AlkyIROC

First thing I did this morning was take my car over a scale. Got some weird readings.

Drove the front onto the scale, 1807 pounds. Drove the whole car onto the scale, 3086 pounds. Drove off the scale and stopped leaving the back wheels on, 1300 pounds. All weights are with me in it.

Front and rear don't add up. If someone asks what my race weight is, I'll say 3100 pounds. For ET calculations in my laptop, it's 3086. Either way, it's heavier than the 3042 last year. The new cage added a bunch of weight but the aluminum center section and spool took a little bit off as well as the aluminum sheet metal over the back half.

Hot and sunny today. Great day for racing except for the head wind which was slowing everyone down. Most of the day it was 25 gusting to 35 Km (roughly 20 MPH head wind).

2 time trial runs.

First pass right off the trailer. Haven't raced since the end of September last year.

RT - .035
60' - 1.377
1/4 - 9.504
mph - 142.58

It just about starts exactly where I left off last fall. Over the winter I changed the gears from 4.86 to 4.57. RPMs stay roughly the same as before all the way down the track except it pulls a little longer in first gear now and just past the 1000' mark, I can feel it pulling harder instead of nosing over. I may have to put the 4.86 gears back in because the new heads I have on the engine really want those high rpms. I was only shifting at 7200 and could easily take it to 7600. At least with the 4.57 gears, I'm not spinning off the line as much.

Second time trial. Almost a carbon copy run.

RT -004 oops
60' 1.368
1/4 - 9.522
mph - 142.26

First round eliminations. Dialed in 9.52. We were laddered in the first round and my opponent didn't make the call. Free T&T pass. I got way out of the groove which slowed me down.

RT - .065
60' - 1.373
1/4 - 9.601
mph - 141.84

How much was from the head wind? How much was from being out of the groove? Take a gamble for the second round and dial up to 9.59

RT - .045
60' - 1.382
1/4 - 9.527
mph 142.22

Ran the same as the time trial runs and broke out big time. I knew it by the time I was at the 1000' mark. My opponent was asleep at the tree with a .221 light but I still kept my foot in it. Oh well. At least I now know the car is running consistent 9.52's today at 142 mph.

It's now middle of the afternoon and there's gaps between the rounds for some T&T. I rechecked the timing. It was around 38, maybe 39 degrees. Dropped it down to around 34 degrees and made another pass.

RT - .026
60' 1.384
1/4 - 9.476
mph - 142.87

The engine definitely liked less timing. Since it was a solo run, I pulled the chute at the finish just to say I have used it. The Stroud chute is so gentle when it hits you hardly know it's there other than you're slowing down faster than if you were coasting.

I could have bumped the timing up a couple degrees more and made another pass but there was a thunderstorm building and they wanted to pack up as soon as possible. I packed up the chute, loaded the car and went home.

No breakage, no oil leaks. I did everything perfectly such as turning on the replay tach, arming the vehicle reaction timer etc on every run. The only thing I screwed up on was the dial in on the second round and on every run, I still fail to look at the EGT gauge as I cross the finish line to see if the engine is running fat or lean.

I got in car video of all 4 runs but haven't watched any yet to see how it turned out. Other than that one run where I got out of the groove, they should look great. Will post links later when I get at least one online.

So 5 passes down the track today. One red light during time trials (throw it out since it was only red by .004). 4 good reaction times of .035, .065, .045, .026. Not bad considering I haven't raced in 10-1/2 months. That's an average of .04275. I have 1.055 in the delay box and will probably take that down to 1.045

sailtexas186548

iTrader: (2)

glad to hear you made it out finally, seems like you have had nothing but set backs this year

brandoz28

iTrader: (1)

i got double bulbed on saturday in the semi's which sucked... had a .004 .006 .008 lights and then a .033 the first round and another decent light the next, then ended up going red after getting double bulbed to a guy who ran .1 off his dial with about a .150 light...i had about a .02-.04 package all day and threw it out. that's racin!

