I got four full passes on KCIR's track - the day was sunny, no winds, about 55 degrees - pretty darn nice day after 1 PM. Dave B, you missed a good one! A personal best of 13.281 / 103.19 - and ate a 200x GTO in the process! Not too bad for a car that showed 211 HP on a dyno yesterday!

I made my first pass with the BDF DRs 255/50/16s on the car - because I wondered how well they would do. They did badly compared to my M&Hs.

The water box got a workout - smoked em' badly - and on launch, they spun madly. I really didn't have much traction until at least the 1/8 mile... then the second-stage 75-shot couldn't be used at all. Lots of spinning - got a 14.156/97.25 time. DRs are out, and these suckers have 9.7" on the ground!

All these passes were on M&H 23/8.5/15 slicks. Much better.... I need better tires, though - too much spinning... When warming up the M&Hs, I was bouncing off the fuel-cut limit. Lots more smoke - and now I use shoe polish to put "MAXIMA" on the back glass so the tower knows my car is not an Altima...

R/T..........148...........-.093.........096....
60'...........1.947..........2.012.......1.998..
330'.........5.507..........5.571.......5.516..
1/8..........8.476..........8.566.......8.500..
MPH.........82.01..........82.22.......82.26...
1000........11.080........11.171......11.103..
1/4..........13.281........13.377......13.314..
MPH.........103.19........102.14......101.16.
................^
( GTO=14.623ET/96.64MPH)

It turned out that something CMAX said in an earlier thread gave me a clue - I sprayed right into a 75-shot at launch ( spinning) and got into the second 75-shot immediately, but I had connected a LED assembly (by MetalMaxima ?) to the MSD-controlled Shift_Fast unit (set at 6400 this time) as a shift light, so when the LED bank flashed (that sucka works in the daylight!), I let off the second stage and the tranny banged into the next gear - hard. Much better than leaving both stages on all the time. Obviously streetzlegend's idea was right - I should gate the second stage through the Shift_Fast.

I set the slicks to 15 psi this time, instead of 12 psi, and the car felt much more stable through the quarter-mile.

Not back for a stock V6 with an automatic.........

 

nice job man, i bet thats a good feeling getting a better time just before the seasons over, i can see u in the 12s next season

 

Congrats on the new best. Conditions today were quite nice. The DA was in the 100' range. I'm kicking myself for running last Sunday, but not today. I might try and go next Sunday if the conditions are good.

 

Yeah - let's hope weather will allow.... Traffic was light today. There was a Ford flathead dragster there today! A blast from the past!... Bet I'm older than the engine, too......

 

Maybe even next Sunday - the last KCIR track day this year. I have one or two tricks left. Heh...

 

HEy grey99 good times! Glad to see your still able to hit the track.. Kepp us updated when you hit KCIR again.

 

oh man, your getting closer and closer to 12's!! congrats. So you finally tried letting off nitrous at the shifts like i said. to me i think its better, because if ur putting down alot of power while shifting even with DR mod our auto still always going to slip a lil bit, so by not spraying when it shifts, the shift is even faster because no slip. so congrats dude, hope you get into 12's next track visit.

 

Hey - how's the new wife? Yup, no snow here yet - and one more track day left in 2006..... XXX that's me crossing my fingers for luck...

 

Yep - that does work better, it seems... The shifts were real positive and hard when I let off the second-stage switch for a second. It won't be any great trick to connect the grey wire on the MSD 8969 to the ground path of the 2nd stage relay. When the programmed rev limit is reached, the 2nd stage is cut off. Duh. I was shifting at 6400 today - worked great..

The tranny shifts great while spraying through a continuous 75-shot, so I'll leave that alone, I think.

I was on the local Buick Club's dyno Saturday, and found the A/F ratio drops from 14 to 12 on the first stage and to 10 when the second stage is kicked on. That seems to mean that either stage drops the A/F by about 2. Hummm - I wonder if I reduced the fuel pressure a couple of lbs, then the A/F would stay up to 13 or so....... Either that or the nitrous feed line can't handle the full flow for 150-shot. Something to think about, I guess.

 

great job, hey 211 at the dyno that was n/a or a typo

 

SOB! I recalculated conditions and the DA was actually -600!!!!!!!!!!!! Last Sunday when I raced the DA was 1,200. Damit! I always miss these amazing track days. I surely would have gotten into the 100mph club today

 

Nope, that dyno read 150 HP as N/A and read 211 when spraying a total 150-shot. Sound a little strange to you ??? Especially with the 13.281 ET today, backed by a couple of 13.3s....

I have a video of the two 150-shot pulls on the dyno, and the two stages are quite obvious when they spray... and yet the graph shows no jump in power. I hit the second stage at 5000 on both pulls.

They were testing some monster Buicks that day, and there were two that spun tires on the dyno. I suspect that is what happened to me, since the sudden nitrous hits don't show on either graph.

