SDB

iTrader: (7)

I currently run 62 N20 jet and 31 fuel jet. Stock 150 jetting was 62/33, ran ral rich (9-1 AF ratio). Now its at 11.5 AF ratio. I want to lean it out just a little more, and have a 28 fuel jet (which seems a little too small). Should I go with a 30 or 29 fuel jet, or slightly up the nitrous jet?

Car is 04 GTO with CAI and fuel pump, 150 wet NX kit. Car runs great, 02 readings are 730-880 under load, and I get a little KR at the shift and in middle to top of 3rd gear. I tried taking out more timing with timing tuner, but KR was still there. I think I just need to desensitisize the knock sensors a little more to be honest. I just changed plugs yesterday, old ones were not a good indication of how car is, since I was running them untuned and real rich. I will pull my new ones soon to check.

Get up to 4 degrees KR under nitrous load, but get about the same on motor, whcih is why I think the sensors are too damn sensitive. I will try some Torco Accelerator and see if that calms down the KR. Custom tune I had done did bump up the high/low octane tables a bit. Also have 160 thermostat.

Thanks

SDB

V6 Bird

iTrader: (15)

Before you do anything fix the KR first. BOOM BITCH if not. Could be the PVC system getting some oil into the intake...Im really not sure on the GTO stuff yet.

NXRICKY

iTrader: (1)

OK correct me if am wrong here. IF you see a little KR should your stock computer being backing the timing down for you. I thought that was the reason for knock sensors. TO run the maximum amount of timing, does not the computer add and remove timing as need for the maximum performance.
Now as far as the leaning out a tune up.

We must first find out why you are so rich. so I have some questions.
What is the bottle pressure.?
How much is in the bottle during the pull?
Bottle mounting/ where, angle etc.
How much power did that tune up make?
Nozzle location?
These will help me out.
Ricky

SDB

iTrader: (7)

bottle pressure was fine, 1050 psi, full 15 lb bottle, mounted with supplied brackets in trunk of GTO, runiing filter, NX single fogger nozzle kit (20920), timing tuner, walboro FP (gets about 60-62 psi at rail), FPSS, NX bottle heater, NGK TR plugs gapped at .038, etc. Put nozzle directly in front of TB in the straight part of the air intake tube (elbow, custom made CAI, probably about 3-4 inches from the beginning of the TB housing, pointed straight at the TB).

Made about 120 rwhp on the 150 shot with 62/31 jetting, with 11.5 AF ratio (04 GTO, automatic, IRS, stock converter and stock exhaust)...

pressure was pretty concsitent through the pulls, I let the automatic botle heater get it back to temp inbetween dyno pulls. We desensitized the knock sensors a little, tuned out the rear 02 sensors, increased the high/low timing tables, removed TM, turned fans on lower temp, put in 160 thermostat. My 02 readings per EFI Live program were 730-880 or so furing the nitrous runs, which seem about right.

I have heard that 04-05 GTO's knock sensors are very sensitive, which is why we desensitized them 15% or so. When I used the timing tuner to remove 1-2 more degrees of timing both on motor and on nitrous, the EFI program still showed the same type/amount of KR, which leads me to think it isn't a timing issue, but maybe a sensitivity issue (not sure though). I plan on trying some Torco octane booster (worked well in my Camaro) and see if this helps out before I desensitisize the knock snesors any more. I get the KR immediately in 1st, then it goes away, then at the shift (that doesn't bother me), and then uper rpm of 3rd gear.

NXRICKY

iTrader: (1)

Ok I do not see a reason for the rich condition. One more thing, lets do a flow test to make sure you are getting the proper amount of nitrous. If you would like to do this test this is how. Take the aire boot off the TB. Then with NO fuel flow at all spray the nitrous system for 10 seconds. You should see 1.2 lbs. of nitrous loss. Now this is asuming you have no 90' fittings in your install on the nitrous side.
Care should be taken during this test, that NO fuel is able to flow(fire hazard) and that the nitrous discharge is not aimed at anything valuable or a person.(it will be extremely cold coming out) so be careful. If you would like a better explaination on this call me. 888-463-2781.
Hp is down because you are way rich, now we have to find out why are we rich.

Ricky

SDB

iTrader: (7)

no 90 degree fittings at all, just what cme in teh kit. I will also check my nitrous filter (put a brand new one on with the kit, a NOS big-blue replacable filter). I thought this might be the next step....have done it on an older system. I will try this tonight if I get a chance. I have a complete refill station with digital scale, so it shouldn't be too hard. So the 62 jet in the single nozzle should deplete about 1.2 lbs per 10 seconds? It is weird that the kit was SOO rich on the stock jetting, it was 9-1 AF ratio with teh stock 150 jets. We got it down to 11.5 AF ratio with the 31 fuel jet. The weird thing is that on the 100 shot, it didn't feel as rich as the 150 shot (didn't pop or have any fuel backfire, BUT I never tried monitoring it or tuning it with 100 shot).

If the flow rate is correct, what else are you thinking for the rich condition?

Thanks for the assitance.

SDB

NXRICKY

iTrader: (1)

Correct.

Maybe the sucktion on the maf is thoughing things off, but that is just a guess. If flow matches what it is suppose to then its something with the car,
Not neccessarly bad we just need to tweak the tune up. We just want to make sure the car is happy, and not a fluk going rich, then you dial it in, and then BAMMMM the car is back to the old way it should have been, and you go way lean.
LEt me know on the flow test.
Ricky

SDB

iTrader: (7)

will do! I never thought of hte MAF being a problem since the nozzle is after it, but it does control a lot of parameters (even auto shifting on the 04 GTO's believe it or not). I wonder if the walboro intank fuel pump 340gsm/255 lph pump is causing a little more pressure than normal to push through the regulator...I was getting 60-62 psi on the rail after the pump install. I noticed on my Camaro the pressure went from 56-60 after the pump install. That could be enough to fatten up the car I guess.

