DIGGLER

iTrader: (1)

too much pressure. set it up for 900 and call it a day. might want to doublecheck your pressure gauge as well. it may have been higher than you thought.

five7kid

iTrader: (14)

I put my in-line gauge adapter with a cap on the old bottle with its own gauge to check them against each other. The new in-line gauge read about 50 psi lower than the old one. So, since the new gauge is all I was reading yesterday, it is very possible that the pressure was even higher than what I saw.

Of course, which gauge do you believe? They are both the same brand from the same source, just purchased 4 years apart. I suppose I could ask the track if they could compare mine to theirs when they fill the bottle next (assuming their gauge is calibrated).

900 psi

900 psi

900 psi

900 psi

(Maybe if I repeat it enough, I'll remember it next time...)

mw66nova

iTrader: (13)

i know, it's really easy for me to sit back and spend your money Tim, but take a look at this gauge:

http://inductionsolutions.com/shop/b...with-fittings/

if you look through that site, you'll find "Steve's two cents" and in a couple articles he mentions something about size and quality of the gauges used...i believe this guy to be the modern day authority on nitrous after reading and hearing his stuff and comparing it to others info. his info seems to be the most consistent all across the board.

having not used nitrous yet myself, please take this all with a grain of salt...but i do have a kit now, and plan to flog the heck out of this things once i get a job again.

five7kid

iTrader: (14)

Spending other people's money is fun. I do it all the time.

five7kid

iTrader: (14)

But, I had to spend my own money to order the gauge...

mw66nova

iTrader: (13)

DIGGLER

iTrader: (1)

i would figger the pressure was more like 12-1300psi for the noid to be disabled. i have witnessed 1300psi making one not work. not mine, but a fellow i was with got stuck in staging for awhile. bottle baking in the sun in the hatchback the whole time.

five7kid

iTrader: (14)

Well, it wasn't totally disabled (although the purge solenoid was for the first pass), just delayed opening relative to the fuel solenoid. Since the delay was the worst for the first pass, and lessened a little after that, excessive pressure does make sense.

The bottle was freshly filled at the track Friday evening. Saturday morning when I mounted it for the first time, the pressure read about 850. I had the car oriented so the sun could shine on it with the door open for about an hour, then it was just in the car with the hatch and windows open, no direct sunlight. I did put a wet towel over the bottle when I saw 1100 psi before the first pass, but I have to admit I didn't have a straight-on view of the gauge, so it may have been reading higher. And, I already know that this gauge reads lower than the one on the other bottle, so it could have been more like 1200-1300.

While this bottle was in the car, the other bottle, which was filled in 2010, read 900 when I first got out to the track. I put it in the sun at first, then moved it to the shade when the gauge got up to 1000. It sat around 950-1000 for the rest of the day, which I assumed would mimic what the bottle in the car would see, as neither was in direct sun after that. So, I was surprised to see 1100 when I opened the bottle for the 2nd run. But, the air temp did get warmer as the day went on, and I didn't put a wet towel on it after the first pass, either, so...

midias

Tim Larson?

five7kid

iTrader: (14)

Present.

midias

Awesome car great runs.

five7kid

iTrader: (14)

Well, that car hasn't been running for over 3 years. The engine that's going in it wouldn't need nitrous to run the required number. But, I haven't gotten it running in time for this season. Hence, the Camaro getting sprayed.

brandoz28

iTrader: (1)

i would say its a pressure problem. try it at closer to 900psi and see how it goes

five7kid

iTrader: (14)

Yes, it all makes sense now. The evidence was right in front of me, but I didn't figure it out in time.

The purge solenoid should have been my first clue. But, the NOS solenoid is much larger than the Edelbrock solenoid, so I blamed Edelbrock (and, it's a 4-year-old part).

This coming Friday I'll have 4 shots at the track before eliminations (weather permitting). I may go ahead and use that opportunity to give it another try. Not on all 4, of course. (Yeah, right...)

five7kid

iTrader: (14)

The gauge was shipped Monday, left Florida yesterday, and is estimated for delivery Friday. Oh, well. If it gets here before I leave for the track, we'll see...

Dakota W.

Take video sometime. In car, preferably.

five7kid

iTrader: (14)

Two issues there:
1) I don't have a GoPro.
2) I don't have a roll bar to attach a GoPro to.

But, I may try to rig up something anyway.