ZONES89RS

iTrader: (2)

Thing is pretty consistent!

five7kid

iTrader: (14)

When people double bulb me, I just take my sweet time lighting the first bulb. Auto Start doesn't start until both prestage bulbs are on. If I hear they're up on their converter, I really creep up slow to the first bulb. I just make sure I'm completely ready when I light that first bulb so I'm ready when I finish staging.

Most people that double bulb me end up losing.

AlkyIROC

The only time I double bulb is by accident. 3 of my 5 passes yesterday had someone in the other lane. I'm sure I was the first to prestage every time. I always do courtesy staging. Prestage then sit and wait for the other prestage to come on before staging. Using the bump button and the starting line enhancer, I'm sitting at an idle the whole time so my opponent can take all the time in the world, it doesn't affect me. Once both stage lights are lit, I concentrate on the top amber. When it lights up, the transbrake button is released, the engine goes to WOT and I sit and wait for the delay box to release the transbrake.

I looked through all the video I shot. I think the camera mount is loose. All the video's are shaky and the last few runs when I had a dial in on the window, part of the shot is blocked. It looks like the best video worth posting is from the second time trial run. It seems to be the most stable and has a good clear view out the window. As soon as I edit it down in length and reformat it, I'll post it online. Might not be until tomorrow night.

I did a bunch of number crunching last night. Dropping the timing down from 38 to 34* gave me around 20 more HP. It helps if the car can make back to back identical runs to know if changing something actually makes a difference to the run. Going from a bunch of 9.52 runs then changing the timing and running 9.476 with the same 60' time as the previous run tells me the timing change made a difference.

The corrected HP compensating for altitude and the increased car weight is still lower than what it was last fall but not by much. Best corrected HP I got last year from ET was 833.75. Yesterday it was 821.16. Yesterday's best MPH calculated to 804.62 which was slightly better than last year. The diff gear change probably had an influence on that also. Since the numbers are not the same, my MPH is still slightly slow for the ET. Yesterday's head wind probably killed that. Actual uncorrected HP numbers from yesterday on the last run are 716.82 from ET and 702.38 from MPH. Racing at altitude loses a lot of power.

Yesterday's times were a little slower than my runs last fall but the density altitude was also at least 1000' higher yesterday. Technically it's running faster. The car is heavier, the DA was higher and I was still running roughly the same speeds. Some cooler air should show better results. I think I'll also lean down the fuel mixture for the next race.

I still have more number crunching and things to check out and analyze to see how well the car performed. The setup still isn't perfect but it's getting better. I need to video the playback tach on the last run I did and inlay it into the in car video. I want to see what the car is doing in relation to the rpms as it's going down the track again. Last years video that I did like that is still my favorite.

A bit more number crunching. MPH of five runs with the last run having different ignition timing.

142.58
142.26
141.84
142.22
142.87

Average 142.35 MPH. Even the 60' times were remarkably consistent for a change. Track prep was good but our track isn't known for great traction.

1.377
1.369
1.373
1.382
1.384

Average 1.377

AlkyIROC

First video is now up on youtube. This is the second time trial run. Ignore that .004 red light

http://www.youtube.com/watch?v=SHKnMDthY3E

The same video is now also available on Streetfire

http://videos.streetfire.net/video/C...009_695344.htm

brandoz28

iTrader: (1)

yeah i let it get to me, i really shouldn't have, but i did. a big part of it was being in a car that's still a little unfamiliar to me. worst thing is the car runs close enough just flashing the converter or stalling it way up, so i would have been fine if i wouldn't have let him get to me a bit. looks like i'm taking taht car to cordova this weekend to try to make a little cash

Shagwell

Congrats on finally getting out this season. I'm finishing putting my junk back together(again) now.

That's definitely some good numbers to come out of the gate with. With some tuning alone I think you'll shift on down into the lower 9's, better air will help even more.

What size slick are you running?

