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View Full Version : how much nitrous is safe at 12 degrees timing



Steves LX
06-06-2007, 02:59 PM
I have a 89 LX that I am currently spraying 75HP dry thru TB. This is a ZEX kit and it automatically adjusts fuel pressure through a fuel jet and vacum. My timing is set at 12 degrees right now. I want to bump up my shot up to 100 HP but according to the tuning sheet that came with the kit it says to retard my timing 2 degrees. And that would actually be retarding it to 8 degrees seeing they use the factory specs. I have a F303 cam and the car runs like absolute dog crap at anything under 12 degrees. As a matter of fact it most of the time stalls out at 10 degrees and when it does idle the whole motor shakes and it idles at around 400-500 RPMS. So can I spray 100shot at 12 degrees advanced safely and w/out detonation or not? My kit is a ZEX 5.0 dry kit part # 82015. I am also using a ZEX traction control window switch. I have it set up to spray from 3000-5500 and to start spraying in 3rd gear and on. I have been considering programming it to start spraying in 2nd gear but even with drag radials I think I will lose traction spraying in 2nd gear ecspecially since its going to start as soon as I hit second under WOT. But I really need to know about the safety of the 100 shot at 12 degrees timing. My engine is as follows:
302 stock block with new rings seals bearings(about 3000 miles on them now. my rods and stock pistons reconditioned)
Edelbrock 5.0 performer intake manifold
75MM BBK TB
73MM C&L MAF
24# injectors
255LPH holley fuel pump
BBK fuel pressure regulator
MAC CAI
F303 cam
WC T5 tranny
Aluminum drive shaft
BBK full length headers 2 1/2 flowmaster exhaust

5.0calypso93lx
06-06-2007, 03:16 PM
Sounds to me like you have other issues if you can't even idle at 10 degrees:confused:

Steves LX
06-06-2007, 03:24 PM
The car still needs to be tuned she will idle at 10 degrees but its rough.

RACEME
06-06-2007, 03:43 PM
I have done it lots of times. I ran a 100 shot at 12-13 degrees of timing all the time. I did use sunoco 94 with NOS octane booster just in case. The difference is that mine is a wet kit so take that as you wish.

YouGotJunk
06-06-2007, 10:26 PM
Heck yeah...Spray the shit out of it!!! Hell before I changed combos...I was spraying probably 175dryshot on about 14 degrees of timing...this was with race gas and about 45lbs of fuel pressure!!

edit: I did have a good pump and 30lb injectors also...but I also sprayed mine AFTER the mass air. It ran good!!

RACEME
06-07-2007, 05:48 AM
Heck yeah...Spray the shit out of it!!! Hell before I changed combos...I was spraying probably 175dryshot on about 14 degrees of timing...this was with race gas and about 45lbs of fuel pressure!!

edit: I did have a good pump and 30lb injectors also...but I also sprayed mine AFTER the mass air. It ran good!!


Mine sprays between the mass air sensor and the throttle body also.

Steves LX
06-07-2007, 08:01 AM
I have mine after the MAF and about 6 inches before the TB. I have a 255LPH holley fuel pump. I have 24# injectore and I am using autolite 24 spark plugs. They are one step colder than the normal 25's. I have my fuel pressure at 32. The ZEX dry kit increses you fuel pressure when you activate the nitrous so I have never adjusted my fuel pressure manually anytime I have sprayed it. I just know that the tuning sheet that cam with the kit bases everything off factory settings and factory setting for timing is 10degrees and with a 100 shot they sat to retard 2 degrees. I really want to keep my timing set at 12 degrees if its not going to detonate or do anything stupid. Yougotjunk this is the kit I bought off of you a few month back. I met you up at Middletown mall.

quik lx
06-07-2007, 08:02 AM
Using the same Zex kit I spray 125 shot with 10 degrees, 91 octane, and 40psi of fuel press (until the spray hits and it pegs my 100 psi gauge.) All this on a stock motor with no problems at all! Just hit the spray for a couple seconds on the way to your driveway, kill the motor and coast in, pull a couple plugs and see if its rich/lean/detonating. I would still bump the fuel press up for safety.

Steves LX
06-07-2007, 08:56 AM
Thats cool. I am only going to bump it up to a 100 shot and since this is a ZEX dry kit I was going to bump up my fuel pressure to around 35-37 psi even though the kit I have meters the fuel pressure on its own. I am going to leave my timing set at 12 degrees though. I am using 93 octane gas. I plan to run at UMTR this weekened so well see how it goes. I am still debating on whether or not to start spraying in 2nd gear or 3rd gear. I just got a set of used DR's and this Saturday will be the first time I use them. I was running on street tires and spraying 75 shot from 3rd gear on. I haven't done anything suspension wise so I guess I am just a little leary of breaking something if I hook good and start spraing to soon.

YouGotJunk
06-07-2007, 10:52 PM
Sorry but you didn't buy no ZEX kit off of me. I've only owned 2 nitrous kits...I sold one to my buddy that was a carb kit and the 2nd I still have...I've never owned a zex kit...probably never would...all that brainbox shit is retarded...put a 200 shot on a button and when your ready...spray the fuck out of it!!!!!!!!!!!!

Steves LX
06-08-2007, 07:50 AM
yougotjunk thats my mistake.

YouGotJunk
06-08-2007, 02:19 PM
ah it isn't no big deal...I had to think about it for a minute, lol. I knew I never owned a zex kit though....anyways...SPRAY THAT BITCH!!!

Timido
06-10-2007, 01:33 PM
rule of thumb is tune the car to what ever it likes on motor. Then add nitrous and fuel by either a wet kit or how ever a dry kit ups the fuel. Pull 2 degrees for every 50hp of nitrous.

Rick93coupe
06-10-2007, 03:31 PM
I have mine after the MAF and about 6 inches before the TB. I have a 255LPH holley fuel pump. I have 24# injectore and I am using autolite 24 spark plugs. They are one step colder than the normal 25's. I have my fuel pressure at 32. The ZEX dry kit increses you fuel pressure when you activate the nitrous so I have never adjusted my fuel pressure manually anytime I have sprayed it. I just know that the tuning sheet that cam with the kit bases everything off factory settings and factory setting for timing is 10degrees and with a 100 shot they sat to retard 2 degrees. I really want to keep my timing set at 12 degrees if its not going to detonate or do anything stupid. Yougotjunk this is the kit I bought off of you a few month back. I met you up at Middletown mall.


If the manufacturer tells you to pull 2 degrees, you'd be safer to pull the 2 degrees. They tell you that to keep it from doing anything stupid. I don't understand why everyone thinks it doesn't apply to their engine. Good luck.

Kwik92GT
06-13-2007, 10:18 AM
Just an FYI, you can pull out too much timing and have very bad results too. Stick to what the manufacturer suggests and you'll be fine.

Steves LX
06-13-2007, 01:32 PM
Well I just did what quick lx said to do I drove up the street and turned around and came back and sprayed a 100 shot in 3rd gear for about 1 1/2 seconds or so and killed the car and coasted back in the parking lot. I pulled 3 differn't plugs aand they all 3 looked the same. They were all a dark rust looking color. So any help with that would be appreciated

quik lx
06-13-2007, 02:36 PM
That is good...keep sprayin!!!!! Brownish/tan is a happy engine!

Timido
06-14-2007, 10:23 PM
http://www.dragstuff.com/techarticles/reading-spark-plugs.html