In looking over the race schedule, Super Chevy is next weekend. Non-points race, and I'll only be there on Friday (they have an LS "race-within-a-race", which I happened to win last year). I'll probably use that date as a try-it-again date. The next race that I need the nitrous again is the following weekend (both Saturday and Sunday this time).

mw66nova

iTrader: (13)

suction cup mount to the inside of the passenger window seems to work pretty well

five7kid

iTrader: (14)

All I have available is a Kodak SLR digital camera. It would take a pretty hefty suction mount to hold that on.

mw66nova

iTrader: (13)

lol, true. just throwing it out there. hey, what about a mount off the passenger side seat studs? (lol, it worked in the last mounting problem you had).

Joe Tag

iTrader: (4)

I know you wanted to get away from comments on your race vid. I watched the whole thing and just had to say how cool it was that Bigbey won it all after the controversial run. The fact that his opponent stood tall and admitted defeat gives me just a little more faith in humanity.
Again, sorry, back on topic.

five7kid

iTrader: (14)

We were behind the tower after going out and he was mumbling that he was sure he crossed first, so I asked him if they said he went too fast. He said, no, they didn't say anything. So I said, go tell them you think you won. He hesitated, so I said go ahead, they'll take a look at the tape if you challenge the loss. So, he went to the start line, and you saw the rest.

What caused all that was a cameraman stepped into the staging beams in the right lane as the cars were pulling forward, then stepped out. The system got confused, so when they both finally staged, it wasn't ready.

I didn't know either one of them very well before that, but since then have come to the conclusion that they're both standup guys. Yes, it does restore some faith in humanity (especially considering the madhouse going on around there).

five7kid

iTrader: (14)

Tonight was a test & tune, and my wife had someplace to be, so I decided to see what I could figure out. I considered using the time to install the bottle heater, but decided to take my chances at the track without it.

First thing I did was assemble the new gauge. I took the same bottle out to the track as I had used last time. I also used the bigger tires, because traction isn't known to be great on these test nights.

The bottle had been in the garage, and it's been cool for several days, so it wasn't very warm. The sun had already gone behind the hills by the time I got to the track, so I couldn't use it to warm the bottle any. 1st pass, it was dead on 900 psi after getting liquid out of the purge line. Staged, hit it - on its nose again. 0.162 RT. Ran a 12.03.

I looked over things in the pits, wondered about voltage, checked the solenoid ground (same for all 3 solenoids). It was a little shaky, so I cleaned everything up, put the terminal against the firewall itself, looked a lot better than before. About all I could do to warm the bottle was get a towel as warm as possible against the engine and put the towel on the bottle, and run the car heater on high.

2nd pass, pressure was about 880, it stumbled again, but not quite as bad. However, the track wasn't very good (way too much water beyond the water box), and the tires didn't get a complete bite. The run was a tad slower, 12.07, but RT was at least in the .09's again.

Now I'm wondering if it's just too rich. I pulled a plug (not new plugs, and I drove back to the pits - not the way you're supposed to do it, I know). The plug was for sure not lean, so, I went from a .026 fuel jet to .024. Bottle pressure was down to 860, but this time it didn't stumble a bit, had a .008 RT, and best pass of the evening so far, 11.99. I also purged a little longer and got a better stream of liquid than before.

Bottle pressure was down to about 840 at the end of the run, so I took the bottle out of the brackets and set it in the engine compartment until I had to get back into the staging lanes before they closed them for the night. Pulled a plug again, looked about the same. Bottle pressure was only about 850 as I pulled into the water, after the burnout I hit the purge, and got nothing but gas. Kept trying, the other guy was already staged, nothing but gas, bottle pressure was down below 800, so I disarmed the system, staged, and made a NA pass. Went a little red (I knew I left early), ran a 12.92.

So, I don't really know at this point if the smaller fuel jet was the key, or if the bottle pressure being down allowed the solenoid to work as it is supposed to. I'm leaning toward the fuel jetting.

When I need it again next weekend, I'm thinking about putting in 100 jets, not turning the system on and leaving NA, then hitting the system at half track (just after shifting to 3rd) or 1000'. That should be more than enough to get below the 12.75 qualifying/max-dial-in ET. A 2nd gear switch would be nice, but I haven't looked it to what that would require (and for sure don't want to sink more hundreds of $'s into this).

Oh, it appears the gauge I was using back on the 3rd was reading about 60 psi low, compared to this new gauge, and about the same lower than the gauge I have on the other bottle.