AlkyIROC

I was running 9.3 - 9.4's last year. Over the winter I changed the heads from unported Canfield 310's to massively ported Dart 360's and also went from a 2.25 intake to a 2.30 intake. The diff gears were also changed from 4.86 to 4.57. Those 2 changes means that last years numbers don't really mean much plus the car is heavier. I'm starting from scratch again for tuning. These new heads may need a bigger cam. The one I have now is .748/.748, 286/298 @ .050. The biggest I can go with the current valve springs is one size up. .800/.748 with the same @ .050 duration. My current cam makes power to 7500. The next cam makes power to 7800 where the heads probably want to go. There's a couple of cams that will rev higher but they're for smaller and lighter cars.

Slicks are MT 32 x 14 mounted on a 15" rim.

Shagwell

Good baseline to work from though. Obviously it's not too far off, as the consistency isn't. I'm sure you know this, but find the motor tune, then go after the chassis a bit. You should be able to find another tenth or close to it in your 60ft, that plus finding a good engine tune could make for low 9's w/o changing any parts.

AlkyIROC

Second video is now online. Last test and tune of the day and I did an overlay of the tach for that run. I think it's synced close enough to the audio. The camera sure was jumping around a lot but it's still watchable.

I pulled the chute on this pass but didn't pull it until after I crossed the finish line. I'm hardly touching the brakes as the car is slowing down. If I pulled the chute just before the car crosses the finish, I could easily take the first turn off with only medium brake pressure.

http://www.youtube.com/watch?v=m9FtcbjwwDc

Same video on Streetfire
http://videos.streetfire.net/video/C...ach_695515.htm

Primetime91

iTrader: (15)

Thats what my car wants to be when it grows up!

DIGGLER

iTrader: (1)

what kind of converter are you running? wonder if the car would work better with a tighter one?

AlkyIROC

Watching the replay tach, just after I launch, the rpms jump to 6100, stay there for a while as the car picks up speed then slowly climbs to the shift point around 7200 rpm. When I shift, the rpms drop to around 6300.

I don't think I've ever done a full transbrake stall to see what the stall speed is but I can assume it's around 6000 rpm.

Based on best performance last year, the converter slip was only 4%. Now with the 4.57 gears instead of 4.86 and shifting at 7200 instead of 7400, converter slip is now calculated at 6.4%. I think that's still more than tight enough.

Although the temperature is going to be really hot tomorrow, I may go out for the Friday night street legals to get some track time and tuning. It's probably going to be a zoo and there won't be any track prep. As long as I can keep the car straight, spinning tires won't hurt the MPH which is all I want to see when tuning. If performance still isn't the way I like it, the 4.57 gears are coming out and the 4.86 are going back in. I wanted the 4.57 to bring the rpms down however the new heads want more rpm. I don't think I can justify 5.13 gears yet unless I get a camshaft that lets me spin the engine to 8000. Different dyno/dragstrip programs all say 4.86 is too much gear.

Providing I can get to the track tomorrow night, I want to play with launch and shift rpms and I want to lean down the engine but really need to watch the EGT to see how hot it's really getting. Leaning it down in the heat will be a good thing anyway. The DA will probably be higher tomorrow than it was last Sunday when I was at the track at 5500 feet.

Shagwell

I've got a hand held EGT set-up made by Fluke, similiar to their multi-meter electrical testers. I love that thing; dual probe inputs and a record button. No time to see it going down the track, but I can hit the record button just before rolling in to stage and review the entire run afterwards.

AlkyIROC

That's something I could really use.

Even better would be a data logger that records all sorts of stuff plus 8 EGT probes. Something like that is a little pricey for the average bracket racer. There are some simple data loggers and some really high tech ones.

I may look into the fluke meter. Having it record would be better than just seeing a peak number.

Shagwell

The full data loggers are definitely very nice, but carry an according price as well.

Currently I log EGT via the fluke set-up and log o2 with a innovative LC-1. When the blow motor goes in I will switch to a different o2(for the methanol) that has a couple other log channels available, so that I can log boost and rpm as well. RPM, boost, egt, and o2 will pretty well cover me. There are a few systems that will record 3-4 channels for considerable less than a full-on Race-pack type system.


This pic shows that Fluke metere: