Nitrous Altitude Adjustment

[Craig W.]

Just click the key back one notch. It'll kill the motor, but won't lock the column.

[Mike Peters]

OK, so shifting into neutral at the top end is bad, even going from 3 to neutral (I don't have the reverse pattern)? Didn't know that. I don't have a ignition kill switch (just the key switch which has the column lock, definitly not good). So I will have to coast down with the engine running and stop on the return road (if I can). Sound good?

Going to LACR Saturday, everything's falling into place so far!
As always, thanks guys!
Ken

No Ken, you definitely don't want to lock your steering column while you're still moving. Might want to think about installing a kill switch in the circut sometime so you can do the afore-mentioned shut-down procedure to get the best plug readings.

[julven]

I don't know if you have been into very many columns but the lock plate can be removed. We have done it a few times on nova/camaro columns. Jason

[71 Nova]

Here's my results from Saturday's excursion to LACR. Note that LACR is at 2710 ft above MSL and the times I will report are corrected to sea level per the NHRA correction factors (0.97 for ET / 1.03 for MPH):

On this day, LACR was running the Jr. dragsters and they were catering to them. We (the cars) were in the minority by a lot and we did not get many runs in, about 1 every 1 1/2 hours (I got 4 runs in). It was a warm day, high 70's, breezy and 20-25% RH.

(11:25, 72 degF) 1st run: I ran the car NA to get a feel for the car and the track. The car bogged off the line (ran a 2.2 sec 60 ft., ugh) but ran well after that. I didn't launch with enough RPMs (around 1000 RPM) plus the car was running rich from the altitude (10.7-11 AFR). Still, I ran a 13.69 at 100.94 MPH.

(12:45, 76 degF) For the second run (NA), I readjusted the idle mixture screws to lean out the mixture and bumped the engine up to 1600 RPM at launch. The car launched good at 1600 RPM, with a 60 ft time of 2.09 sec and a ¼ mile time of 13.62 sec at 100.42 MPH (10.7-11.5 AFR).

(13:51, 77 degF) 3rd run was again NA, had a good launch and I ran a better 13.54 sec at 100.46 MPH (no 60 ft. time). OK, now I'm ready to crack open the bottle ...

(16:35, 77 degF) 4th run: I swapped in a new set of NGK nitrous plugs and opened the bottle, but by now (4:30 pm) a wind had kicked up perpendicular to the track. Right next to LACR is a mining operation and they had mounds of dirt right next to the return road (which is right next to the track), just upwind of the track. Anyway I did a good burnout to get the tires plenty hot, armed the nitrous and staged. At the green light, I mashed the throttle and the car jumped off the line, then the nitrous hit and we were going places. I shifted at 5500 RPM, but after the 1-2 shift, the tires broke loose and the car started sliding sideways, heading toward the centerline. I tried to correct but had to let off. I straightened out the car and hit the throttle again, but went sideways again when the nitrous hit. I gave up after that and coasted to a 13.54 at 79 MPH. The track was way too loose. In fact, they closed down the track for the day after this run. Track pictures here: http://www.lacr.net/lacrpics.html

To put the run into perspective, I was racing against a 67 Charger with a nicely built 440 (11 sec car), and I was ahead of him at 330 ft by 0.3 sec and stayed ahead of him until about half track (I ran an 7.82 sec 1/8 mile @ 82 MPH vs. his 7.83 sec at 91 MPH). He ended up running a 12.10 at 115 MPH that run, so I was probably on track for an 11 second 115 MPH run until I lost traction...

There's a picture of my launch here (at the bottom): http://www.photoreflect.com/pr3/ThumbPa ... 7898&s=210

All in all, I am very pleased with the cars performance, in reality it was a blast! I think I coulda ran 11's with a good track, but such is life. I need to investigate why the car pulled/slid to the left when I lost traction on the nitrous run, but other than that, the car ran fine. It's been many years since I've been to the drag strip (to race); I'd forgotten how much fun it is! Next trip is to Bakersfield (Famoso) in early May. Thanks to all for all your help!
Ken

[mytmouz]

[John_Heard]

Did you get a chance to pull a plug and look at it?

[71 Nova]

Yes I did. I wasn't at full throttle very long (about 5 sec.) so the plugs didn't color too well. Looks like I'm running rich (confirmed by data indicating 10.5-10.7 AFR). Also the heat mark on the ground strap is about 1/2 way from the end to the bend. I don't think that I can rely on these since I didn't run too long and drove back to the pits before pulling the plugs. Pics attached...