And, I can get 6 passes out of a fill with a 75 shot without a bottle heater...

mw66nova

iTrader: (13)

sounds like some good data!

five7kid

iTrader: (14)

Or, maybe I just haven't purged properly...

I see RPM switches from Summit and Jegs in the $50 range. Maybe that would do it. Get off the line, then let the switch bring on the nitrous. Probably more repeatable than I could be manually activating the system.

NOS has one with two triggers, plus a high RPM cut off. I'd only use the RPM trigger, but the top cut-off would be a safer system than the LS PCM upper rev limiter (cuts off fuel, not ignition). But, that's 3x the cost.

mw66nova

iTrader: (13)

what if you did a timer based controller triggered off the brake light switch?

oh, not sure how much you use it, but i sent you an add request on facebook

five7kid

iTrader: (14)

A timer would also work. But, they start in the $150 range.

Now that I'm more awake, I see Jegs has an RPM switch with both activation and deactivation RPMs for around $50. I kind of like that.

(As of last week, I'm not using FB anymore. But, I'm not using it any less, either... )

mw66nova

iTrader: (13)

lol, it seems to be easier to use than the boards now-a-days for some reason. just much more fast paced and real-world-timed i guess. i'll send you a link to my group on there, "****** Militia". it's got a lot of the heavy hitters from here on it, and i'm getting a pretty solid group of tech savvy guys together on there.

five7kid

iTrader: (14)

This is probably a long shot, but looking back over the NOS instructions:

Do's:
"Use your NOS nitrous system only at wide-open throttle and at engine speeds above 3000 RPM." (probably more of a safety thing than optimal operation thing)

Don'ts:
"Allow nitrous pressure to exceed 1100 psi. Excessive pressure can cause swelling or in extreme cases failure of the nitrous solenoid plunger. Solenoid plungers are designed so that pressure-induced failures will prevent the valve from operating. No leakage should occur with this type of failure."

Guess I'd better take a look at the nitrous solenoid plunger.

I have the 2-step set at 2900. It randomly cuts out ignition to the cylinders, which will leave a rich condition. Adding the nitrous immediately as it is coming off the 2-step may be more than the poor engine can handle.

If, however, the nitrous is delayed until, say 4000 RPMs, the engine will have had a chance to "clean up", and won't be as affected when the nitrous system hits.

I was also wondering if it would do better with a bigger shot. Delay to higher RPMs, bigger hit...

DIGGLER

iTrader: (1)

im gonna say its way rich if its bogging like that. i would fix that before swapping to bigger jetting. sounds like your jet change helped a little bit. you can try taking fuel away a small step at a time while watching your trap speed. you have a good enough grasp on that to where you should be able to nail down your tune easily. once you figure it out for this hp jetting, use the same jet spread for the next larger shot. dont forget to pull more timing.

on the plunger not opening thing, if you can imagine standing in the bathroom and sticking a plunger on the floor. trying to pull it back off is difficult, but do-able. now if you pressurized the bathroom with 25psi, you may not be able to get it off the floor anymore. thats kinda how the nitrous solenoid works, the pressure is on the back side of the plunger, and when it opens it is pulling the plunger off the floor, revealing a hole which leads to the nitrous jet.

91_B4C_RS

This is the timer I use off of the transbrake. Maybe you can trigger it off if brake switch??

https://www.dynotunenitrous.com/stor...?idproduct=107

five7kid

iTrader: (14)

I completely understand the effect of bottle pressure on the plunger. At work I've investigated a lot solenoid valve failures in systems up to 4000 psi with helium - believe me, doing that reliably ain't easy. I just wasn't thinking about it that first time at the track, probably because the NOS solenoids were so much bigger than the Edelbrock solenoids, it didn't cross my mind that bottle pressure could be a problem.

But, I think it's more than that. Coming off the 2-step and hitting the nitrous at the same time would seem to be causing mixture issues. So, delaying the nitrous will probably clear it up.

I could trigger that off the 2-step switch in the brake pedal. But, the RPM switch should be as good (and if engine RPM at time of nitrous activation is the issue, should be better - or at least easier to set up - than a timed switch). I talked to the owner of a '99 Vette at the track this weekend, and he also couldn't get it to launch correctly activating the nitrous at the hit, but the RPM switch cleared it all up.

