[twooldgoats]

Went out to make some TNT passes at SIR with the new simplified tune. The first pass was a 9.41 @ 143. WTF!!!!!! I did get some EGT data on the pass, though, and noticed an oddity: neither cylinder #2 nor cylinder #3 got above about 100 degrees. I wasn't sure, of course, if it was a problem with the EGT senders or a real problem. When I pulled the plugs, neither one of them looked like they had fired. I rechecked the resistance of the two plug wires. They were both OK. Then, I called my engine guy, Paul Carter, and he suggested checking them with a timing light to make sure they were both firing. They were. Hmmmmm...... What if the cam manufacturer screwed up and my 2-3, 4-7 swap cam was really just a 4-7 swap cam? I switched the #2 and #3 spark plug wires and fired it up. It definitely sounded crisper.

So, I made a pass: 8.287 @ 167.88 mph. That's more like it. We leaned it out just a little more and went 8.254 @ 166.07. Not sure what happened with the mph there. The ET was a little better, but the mph slowed, even though I was 133.01 mph @ the eighth mile on that last pass, compared to 129.64 on the other good pass.

As it turned out, my 9-second passes the last two times out were on six cylinders! I'm still having a ton of trouble getting good EGT data, but what I was able to get showed no cylinders over 1,000 degrees. I may not be getting full pass data, though.
I sure wish now I had just skipped the Red Alert system and added EGT sensors to my Racepak. The Racepak seems to be working fine.

So, I've gotten a lot closer to my goal of a seven second pass. There's a lot of tuning left to do and I'm under-driving the blower 10%. The density altitude was over 5,000' for my 8.25 pass. The car ran absolutely straight and felt great. My 60-foots, 1.279 & 1.259, have a long ways to go, but I'll worry about that later.

Jim

[gtofreek]

That's great Jim! I need to look up the info on that cam to see what happened there. It was supposed to be a 4-7,2-3 swap. That's what I remember anyway.

[GOAT WHORE]

Nice work on figuring out the cam deal Jim. Pretty fast 6cyl

[Tom Vaught]

Getting it squared away. Looking forward to a post with a 7 second time slip in the near future.

Tom V.

[twooldgoats]

Originally Posted by Tom Vaught

.... Looking forward to a post with a 7 second time slip in the near future.

Tom V.

Me too. You can be sure I'll post it when (if) I get it. The seven-second time slip has been my most tangible goal during this whole blower conversion deal.

Jim

[gtofreek]

Originally Posted by twooldgoats

Me too. You can be sure I'll post it when (if) I get it. The seven-second time slip has been my most tangible goal during this whole blower conversion deal.

Jim

WHEN you get it Jim! Lets think positive now! You're almost there now with it underdriven.

[GTOGEORGE]

Originally Posted by twooldgoats

Went out to make some TNT passes at SIR with the new simplified tune. The first pass was a 9.41 @ 143. WTF!!!!!! I did get some EGT data on the pass, though, and noticed an oddity: neither cylinder #2 nor cylinder #3 got above about 100 degrees. I wasn't sure, of course, if it was a problem with the EGT senders or a real problem. When I pulled the plugs, neither one of them looked like they had fired. I rechecked the resistance of the two plug wires. They were both OK. Then, I called my engine guy, Paul Carter, and he suggested checking them with a timing light to make sure they were both firing. They were. Hmmmmm...... What if the cam manufacturer screwed up and my 2-3, 4-7 swap cam was really just a 4-7 swap cam? I switched the #2 and #3 spark plug wires and fired it up. It definitely sounded crisper.

So, I made a pass: 8.287 @ 167.88 mph. That's more like it. We leaned it out just a little more and went 8.254 @ 166.07. Not sure what happened with the mph there. The ET was a little better, but the mph slowed, even though I was 133.01 mph @ the eighth mile on that last pass, compared to 129.64 on the other good pass.