SDB

Robert56

iTrader: (2)

I think Ricky gave some right on input. On KR, getting this before and after n2o is something pointing to non n2o. sometimes it's as simple as a header tube or exhaust hitting slightly, or overly sensitive sensor, or to much timing for your set-up period. I agree with V6 Bird get that taken care of then address any n2o issue.

SDB

iTrader: (7)

OK....I plugged in an extra FPSS into the line coming from the fuel rail to stop up the fuel flow before the noid (works good). I made a jumper wire to put across the two poles on the actual FPSS I have installed on my car. I took of the elbow where I have the nozzle mounted (2 1/2 inches from beginning of TB). THe GTO has a 90 degree elbow, and not any room to put the nozzle back any further unfortunately). I removed the bottle, weighed it (it was real low, so I blew it down and put about 10 lbs of fresh N20 in it). I hooked it back up, opened the valve, turned on the heater (and battery charger), played with the timing tuner to get it to activate at 2000 rpm. after a while, got the pressure to 1050. Sat in the seat and hit the bottle for a second (actually did this 3-4 times, it only worked for the initial fraction of a second then went off, thats when I realized I had to start the car and actually get the rpm's to 2000 rpm for it to work right). I sprayed for 8 solid seconds, and figures I used about 2 seconds total from playing with it before. I started with 30 lbs 6 oz, and when I re-weighed I was at 28 lbs 11.25 oz. So, I used over the 1.2 lbs previously specified, so I am pretty sure the flow rate is OK and that I have no restrictions. 1 lb 5.25 oz. was used (1.328 lbs), so your 1.2 lbs is real close! This was through the nozzle and 62 N20 jet.

On a separate note, I tried the rpm window switch set at 2750 instead of 3000, and it worked very well. Is this too low for a 150 shot on an automatic GTO with stock converter. The reason I set it a little lower is because it is an absolute dog until it got to 3000 rpm with the stock converter. I used it 4-5 times at 2750 with no ill effects. Is this unwise or not?

I will try taking more timing out with the timing tuner and monitor with EFI LIVe to see if it works out, and if so I will have it retuned with a little less timing and look at desensitisizing the knock sensors.

Any other things to check out Ricky?

Thanks

SDB

Airwolf

iTrader: (2)

Question... Aren't the jet tables for the LS1 meant for 56-58 PSI, not 62 PSI? Would this not cause a richer condition at the higher fuel pressure. Using a smaller jet would compensate for this higher fuel pressure. Just a thought... One last question, what is your A/F ratio off the juice? I don't think I saw that.

SDB

iTrader: (7)

Yes, I thought the same thing, maybe the little extra pressure could account for the "fat" condition.

I played with the timing tuner tonight and got rid of KR on motor and bottle. I took out 2 degrees at WOT (above 3000 rpm) and another 2 degrees out across the board on the motor. On the nitrous, I took an additional 4 degrees on the nitrous. I need to get this back in for tuning, and have him take out some timing!!! I only get a little KR on the nitrous now (about 1 degree in 3rd gear, not all the time). Car pulls more smoothly now.

I still may lean it out with a 29 or 30 fuel jet when I put it back on the dyno to try for 12.0 to 12.5 AF Ratio on the bottle.

NXRICKY

iTrader: (1)

Ok looks good hear, the 8 second burn would have liked to see 10 but we're are close.
Things to check on while you have the EFI live hooked up.
Read your air temps coming into the engine. Not sure about placement but if the nitrous is even coming close to the sensor it will show a cold air and start dumping more fuel..
Another thing is the MAF signal need to make sure it is not doing anything stupid.
As far as the fuel pressure, not enough increase to throw the jetting off that far. WE are talking about, less than a .5 on nitrous to fuel ratio.
Now the final out come maybe we must tweak the tune up on your car to get the a/f right and sweet. But let make sure all other parameters will not change later in life.
Ricky

SDB

iTrader: (7)

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I did a 8 secnd burn and a couple of shor burns, I figured it totalled around 10 seconds or so.

Air temps are not affected by my nozzle...the IAT waaaay down on the long part of the "elbow" of the air intake tube (by the MAF). Air temps are consistently 95-115 degrees, depending on how long I sat and idled. Not different during the nitrous or motor runs when checking the file.

I didn't notice any weird readings on MAF, but don't really know how to monitor that sensor all that well. If I choose to try to lean out the fuel jet, what size do you recommend. I have a consistent across the board AF ration of 11.5 on the bottle with the 31 fuel jet (down from the 33 or 35 stock 150 shot jet), and the 62 nitrous jet. I have a 28 jet, but that seems a little drastic, I was thinking like a 29 or 30.

V6 Bird

iTrader: (15)

You are playing with fire if you like 12.5:1 on the bottle! It wont hurt anything but torque will be lame vs 11.5:1....I usually shoot for 11.2:1 on the EFI cars. Hyperjunk pistons dont like heat

Mike

NXRICKY

iTrader: (1)

Since nothing weard I wuold got ahwad and do a 30 then29 then 28 until the car cleans out.

Ricky

SDB

iTrader: (7)

Well, I am thinking I may try a 28 one time on the chassis dyno, going there soon...probably will remain at the 31 for safety sake. I am glad I got the timing issue/KR figured out....feels a little better now especially in top of 3rd.