I was already confused when I got my timeslips the last few weeks, but after more analysis and seeing how poor my info looks on the Stock Turbo list relative to others, I decided to delve into it further while also asking for opinions from others.

This is perhaps even more specific to just the RM Shootout on Friday of last week, but it may hold true to Bandimere (Denver drag strip) as a whole on any night (this season anyway). What I'm trying to figure out is if the trap speed indicators were off during the RMS event, or if they have been off all year maybe. Here is my evidence, and I'm hoping others can add to this, because my findings are not conclusive and are quite confusing.

Previous best (before 2008) ET and trap at Bandi and PMI (other local drag strip), respectively: 12.30 (1.72 60')/109.5 and 12.41 (1.71 60')/109.5
Add 68whp/62wtq, and...

Previous best (within a month before RMS event) ET and trap at Bandi and PMI, respectively: 12.04 (1.69 60')/116.3 and 12.13 (1.75 60')/115.6
Add no power or mods but change from aggressive race alignment (-3.0f/-1.2r camber and 1/16" toe-out front) to street alignment (-1.5f/-1.0r camber and 0 toe all around), and...

Best at RMS event at Bandi: 11.84 (1.74 60')/118.99

At RMS, I ran three 11.8s and a slew of 11.9s, so it wasn't a one-off thing. Also, I hit an 11.84 on the left and 11.85 on the right, so I don't think there was a lane discrepancy. However, my highest trap on the _right_ was a 112.88. Look at this compilation of timeslips (2 left lane/1 right lane):



Notice how the 60', the splits, the 1/8th mph, and the 1/4 ET all jive, but the trap is WAYYYYY off. Even if you look at the time difference between the 1/8th and the 1/4, you'll see there is almost NO difference: 4.30s, 4.35s, 4.38s. That does not show a 6mph difference. Strangely, though, my buddy Corey in the white Evo was seeing identical traps in both lanes unlike me. He was seeing 115-116mph traps on both sides with 11.9-12.1s on just about every run. How is this possible? Yet another factoid is that he has a slightly bigger turbo and has trapped higher than I have at every previous trip to the track (3 total in the last month), and when we ran side-by-side, I did not pull on him in 4th. We were either dead even in 4th, or he was slightly pulling, but there were usually other factors playing into that such as who got off the line best or who shifted best. However, I was by not pulling on him at the end like you'd expect with a 2+mph advantage, and we ran each other about 5 times. I do believe I got quicker/faster from one night to the next due to my alignment changes, but I do NOT believe that my traps were really that high EITHER night. I think they are 2mph higher than actual.

My raw (uncorrected) WHP/WTQ was 324/341 on the local DynoDynamics the day after the drag eventm, and I weighed in at 3300 w/driver. That should equate to 115-116mph traps, not 118-119. At sea level on a DynoDynamics, cars with that power level uncorrected do not hit close to 118. Likewise, a ~60whp gain should glean ~6mph gain over previous. I never quite did 110 before with 262whp (uncorrected on same dyno), so I would expect around 115-116 now.

Lastly, I have a ton of experience with drag racing 4 different cars - 3 were AWD/turbo 4g63s. I not only know my car and my driving, but I pay close attention to other cars all around the country to understand what makes sense and what doesn't as you guys know. I closely analyze 60's, splits, and final et/mph while taking into account weight, gearing, weather conditions, track conditions, etc. What doesn't make sense to me is how I would only be hitting 11.8s with such a huge mph and a decent 60'. In all honesty, with my typical driving/shifting, even a mid 1.7 would be an 11.6 with a 118mph trap and maybe even an 11.5 with 1.6, though I was unable to do that without a sticky launch pad. To get an 11.8-11.9s with 118+ traps would require either a much worse 60' or terrible shifting. My shifting has always been very fast, and I'm not even having to shift to 5th like I used to, so I'm very skeptical of my trap speeds. It would make much more sense if I were doing 11.8s @ 116 with mid 1.7s - that makes tons of sense. Likewise, my previous 12.04 @ 116.2 with a 1.69 makes much more sense if it was a 12.04 @ 114.2, because that's exactly where I should be with a 1.69 60'. Hell, I ran a 12.000 @ 113.7 with a 1.66 staying in 4th before I moved to Colorado, so that's why I'm confused.