And, the RPM switch was just delivered to the house...

five7kid

iTrader: (14)

Got the RPM switch installed the last couple of evenings. I mounted it on the vertical portion of the dash, to the right and under the center vents (just to the right of the console - easy to reach, but shouldn't be easy to bump). It works by providing a ground, so I ran the solenoid activation relay ground to it. 3A max, so the relay shouldn't give it any fits. The first try I had a bad ground, but it was almost midnight, so I called it quits. Last evening I tried again, and seem to have a good ground now.

I tried to do a solenoid activation test last night with just the fuel available (no nitrous bottle installed), but it had been raining all evening, so if the engine bogged when the fuel solenoid opened, the spinning tires didn't care (and I was already in 2nd gear).

We have a points race this evening, but I won't be running the nitrous for it. It's dry now, so I may be able to do this "test" on the way to the track. I was able to determine a couple of things: 1) The display is very bright at night (but at least the red digits match the red Dakota Digital VHX instrument panel); and 2) when it activates, a blue light comes on in the top of the box. The box isn't directly in my line of sight, but I was able to see the blue light out of the corner of my eye last night (may be a different story in daylight).

Also, although the display has 4 digits, and is supposed to be able to function as a tachometer, it rounds RPMs to hundreds. So, 870 RPMs on the tach digital readout is 0900 on the RPM switch, 630 is 0600, etc. Not a biggie, but to call it a "tachometer" is a misnomer.

Now that I think about it, with the blue light I should be able to check the "shut off" upper RPM function on the way to the track as well to see if RPMs have to drop below the "on" RPMs to turn it back on after shutting off at the high RPM set point.

five7kid

iTrader: (14)

Well, like I said, I didn't want to do it, and I'm even more convinced now...

Saturday, 2 time trials in the form of qualification runs. Had to run 12.75 or quicker at least once. I had confirmed the RPM switch would at least turn on the fuel solenoid, and that once it hit the high RPM cut off it wouldn't re-arm until RPMs dropped below the trigger point. I had the bottle pressure where it should be, purged to a good liquid flow, staged like I normally do, took off and cut an acceptable light, and the nitrous comes on. I was so impressed that I forgot the 1-2 shift - banged the RPM switch cut off and hit the PCM rev limiter before I got my head about me. Of course, the nitrous didn't come back on, and my timeslip showed a 13.17 - not good enough.

For the 2nd try, I decided to let the computer do the shifting. Since I normally shift it myself, I needed to adjust the shift RPMs a little (which I had just figured out how to do in HP tuners). After flashing the new values, they called us back into the lanes. Bottle pressure good (between 900-950), good purge, staged, take off (a little red - .002). It was then I realized I had shifted down to first like I normally do, managed to shift before it was too late, it did the 2-3 shift fine - but the guy in the other lane seemed to be walking away from me a lot more than he should be. Got the timeslip, 13.01. Now what? As I started back down the return road, I looked over at the RPM switch as if it hadn't done its job, and realized the red LED on the nitrous arm switch wasn't on - I hadn't turned on the nitrous switch! So, I DNQ'd for the day. Dropped from a tie for 8th place down to 17th place.

Sunday, the King Street class is running again, along with a "specialty" foot brake race. I enter the foot brake just to get a couple more shots at the track. The bottle pressure was low in the morning, so I left it in the sun and went to the RFC chapel service. That lasted longer than I expected, when I got back to the pits, bottle pressure was up to 1100 psi. So, I shaded it, sprayed it, and put a wet towel over it. They had already called the footbrake class into the lanes, by the time I got the pressure down down to 950 psi, I was at the end of a long line. When I finally roll down, I made sure I was doing everything that needed to be done (including turning on the nitrous switch), and when I was the next into the waterbox, turned on the nitrous valve. A few seconds later I see a stream coming out of the purge line. I hit the button a couple of times, the flow increased with the purge solenoid activated - great, the solenoid is leaking. I turn the bottle valve off, do the burnout, turn it back on as I roll to the start line, and it's putting out a small but steady stream from the purge. Stage, make sure the shifter is in 3rd, take off (acceptable light), nitrous comes on at 3900 RPMs like it's supposed to, 1-2 shift is fine, 2-3 shift is fine, cross the finish line and turn off the nitrous bottle (still had a stream coming out the purge line). Get the time slip, 12.05. Decent.

But, that didn't count as a qualifying pass for this King Street class that I'm doing all this for. That was called next, before I had much time to cool off the car. Bottle pressure still okay, go through the same routine, when I turn on the nitrous bottle, the flow out of the purge is bigger now. Stage, take off, okay light, nitrous comes on, shifts fine, 12.18 on the time slip. Okay, pretty significant drop off, but at least this time I'm qualified.

