Alright well I've decided to go through with the nitrous setup prior to next year's turbo build.

Things I have or are on order/in mail:

Walbro 255

LC-1 wideband

NX wet nitrous kit w/bottle heater, purge, blowdown, window switch, wot switch. (comes with 35-50-75 jets)

Things I don't have:

Plugs. I have questions on this for ONLY people who are spraying a 3.5 and have experience with trying different plugs. Have you ran 1 step colder with a 125 shot? Did that work out for you? Otherwise I'll have to bite the bullet (N/A power loss) and go with 2 step colder.

UTEC. This is coming in either december or January... I'll be able to play with timing and my base A/F to help with the bigger shot.


Big questions: Obviously the question about plugs from above.

Timing. I've seen some talk about the 3.5 doing pretty well with stock/advanced timing on spray. I currently have the 2 degree advance from a consult II, and I'm curious if anybody has run a 75 shot with the small advance?

For the bigger shot, which will hopefully be in right after I setup nozzles for the 75 shot, has anybody been able to run completely stock timing on a 125 or 150 shot? I'm thinking with the wideband I can get my A/F right, but i can't do better than stock timing until I have the UTEC installed.

Just to confirm, I should be looking for a 12.5-12.8 A/F while spraying, correct? My current N/A A/F runs around 10.5-11.0:1 and I am thinking I will need to use smaller than reccomended fuel jets to lean it out a bit when spraying for the best power. Does anybody have advice or reccomendations for tuning A/F with fuel jets?

 

Hmmmmmmmmmm! not easy to answer easily. First, I have run 2 step colder plugs without sacrificing N/A power. So its not something to worry about.

Timing: I ran a 75 shot with a 10.98 time and no timing reduction. I reduced the timing to 22 deg for the 200 shot. I would be more concerned with the a/f than the timing.\

As far as a/f I would lean towards being richer as it doesn't seem to hurt power even in the 10-11 range. Trying to run 12.5 on spray is a bit generous I would try for a 12 or high 11.

 

Crazy man.... over 3+ years I've run a 150-shot on a 3.0 and on my latest 3.5 (also 175 shot, but that's a secret). It still uses the stock '99 ECU and timing. I used copper 2-step-colder plugs on the 3.0 with stock '99 ECU. I now use 1-step-colder copper-core plugs on the 3.5 (cause 2-step-colder plugs only come with iridium centers and I don't trust them - melted some.) I don't believe in the NA loss of power myth. I've never felt any difference with the 3.0. My NGK copper plugs look fine - sidegapped to .035, with cut grounds. see here:
http://i48.photobucket.com/albums/f2...8/DSCN0352.jpg

A/F needs to be between 11.5/1 and 12.5:1 Look in here:
http://www.hotrod.com/garage/113_0411_n2o/index2.html

You probably know this, but Walbro 255 pump, an Aero FPR, and big filter, like 300ZXTT, are really a good idea with higher shots. Power comes from burning fuel - no fuel, no power... no engine..

You can tweak the jets, but if I gotta, go up or down one step at a time.

You also need to consider some reality here - those braided steel lines that come with the 35-50-75 kit are way too small for higher shots. If you put the bottle in the trunk, use a -6AN NX plastic line from trunk to engine, then be sure the solenoids are rated for enough flow for the shot. Use -4AN connectors on each solenoid and 3AN-to-4AN lines to the nozzle, with 4AN hose. NOS makes these. The originals are barely good enough for a 75-shot. Be darn sure the lines have no kinks or sharp bends - fuel or nitrous can be pinched off some and you wonder why you're slow. This happened to me last time out at KCIR - I lost .5 sec. ET because of a pinched fuel line I didn't catch, and I had to raise the combined shot level to 175 to get a measly 12.5 ET. I've since replaced all lines on my dual-stage nitrous setup. Shid happens, I guess. I can testify that spraying a working dual 175-shot on the street is - scary.

Got a 16' 4AN line from trunk to engine now? Take it loose at both ends and try blowing through it. The 6AN is a garden hose compared to a 4AN pinhole line.

 

Thanks for the quick info guys. The 2 of you were exactly the ones I was hoping to hear from!

From all the info, it looks like I'm going to go ahead and do the 1 step colder plugs and run a 75 shot for a few weeks while I gather supplies to upgrade for a bigger shot.

That's nice to hear from both of you about timing. I'll just get the 2 degree advance taken off with a consult and run it stock.

I'll be running some 24.5x8 slicks and my goal is tip top 11s with a big shot. I know it won't be easy to reach, but that's what goals are for.

 

Yup - gotta have goals. Just when I'm ready for a grand finish to the season, the weather goes to H*ll and tracks are closed. Oh, about those 24.5 slicks - pay close attention to the specified rim size - I used 15x8 American Racing Phantom II rims for my M&H 23x15, and that combo weighs 32 lb each, and wheels cost way under $100 each. I put my 24.5x15 M&Hs on 10" M/T alloys, and the slicks do not like that width - I'm getting weird tread wear on them, and the 23x15 M&Hs still look perfect. ??? I'm buying more of the American Racing Phantom II wheels for the 24.5s next.

I would kill for a UTEC set up for absolute ignition timing, but you gotta have a 3.5 flywheel to do that. Maybe I can think of something for my next engine - the one with forged and balanced lower end and Cosworth heads..... guess that's another goal.

You're gonna like the 75-shot - I ran a 12.8 on that. You know that two NX stages give you better control of spray, don't you?

 

Yeah i've been seriously considering just eating the cost of a 2nd kit and running 2 75 shot stages. That would give me the ability to just run a 75 shot on the street (if i spray) and easier traction at the track (not to mention 20-30 lbs worth of nitrous for more runs). Especially since I'll need to upgrade stuff to run a bigger shot on the single kit already.

Thanks for the advice on wheels, I figured I may need to mess around with different wheel combos to see what the slicks work best with. I'm getting one_fast_max 's slick/wheel combo and he's done some good '60 foots on them, I'm hoping I can pull some similar numbers when I get used to launching on them.

I'm pretty excited about the UTEC. I'll run a very agressive N/A tune and have maps for 75 and 150 shots respectively so I can have them a map selector switch away. There's so many fun things you can do with so much engine control. I expect (from watching Jaypee's progress) that with my full boltons and the UTEC tune combination I can squeek into high 12s N/A as well. He has driver mod and TS L-spec reflash over me right now, but with the UTEC I'll just have to improve the driver mod.

 

Really all you need for a second stage is a pair of solenoids, a Shark nozzle (and jets), four more lines, a relay for the solenoids, and whatever you need for Y-adapters for fuel and nitrous. Most can be found on eBay - that's where I got all of the above for my third stage. I use a plastic shallow electrical wall switch box, with four N.O. PBs wired in parallel, set on the floor on the left side to trigger my second stage. Excellent control that way. I use a WOT switch to spray the first stage - and the second stage is also wired so that you need WOT to spray it. Much safer this way.

You know, you may not be able to fit 15 inch wheels on an '03. Have you checked??? At least match the rim width to the slick.

I envy you having the UTEC - I've really got to get me one of those. Really...

 

a 5.5 isn't the easiest to find slick for afaik. i think you need a 17 to clear the brakes. there is NO WAY a 15 will fit on there imo. if you do find some good rims for slicks let me know i'm VERY interested...

 

I ran 15's on my 2k2, just shaved a bit off the calipers, pretty easy. I used Kosei K1's, so it can be done fairly easy.

 

Cool, may have to go with that setup. I don't mind shaving a little material off the calipers. 15" slicks are about the best setup you can go with since so many drag racers run that size.