Look at the et/trap comparisons of those on the 2008 Stock Turbo list for reference. Thoughts?

 

Direct comparisons of timeslips:

Timeslip-----Warrtalon--Fathouse1--Fathouse2
60---------------1.74---------1.70----------1.73
330-------------4.91----------N/A-----------4.88
1/8--------------7.59---------7.57-----------7.51
MPH-------------93.14-------90.87---------93.35
1000------------9.90---------9.89----------9.77
1/4--------------11.84--------11.85--------11.68
MPH-------------118.65------115.63-------118.10

Now, I'm not saying it's impossible for Fathouse (or anyone else for that matter) to outdrive me (outshift mainly), but I _am_ saying that it's highly unlikely that I'm going as fast as the trap speed says I am. Fathouse's slips are perfect for my comparison, because he has one that shows the mph where I think I am and one that shows the mph where my slip says I am, but the ETs are much different than what I have.

First off, his slower run had a better 60' (by .04), but then I reel him in and win by .01 on the ET. This does show that I'm probably a little faster mph-wise, but not 3mph faster as the 1/8th and 1/4 indicate. We're talking a mere 5 hundredths of a second gained, yet I'm supposedly going 3mph faster for more than half the track? Notice we both gain 25mph on the top end, yet I only outrun him by .03s. There is only one shift after the 1/8th, and I no-lift the dog mess out of my 3-4, so there's just about no way to only gain .03s on the top end when going 3mph faster the entire way.

On his faster run, his 60' is almost identical, yet he is pulling away from me at every split despite his trap speed being LOWER. He again picks up almost 25mph (like me) on the top end, yet he outruns me by .08s. So, I'm supposedly going faster at the 1/4 and accelerating more from the 1/8th to the 1/4, yet he outruns me by a tenth during that same timeframe. Again, there is only one shift here, and I no-lift the 3-4. Plus, I only outran him by .03s earlier with what we're led to believe is a 3mph advantage, yet he outruns me by almost a tenth with a lower mph throughout.

What this leads me to believe is I'm actually trapping in the low-to-mid 116s with there being a discrepancy on the timers. Anyone else?

 

On the 3rd 112.x pass, was that immediately after other passes? I thinking about heatsoak type issue. Did you make logs of the runs so you can review timing/boost? I saw something similar, but it was a boost leak appeared after a few other passes. MPH dropped by 3-5 mph. Was the 112 pass the last of the day, or did other 'good' passes mysteriously re-appear?

 

Actually, my 118.99 on the left was after 8 straight passes - my MPH kept going up. I did 5-7 runs on the right with all being 112s, but the ETs were the same as the left. Even the 1/8th MPH was the same as the left, but the 1/4 mph was always very low. I can't log boost, but my timing was always beautiful with little-to-no-knock (never enough to trip the Knock CEL). The traps on the right would be low whether it was a hotlap or after a cooldown period. Overally, I did about 30 passes, so there were no one-off anomalies - these were consistent results.

Later in the day, as it got warmer, my traps dropped to high 116s on the left and 110s on the right with 12.0 ETs.

 

I noticed that the right slip, although showing higher mph in the 1/8th and probably entering the 1000' higher, does show slightly slower et from 1000' to the 1320. This would be a 'minor' indication that something was happening in 4th gear pull. 1.953 et vs 1.94 vs 1.94. (time from 1000 to 1320)

 

Didn't notice, but any tire differences? tire height, compound etc? We experience a mph drop vs et recently, but it was directly related to the turbo thrust bearing not allowing the turbo to spool up between shifts.

 

Yes, I showed the 1/8th to 1/4 differences, and the one on the right was .03s slower than the 118.77, but that tells me maybe 1mph slower (high 117 relative to the high 118), not 6mph slower...

 

This was all done on the same day, and I could do a 118 on the left, 112 on the right, 118on the left, and 112 on the right in 4 successive runs. All through the day, the ETs and 1/8th traps were identical, but the 1/4 mph was always 6 lower on the right.