I'll have to repeat the same pulls - on another dyno... This was a Dyno Dynamics Dynamometer, run by a reputable local speed shop. We shall see.. At least the A/F ratios were instructive. I should get one someday.

 

Cool - can you calculate me into the 12s ???

It was a pleasant day - and it looks like next Sunday will be the same. One last chance.......

 

everything is good. we got her a 99 SC maxima, and I am half way done building the 3.5 right now. I have all the internals and hope to be running this jan. I will post a thread of my build this december

 

perhaps its time to get two bottles =), to have a true dual stage. having one bottle and using two nitrous solenoids might alter or limit the amount of nitrous coming out the nozzle. Or call NX and ask them what size line they recommend for two nitrous solenoids.

 

You know, I thought about that yesterday. If the A/F is fine when WOT and N/A, and it drops 2 points with the first stage and down to 10:1 on the second identical stage, then there is too much fuel being delivered. The bottle has a NX heater/regulator attached, so pressure stays up. My installation is conventional - a Y splits the nitrous line from the trunk and goes to both solenoids etc.

Great - something else to figure out.....

 

Wow - modified-Maxima heaven. Seems like there are a lot of those in Utah. Lucky you.... Please keep the rest of us 3.5-wannabes informed..

 

You might want to run a smaller fuel jet for the second stage.

 

Nice runs Grey... -600 ft DA is awesome!

 

Yes - that is a possiblity.... but the problem is - why does this happen? Dropping nitrous pressure because of too much flow? Fuel pressure too high during spray?

The closed-loop A/F is 14.7, I think - don't have charts here - but going WOT drops it into the 13s, spraying the first stage drops A/F more, and activating the second stage really drags it down. I think the AERO AFR is set to 46 psi - which might be some of it...

 

Dandy - see how much USA nitrous it takes to equal one Canadian N/A car ??

I'm not a big believer in DA, but it was a great day to be outside and spinning tires. But, maybe, underground drag racing will become popular on the days DA is low....

Even the new Lotus sport coupe that showed up ran a 13.1 quarter-mile, bone stock. That car was not three feet tall, but sounded like a Ferrari.... that ripped-sheet sound some european cars make. Quite a bit different than the real-old-school Ford flathead dragster that was out there.

Can't wait to see what you do next.

 

Well the bottle looses pressure as one sprays, thus the mixture turnes rich. And once you add the second stage from same bottle I guess it causes the pressure to drop even faster then before thus causing you to go even richer. But what I really think is happening is that the first stage drops the a/f into the safe zone for boosted and juiced ap[plication which is around 11.5-12.5 area. But since the second stage doesn't know that there is already another stage working which already dropped the ratio into safe area, thus it adds more fuel thinking that you are in optimum na ratio but you are actually already in optimum juiced ratio, so it just adds too much extra fuel and thus you are adding to the already richend ratio. That is why you are in the 9s or 10s. Also for a 75 shot you only need 24 size fuel jet but for 150 only 35 jet is needed. But you are using a 24+24 size jetting which is 48. That much fuel jetting is needed to run 200 shot.



Wow, I can't believe I wrote that much and I hope it makes sense. If not hit me up on aim.

 

OK - I see your point about the fuel jets, but... the actual area of each jet is pi times r-squared. A 24-jet has an open area of (12 * 12) * 3.14 = 452.
Twice that (for both jets) is 904. (not sure of the units here). A 35 jet is (17.5 * 17.5) * 3.14 = 962. Two 75-shot jets are about 6% leaner than one 150-shot jet, in this case. Maybe. Wow - fun with a calculator....

When WOT with a stock ECU, the car is in open loop, and the first stage and second stage have their own lines and jets and nozzles, except - the fuel solenoid lines go to a fuel manifold I built, and the nitrous lines go to a NX Y-connector which splits the line from the trunk into two lines which then go to each N2O solenoid.

What if NX set the jet sizes to do what you said ? - richen up the mixture for one nozzle to make it safe for the engine - and when the second stage is ON, the mixture is then richened even more - BY NX DESIGN ??

I think you've got a truth here.. I don't have the dyno A/F charts here, but the A/F drops about the same for stage 1 and stage two, when both are set for identical 75-shot. Leaning out the second stage might be the answer....

Hummmmm....

 

I would probably try the 20 jet for second stage. Unless you can just lean out the injectors upon activation of 2nd stage. You have EU?

Edit. This actually reminds me of an old math problem I had in 7th grade. Don't even think of asking me what the answer is and how I got it because I don't remember it, but the principle is the same. Imagine you have one house and it requires a 1" diameter piping for waste removal from the toilet. How they add another house that also requires a 1" diameter piping for waste removal. So instead of having two different piping setups that run to the waste management facility they want to combine both houses to use same source. One would think that since 1" diameter is needed in each house then a 2" piping is required but in reality a 1.25-1.5" piping is only required to flow the mount needed for both houses.

Thus I think same principle is applied here to the amount of fuel needed to sustain both stages.

Now I am trying to figure out how it applies to your situation.