As it turned out, my 9-second passes the last two times out were on six cylinders! I'm still having a ton of trouble getting good EGT data, but what I was able to get showed no cylinders over 1,000 degrees. I may not be getting full pass data, though.
I sure wish now I had just skipped the Red Alert system and added EGT sensors to my Racepak. The Racepak seems to be working fine.

So, I've gotten a lot closer to my goal of a seven second pass. There's a lot of tuning left to do and I'm under-driving the blower 10%. The density altitude was over 5,000' for my 8.25 pass. The car ran absolutely straight and felt great. My 60-foots, 1.279 & 1.259, have a long ways to go, but I'll worry about that later.

Jim

So what kind of boost numbers are we talking about? It's kinda weird that your MPH was down on the next pass.
I like what you are doing taking your time.


GTO George

[vin63]

Originally Posted by twooldgoats

...So, I made a pass: 8.287 @ 167.88 mph. That's more like it. We leaned it out just a little more and went 8.254 @ 166.07. Not sure what happened with the mph there. The ET was a little better, but the mph slowed, even though I was 133.01 mph @ the eighth mile on that last pass, compared to 129.64 on the other good pass.

That's around a .01% difference…could be wind. Did you notice any drive shaft speed anomalies on the data logger between the two runs? My time slips at old LACR were all over the place despite running within a couple thousands of the class index because of the high winds at the top end of the track. Glad to see you're making progress. How did the bearings look? Lugging the engine like that with a couple of cylinders out can be hard on bearings.

[twooldgoats]

Originally Posted by GTOGEORGE

So what kind of boost numbers are we talking about? It's kinda weird that your MPH was down on the next pass.
I like what you are doing taking your time.


GTO George

Boost was highest (12.1#) when I was on the limiter at the starting line, then dropped to 9.2# for the whole rest of the pass, dropping to zero at the finish line. The constant boost level really surprised me when I saw it. I guess I expected it might be proportionate to engine speed or something, rather than constant through the pass.

I only recovered data for one of the two "good" passes, so I can't compare them on the Racepak parameters. I decided to start the Racepak manually before the burnout from here on out to eliminate all the data clutter I'm getting on the SD card by having the Racepak start every time the ignition is on or the engine is started. Just another thing for this old man to remember. I'm still trying to work my way through the 82-page manual for the Racepak software. I ended up with several minutes of data of me driving up to the line and back down the return road.

The mph thing makes me wonder, too. Based on the 1/8 mile difference, I should have been over 170 mph on that second pass for the quarter mile. At this point, I'm just trying to tune the A/F ratio and pump pressure well enough to arrive at a good basic tune that doesn't destroy parts. Then I'll start working on my 60-foots and incremental times to see where I can get better.

Jim

[twooldgoats]

Originally Posted by vin63

That's around a .01% difference…could be wind. Did you notice any drive shaft speed anomalies on the data logger between the two runs? My time slips at old LACR were all over the place despite running within a couple thousands of the class index because of the high winds at the top end of the track. Glad to see you're making progress. How did the bearings look? Lugging the engine like that with a couple of cylinders out can be hard on bearings.

The wind wasn't a factor. It was very still. The thing that made me wonder about the speed is that I was up more than 3 mph at the 1/8 mile on the second good pass and then down slightly at the 1/4 mile. I don't know what to make of that. It seems like the second pass should have been over 170 mph.

You asked how the bearings look. I have no idea. I don't generally check bearings unless the engine freezes up or something comes out of the side of the block or through the oil pan. I wonder, too, about the effect of running with two dead cylinders. We did pull about a half pint of alcohol per pass out of the puke tank while the engine was running on six cylinders. I thought at the time it was the over-rich tune, but it was probably the dead cylinders. After the last pass, I only got a couple of drops of alcohol out of the puke tank (and no oil).

The uneven operation with two cylinders out couldn't have done the engine any good, but at least we're not talking about detonation. The spark for cylinders two and three would have come at the end of the exhaust stroke. I wonder about unburned alcohol washing down the cylinder walls, etc. I do plan to check compression and leak down before I go out again.