There were several other classes that then had their time trials, so I hopped in the truck and ran home to get another Edelbrock nitrous solenoid to put in the purge position. I had two - a loose one, and one still tied to the fuel solenoid. I decide to take the fittings out of the 2nd one before heading back to the track, and the inlet fitting breaks off in the solenoid - great, down to one. I get back to the track, while changing it out they call the footbrake class back to the lanes. I'm stuck at the back of the staging lanes again. The solenoid needed a few love taps to start working reliably. Bottle pressure still good, make the pass, runs a 12.27. Again slowed more than the weather should have slowed it down, but seemed to run okay. By the time I make my run, they've called King Street back to the lanes. I take my time cooling the car down, bottle pressure still okay, make the pass, 12.38. Okay, that's really slow. I had gotten 6 full passes out of the bottle the first time out, I've only made 4 plus one gear on this one, but the extra purge flow probably drained it off quicker. I switch to a fresh bottle - sure enough, the bottle was empty (I went ahead and had the track refill it). But, with a full bottle now, I will have to guess at a dial-in for the first round. .

Footbrake first round the other guy is slower, I put a 12.3 on the windows, he cuts a poor light, mine was acceptable, pass him before 1000', stay in it past 1000' foot for the data, back off to an easy win. Using the first two passes as a baseline, both indicate it would have run a 12.25.

They call us in for King Street, I find out who I'm paired with, the wind has come up a bit so I put a 12.28 on the windows. He's dialed 10.46 so I go first. And, I go -.011 red. Run it out to a 12.297. Done for the day in King Street.

I go back to the pits and take out the nitrous bottle. Weather station says I'll run a 12.96 under the current weather conditions, so I put that on the window. I considered a 12.97, but the wind died down compared to what I had entered in the ET predict, so I left the 12.96 on. I'm slower again, I take off and pull a -.005 red light. Run it out to a 12.978 - not too shabby considering I hadn't made an NA run all day.

Oh, yeah, forgot to mention - every time the nitrous came on, the engine bogged, then took off. But, at least with the RPM switch, it didn't affect RT anymore...

So, that's that. The next King Street race is September 29. The weather should be cool enough by then that it'll run a 12.75 on its own (may take some weight out again). In the meantime, next weekend we have a big 3-day end-of-summer season race, with the last remaining points race for the summer series on Sunday (jackpot races on Friday and Saturday). The nitrous will NOT be at the track with me next weekend. And, I'll be going to the Division V ET Finals in Topeka two weeks after that, and FOR SURE it won't be used there...

mw66nova

iTrader: (13)

Bracket racing with nitrous seems to be a real pain. A cam swap and tune would have been easier and cheaper I think.

five7kid

iTrader: (14)

Easier to do, no. Easier to race, most likely.

My LS6 valve springs most likely would have dictated a spring swap with any cam swap that would guarantee the number. Cams typically start at $350. A reliable tune would have been $400-$500. That's a grand without sneezing. And the time - much, much longer to do a cam swap.

At Super Chevy a weekend before, I was pitted next to a local racer with a '99 'Bird. Except for a head gasket late last year, he's never had the heads off. MS4 cam, LS6 intake, valve springs, headers, TH350 with a bunch of stall, 9" rear, 6-point, mail order tune from TSP, he runs 11.8's up here. But, he trailers it to the track. So, yes, I understand the potential of what would traditionally be called "bolt-ons" with these engines.

five7kid

iTrader: (14)

FWIW, I ran this class back in '09 with the '57, which required a shot just to get it below 12.75 in any weather. I missed one race that year because somebody wasn't thinking and scheduled a race in that series the same weekend as the Summit Div V ET Finals, which were in Topeka that year. I ended up in 6th place in the season points, even missing a race. Oh, even DNQ'd once that season as well when a poor electrical connection kept the nitrous from staying on for both qualification passes. So, it's not like it can't be done.

On the other hand, last Friday evening, I made it to the finals in another class I'm running, without nitrous.

Without a doubt, adding nitrous to the mix gives you one more thing (or several more things) to think about as you are rolling down, distracting you from your routine. Unless, of course, you run it all the time, and especially if you also have a crew to roll down with you to take care of some of those details.

mw66nova

iTrader: (13)

agreed. wasn't saying it can't be done, or too hard to be competitive with, just know that there are lots of extra variables.