[Racer704]

Was 10.7 AFR the leanest at the end of the run? If so and you lifted I wouldnt try to lean it out with the nitrous on without making a full pass.

[John_Heard]

They certainly don't look fat, and really didn't color much at all on the return road. Just a bit starting to show on the porcelain. Very clean on the plug base. You can see that the plating is just starting to burn off in those pics, they really didn't see much heat, or for very long.

Did you wash these plugs off with anything? Brake Cleaner? If you didn't as JB said, don't take fuel out, if anything I'd be tempted to put a bit more fuel in it before your next trip out.

[71 Nova]

Racer704: The 10.7 was the AFR during the 1st part of the run, before I lifted (up thru the 1-2 shift). The AFR and RPM were all over the map after I started sliding.

Beyond: I did not clean the plugs at all. I was only at full throttle for a relativly short time. I'll up the fuel pressure a few tenths before my next run.

Thanks guys.

[Racer704]

I would put no less then 1/2 pound of fuel. Tell me what AFR your looking for at the finiosh line with N2O?

What nitrous system and style are you running and what jets and fuel pressure you run also whats your bottle pressure at launch?What brand fuel are you running?

[71 Nova]

Tell me what AFR your looking for at the finish line with N2O? I have been looking for 10.5 AFR on nitrous. Does that sound correct?

What nitrous system and style are you running? NX Hitman Plus carb plate system http://www.nitrousexpress.com/Pages/Hol ... anPlus.htm

What jets and fuel pressure you run? 150 HP jets (XX” fuel, YY” N2O, I’ll post the sizes later tonite), 8.1 psi FFP, 12.4 psi static pressure just downstream of the reg. 6 degrees of timing pulled out when nitrous is armed.

Whats your bottle pressure at launch? 1000 psi, run was with a full bottle. I have a pressure controlled bottle heater that controls bottle pressure to 1000-1050 psi.

What brand fuel are you running? 91 pump gas (engine is 8:5-1 compression)

[Mike Peters]

Nothing wrong with leaving it in gear with the motor running or not. But don't downshift it till you get slowed down like when you're coming back down the return road.

Now, I read this from another well-known forum in the transmission section - NEVER SHUT OFF THE ENGINE?>>>>>>>>

I will go out on a limb here & still suggest that clicking an engine after neutraling is VERY BAD. Even with the safe neutral(which I also offer in my turbo400s - W/Griner valve bodies) The whole idea w/safe neutral is to take the decceleration load off the engine, but shutting off the engine is still a very bad idea. This sends the transmission into the same circumstances that cause catastrophic failures to 3-speeds. The direct drum is accelerated to an overspeed that can cause explosions w/cast drums & clutch damage w/aluminum drums due to centrifugal apply. The same can be said for glides, only on a smaller scale. I will always tell my guys to ride it out in high gear or neutral w/safe neutral designs & NEVER shut off the engine.

Have a nice day
__________________
What do ya say,What do ya know ?

Dave Klaput (F. RIZZO)
Proformance Racing Transmissions

[hsutton]

Nothing wrong with leaving it in gear with the motor running or not. But don't downshift it till you get slowed down like when you're coming back down the return road.

Now, I read this from another well-known forum in the transmission section - NEVER SHUT OFF THE ENGINE?>>>>>>>>

I will go out on a limb here & still suggest that clicking an engine after neutraling is VERY BAD. Even with the safe neutral(which I also offer in my turbo400s - W/Griner valve bodies) The whole idea w/safe neutral is to take the decceleration load off the engine, but shutting off the engine is still a very bad idea. This sends the transmission into the same circumstances that cause catastrophic failures to 3-speeds. The direct drum is accelerated to an overspeed that can cause explosions w/cast drums & clutch damage w/aluminum drums due to centrifugal apply. The same can be said for glides, only on a smaller scale. I will always tell my guys to ride it out in high gear or neutral w/safe neutral designs & NEVER shut off the engine.

Have a nice day
__________________
What do ya say,What do ya know ?

Dave Klaput (F. RIZZO)
Proformance Racing Transmissions

A friend of mine's wife put a Chevette on it's top by pushing the powerglide into neutral just before the finish line and got reverse instead. Went thru the lights at 120 MPH upside down. Roll cage, belts and God saved her injury but it did scare the hell out of her. He said the transmission company said the tranny had a reverse lockout and what happened was impossible, however they weren't in the car!