plates and the plates are drilled in such a way as to direct fuel in specific directions towards the front cylinders.

As for the backfire issue. this is why it happens. When people power shift with nitrous and no window switch, they hit the rev limiter for a split second with the nitrous still on. The rev limiter cuts the ignition and thus unburned fuel and a little nitrous get dumped into the hot exhaust and you get some pretty decent backfires.

The solution is to run a window switch with a lower rpm (100-200 rpms) than your red line and shift at or before the window switch. Thus the nitrous gets cut before the ignition. Alternatively, if you just shift normally, the nitrous will be off between shifts.
 

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Discussion Starter #5
Also, talking about plate systems.... Do either of you know, or have any experience with the ZEX Perimeter plate, or anything from Nitrous Pro Flow? Im weighing those two manufactures back and forth. I was also looking at Speedtech.
 

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Also, talking about plate systems.... Do either of you know, or have any experience with the ZEX Perimeter plate, or anything from Nitrous Pro Flow? Im weighing those two manufactures back and forth. I was also looking at Speedtech.
Never used ZEX but they are not highly respected. Nitrous Pro Flow is some good stuff. NX makes some good plates too.
 

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Discussion Starter #8
Never used ZEX but they are not highly respected. Nitrous Pro Flow is some good stuff. NX makes some good plates too.
Oh wow, i was under the impression Zex had some good equipment (perimeter plate). I like Nitrous Xpress, ive had excellent results with them and their staff with all my EFI cars. I like Nitrous Pro Flows plates and their equipment.. just didnt know if you had any experience with them seeings as your a carb/N20 guy. Thanks Darrell.
 

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NX makes a similar perimeter plate and a 2-stage perimeter plate. see links above.
 

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Do you have any experience with either of these? They look good... but i dont want to make a decision based on what looks good.
No, I don't have any first hand experience with these particular plates, but I do have a gemini spray bar plate from NX and the quality is great.

These are relatively new products, but NX stuff is top notch in my book and their custom service is hard to beat.
 

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Discussion Starter #12
No, I don't have any first hand experience with these particular plates, but I do have a gemini spray bar plate from NX and the quality is great.

These are relatively new products, but NX stuff is top notch in my book and their custom service is hard to beat.
I agree 100% about their customer service and quality. Do you know if the NX G-plate has burst panels? Thats something i like about the Nitrous Pro Flow plates.
 

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Do you need burst panels with a CARB??? Almost any carb worth its salt has power valve blow out protection or no power valves. backfires just go straight out the carb, no harm in that as long as the throttle is open (you will be running a WOT switch, right?).

Personally, I've never had a nitrous backfire in the intake with my NX stuff.
I don't think they make anything with burst panels, don't know of anyone that has burst panels on their car.
 

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Discussion Starter #14
Do you need burst panels with a CARB??? Almost any carb worth its salt has power valve blow out protection or no power valves. backfires just go straight out the carb, no harm in that as long as the throttle is open (you will be running a WOT switch, right?).

Personally, I've never had a nitrous backfire in the intake with my NX stuff.
I don't think they make anything with burst panels, don't know of anyone that has burst panels on their car.
Absolutely, i'll be using a WOT switch. Bare with me.. im not affiliated with carbs and Nitrous.. i thought it was a good idea from what some people tell me. Im not sure... but isnt a power valve better to have for a street car? Or no? Hows drivability without one?
 

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A power valve is a vacuum controlled valve that operates the enrichment fuel circuit. An all out race carb is designed for racing and is tuned for WOT. Without a power valve, driveability will kinda suck since it will be rich all the time. most powervalves are a lot better than they were 20 years ago and rarely blow out from a backfire.

Anyway at WOT a backfire will not hurt anything since it has an exit straight out the top of the carb...as long as you don't have a flammable air filter on there, everything is good.
 

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Discussion Starter #16
A power valve is a vacuum controlled valve that operates the enrichment fuel circuit. An all out race carb is designed for racing and is tuned for WOT. Without a power valve, driveability will kinda suck since it will be rich all the time. most powervalves are a lot better than they were 20 years ago and rarely blow out from a backfire.

Anyway at WOT a backfire will not hurt anything since it has an exit straight out the top of the carb...as long as you don't have a flammable air filter on there, everything is good.
Okay, i was a little worried about that... thats why i asked about the burst panels. So, for a street/strip car (my plans) i should keep the power valve?
 

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my buddy has been using Zex's plate kit on his nova for a couple of years, he's been spraying a 300 shot on pump gas an has been running traction limited 10.0s at 138 mph almost every weekend and has never had any problems with the system
 

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Alright.. so some of you guys know that ive got some experience with Nitrous Oxide and EFI (approximately 6-7 years). On the flip side... i have nearly NONE with carbs. Ive seen a few... just a few cars with a healthy amount of Nitrous, and a carb... with a 5 speed backfire between shifts through the exhaust. My question is simple.. is something like that common with carbs, Nitrous and manual transmissions? Its never happened to me with EFI and Nitrous at all... so im just curious.
Do you have a rev limiter, and if so are you power shifting?
 

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Discussion Starter #19
My last car had a rev limiter. I dont powershift.. in any of my cars, atleast not anymore.
 

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I've seen carbs blown off the intakes with nitrous backfires WITH burst panels. I wouldn't let burst panels sway your decision.
 
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