 

Well, no - I have a stock ECU, no A/F meter and am living on luck and my third engine... You are right about the plumbing problem - that's the same thing I just went through with the fuel jets - area of the opening, sewer or fuel, is one-half the diameter of the opening, squared, and multiplied by "pi" , which is 3.14(15926536)... The two small ones have less area than one large one. ???

Maybe a 22 jet for starters - I don't want to go lean.. Thanks for thinking this through with me.

 

I think it would be a smart move to try the 22 and since you already have the 20 jet try that if its still not enough.

 

I still suggets you purchase a second bottle. dosnt have to be another 15lb maybe just 10lb. and use that 10lb as ur 2nd stage. This way you dont mess with your nitrous jets. I still say u should also call NX and see what they recommend.

 

I think I am losing my nitrous title, take it easy. You're doing great keep it up.

 

Hey, thanks, but you know I'm just one step above clueless.... I probably need to do at least a wideband.

I'm a plodder - one careful step at a time, pick up the pieces, figure out what's next.. And listen to the *.ORG.

 

Yup - I've got a bucket of jets - two sets of most sizes, and single sets for 100 and 150-shot. I like trying the 22 first - just a little leaner would be good without a A/F meter..

 

Actually I do have both a 15lb and a 10lb NX bottle. I would need a bunch more stuff - bottle mounts, heater/pressure switch kit, another 16' hose, purge solenoid... I just got both refilled tonight, so I'm good to go for Last Sunday Of The Year.

 

Well, soon my friend. im coming for your nitrous title!!

Since your taking lil steps at a time, and trying to not burn another motor. why not just spend a couple $100's and get a tuning device or wideband? Shoulda been your first few mods. I learned the hardway, after being beat on by other 4th gens (n/a runs) i finally now tuned with wideband and vafc2. its well worth every penny.

What I am going to do, and so should you is, when i do nitrous runs at the track, lower all my corrections the same amount, to bring the curve down to the 12's or high 11's. that way when i spray I still maintain a nice flat a/f curve, and therefore putting down more power since u dont have them rich or too lean spots.

 

Ah, youth. I quit drag racing in 1970 - my last machine was a 850cc nitromethane-burning Triumph drag bike. No rice...

Now, I don't care about NA performance - it's too slow.(don't tell Dandy I said that). My personal goal has been to get into the 12's w/stock ECU and without weight reduction, turbo, supercharger, datalogging, piggybacks, and various pieces of instrumentation. A few engines along the way - OK.

I am now interested in A/F readings, long-tube headers, wider slicks, and a 3.5L motor. Most of that is for next season, after the snow is gone. For now, I think I'll lean out the second stage for next Sunday..... and hope it doesn't snow.

 

I'll be waiting for the post

 

How about a double-shot dyno in the meantime ??

http://s48.photobucket.com/albums/f2...t=Dscn1457.flv

 

I'm a huge believer in DA. Everytime the DA has been in the sea level range vs the more normal 1,200-2,000, my cars are about .18-.20 seconds and 1-1.5mph quicker. I've always ran my bests in the Fall when the DA was below 500'. Two weeks ago, the best my G could muster was a 14.42@99.87mph in 1,200' DA. We'll see how it runs this weekend if the conditions hold (low 50s, high pressure).

Was it carbon gray in color and have an aftermarket exhaust? If so, that was a friend on mine. It has cut 1.6 60 foots on the stock rubber. Yeah, the advantage of RWD and a midengine layout.

 

Dave, hope to see you there.... So you have the DA figured out? I guess the concept escapes me. High pressure is good, cool temps are good, sunny sky is good, low winds are good, - that seems logical....

That's the Lotus.... it sounded mean, and seemed so .. small... and so cool. That's gotta be a babe magnet, right?

I'm ready for Sunday.

 

well i just mentioned my gains and experience with n/a to give you an example of how important and beneficial it is to adjust your a/f. i dont really drag race, too scared of getting caught or hurting someone, I just open up when ever i have free road all for myself or quick lil runs with other max buddy's

 

I wasn't slamming you for tweaking your NA setup - that's invaluable experience if you get it right. I just don't want to do that now, as I explained back a bit...

Back in the day, we raced serious cars on the street - that was the era of real muscle cars in the late 60s and early 70s. 3 AM races were how we spent the weekend.. that and lots of liquor... and drive-in movies... I had another nitromethane bike for serious street work - imagine cruising drive-ins with an open-header bike belching blue flames out of the pipes.. I tuned that bike by drilling out the jets with different drill bits and reading the plugs.

So, once you've done all the stupid stuff on the streets and highways, raised a couple of families with a couple of wives, built a few houses, done college and careers, got kids through college, then when your 83-year-old mother dies, you can decide to make her car into something special - and fast. Truth.

It would be easier to buy a 600 HP crate engine from Jeg's, bolt it into a '55 body, do tranny, rear end and the other good stuff, and have a 10-second car again. But what the heck, I have a Maxima.