In fact, the 3 timeslips you see above were all within a 15-min period of time.

 

I think this comparison might settle it. This is including my one 11-sec run at Fontana at 1200' elevation a few months ago:

Here is that timeslip from Fontana appended to the earlier comparison I made:

Timeslip-----Warrtalon2(CA)--Fathouse1--Warrtalon(CO)--Fathouse2
60---------------1.76----------------1.70---------1.74---------------1.73
330-------------4.99-----------------N/A----------4.91---------------4.88
1/8--------------7.70----------------7.57---------7.59---------------7.51
MPH------------89.00---------------90.87-------93.14-------------93.35
1000-----------10.01---------------9.89---------9.90---------------9.77
1/4------------ 11.97---------------11.85-------11.84-------------11.68
MPH-----------115.36-------------115.63------118.65------------118.10

From this you can see my run in CA is much more normal. I didn't have a great launch, but I had fairly normal shifting. I was just a little slower than Fathouse and was .06 behind from the launch, so it makes perfect sense that I would lose by a total of .14 - some from the 60' and some from the slight speed difference. It's also obvious that my car definitely is faster now than it was in CA even with the altitude change, but I do not think it by any means is fast enough to trap basically 119 flat. Notice my time from 1/8th to 1/4 in CA is 4.27 while going from 89 to 115.4. Up here, the time was 4.25 while going from 93.1 to 118.6. I think this again indicates a likely low 116mph trap speed like all the other things I've pointed out.

 

Believe me I'm no expert, but I was going to say that possibly you were pulling timing in 4th, but you said it trapped very closely in 4 consecutive runs using each side. Maybe the indicators are slightly off in both directions for each side.

In regards to gaining the mph with the new mods, running the car to redline and the 1 less shift might result in more of a mph increase than just the raw numbers show. So, with 60whp gained and longer gearing and one less shift, shouldn't you see more than a 6mph gain? Maybe thats why you are seeing 118 traps instead of 116.

 

Both of your points are very valid:

1) I didn't just run 4 - I ran 8-10 straight as soon as the event started, and my MPH was actually going UP each run to a max of 118.99 at its peak, and this was with runs in both lanes. Of course, the ones in the right lane were 112s while the left lane showed 117 on the first two and all 118s after that. This is a testament to the ETS 3.5" FMIC, imo. I think you're right, though. I think BOTH lanes were off, and that my true mph was in the middle somewhere at 115-116.

2) Yes, that's another great point. I didn't just gain power but also have different gearing. Even moreso, I am down about 75lbs race weight, which is almost another mph or so (~.75). However, on the flipside, I have always experienced about a 1mph drop in trap speed when shifting to 5th, so I believe I would have been trapping higher than 109.5 before had I not been shifting to 5th, so it's kind of a wash.

 

In absolute honesty, I think it's something in the tune. Just sucks you weren't able to log any of the runs.

-E

 

Explain what you mean. I've never heard of nor seen an example of where a tune gives crazy trap speeds without it reflecting on the dyno or in the timeslip (at every split). Same tuner for both the 11.97 and 11.84, too...

Whether at PMI tomorrow night or Bandi next Wednesday, I'll be sure to get some logs.

 

Give you an example in words the best I can...

If you are knocking, you're going to be pulling timing. It's a given. In the morning sessions, the car ran quicker because it was cooler and the car liked the cooler air and did NOT pull AS much timing. Not to mention that throughout the day as it got warmer, you got slower. This COULD be a result of heat soak on top of the knocking on top of the timing. This is all speculative until we can see logs.

I'll explain it tmw if you need me to.

-E

 

Well, of course you pull timing if you're knocking, but you don't trap higher than ever if you're knocking and pulling timing. In fact, such an instance would affect the traps MORE than ET, because it wouldn't become as much of a factor until the top of 4th well after the ET has been established (first 330' mainly).

Yes, as it got warmer, I got slower, but so did most people - that's normal. Additionally, as the day went on, my 60's got worse and worse due to spinning, which made it difficult to get up to speed all the way. I didn't have logs of the timing, but my knock CEL is set to come on at 6 counts, and I only saw it come on once.