Unfortunately, I can't compare the two "good" passes on the Racepak, because one only got data for the shutdown, not the actual pass. I'm also having trouble figuring out how to clearly label times on the passes, so I don't confuse passes. The original recording on the SD has the times, but somehow I'm unwittingly changing them when I load them into my computer. I erased the SD card before I realized that. I guess I need to get back to studying my manual.

Are you planning on Pontiac Heaven this spring?

Jim

[twooldgoats]

These are the time slips for the two "good" passes, for comparison.

Jim

[vin63]

Ah, yeah the data logger information would be more helpful in this instance…when we needed it most, is when out data logger would also glitch.

I would be concerned about fuel wash and if the bearings sustained damage when it was lugging during those 6 cylinder runs. We always had some bearing damage during our slower runs when we put out a cylinder(s) - that 7.20 pass when I pedaled it twice at the last Pontiac Heaven we put out 3 cylinders, spun a bearing and cracked the crank. All of our quickest runs, our bearings were always cherry. The unequal load is murder on parts.

We're most likely a no go for PH next year...making the switch to Chrysler since we've run out of Pontiac blocks.

[johnta1]

making the switch to Chrysler since we've run out of Pontiac blocks.

What blocks do you use?

I have a few blocks.

[Steve Barcak]

Congrats on your progress Jim. It looks like you will be changing pulleys soon.

[twooldgoats]

Originally Posted by Steve Barcak

..... It looks like you will be changing pulleys soon.

I just ordered a 34-tooth (1 to 1) pulley this morning, but I won't use it until I get the tune-up straight for the 10% underdrive. When I do that, it's relatively simple math to change the tune for weather, elevation and pulley changes.

It looks like I didn't do any damage with the six-cylinder passes: nothing in the oil filter, compression good in all eight cylinders and the plugs still show very little heat. I spent more time on the phone with Altronics yesterday trying to sort out the problem of not getting good EGT data and I think I may have made some progress. They did e-mail a manual for the Red Alert system that is more up to date than the one that came with my system and the one they offer for download on their website.

Jim

[Elarson]

Originally Posted by vin63

...making the switch to Chrysler since we've run out of Pontiac blocks.

Ouch, that's disappointing. We've admired your program. An IA2 block is cheaper than a Chrysler engine.

Eric

[vin63]

I would pull a few of the caps to visually inspect the bearings just to make sure. We've caught some blackening of a journal with no debris in the filter.

Originally Posted by twooldgoats

...It looks like I didn't do any damage with the six-cylinder passes: nothing in the oil filter...

[Jack Gifford]

Originally Posted by vin63

... making the switch to Chrysler since we've run out of Pontiac blocks...

So... how many stock 392 blocks do you propose to consume?

[GTOGEORGE]

Originally Posted by twooldgoats

Boost was highest (12.1#) when I was on the limiter at the starting line, then dropped to 9.2# for the whole rest of the pass, dropping to zero at the finish line. The constant boost level really surprised me when I saw it. I guess I expected it might be proportionate to engine speed or something, rather than constant through the pass.


Jim

Thats a good thing constant is what you want.................my boost only varies 1 pound of boost from start to finish!


GTO George

[twooldgoats]

We made three more passes today: 8.21, 8.24 and 8.19. I set the shift point up from 7200 to 7500 before we started and we changed the launch RPM from 3500 to 4000 on the third pass. We tried a couple of different tire pressures as well. It looks like I got good data on both the Racepak and the EGT system by turning them on right after my burnout each time. I haven't taken a good look at them yet. I'm not happy with my 60-foot times, so I'll think about that in the upcoming week as well. We would have made a fourth pass, but one of the guys at the line saw a bolt fly out while I was doing the burnout and gave it to Ellen after my pass. It didn't look familiar, but we decided to call it a day. I've made eight passes with the new combo, so it's a good time to put it up on jack stands in the garage and have a look around anyway.

If all that goes well, it may be time to turn up the wick a little and drive the blower one-to-one next time.

Jim