So, up here in poor air the car went 12.88 @ 106 MPH. Nothing special but...
I've been keeping track of time slips and have been correcting them sea level. In doing so I can see improvements made in the car's development.
Case in point:
2014 in Ontario (Canada not California!)
14/08/23
630’ (track elevation), 66.2F/19C, 30.09” Hg/101.9 kPa, 94% rh
DA: 1321'
12.641 @ 106.82, 8.043 @ 85.73, 1.85 60’
12.461 @ 108.379 MPH corrected
Then across the country to my new home:
15/06/05
2210’ (track elevation), 59F/15C, 29.91” Hg/101.29 kPa, 51% rh
DA: 2855'
12.92 @ 104.87, 8.21 @ 83.77, 1.85 60’
12.479 @ 108.653 MPH corrected
12.93 @ 105.46, 8.23 @ 83.15, 1.85 60’
12.489 @ 109.264 MPH
That was the same car, no changes other than the track and it all played out identically.

Yesterday that 12.88 @ 106 was at a 3900' DA.
Correcting to sea level and I get:
12.22 @ 111 MPH.
So, the fresh short block, same tired heads albeit with a little pocket pocket (but never tested), properly spec'd cam, new transmission (and it's excellent) and a spec converter and I'm seeing a 2/10th's improvement and 2 MPH.
Considering that there was no tuning whatsoever I'm encouraged by the results.
60' was disappointingly awful at 1.86. Again though and I was just doing hot laps, the air bags were at 0 PSI and the squat at the hit was noticeable. New drag radials too which are completely different animal to the bias slicks I'd been running.

I'll venture a guess and say that if I make the trip to a sea level track (12 hours across the Rockies) or get back to my Ontario home in the fall for some typically nice air (2200 miles cross country) I'll get that 11 second time slip.
Getting the 60' even back to personal best of 1.7 flat, will net that top end improvement needed. Engine tuning should gain even more.
Target: 11.99 @ 115 MPH.
Keep in mind that this is a carbed 357 in a 3500+ lb car.

So after 10 years of no track time, I AM finally back!

 

2855 is poor air? LOL. Back when Calgary had a track, the track elevation was something like 3300 and most race days, the DA was around 5000. On a bad day it was over 6000.

Edmonton's track is around 2500 and bad air is around 4000.

I'd love to race in Mission BC. Track elevation is 35 feet and spring and fall when it's cool, the DA can dip well below sea level.

 

I think you missed it Alky.
DA was 3910' on the day I raced last week. Not the slip from 2015! (LOL not). The Radraceway App lists it in the bottom right of that screenshot "timeslip" I posted.

I also use air density online's data.
Rad Torque's historical data from that evening is at this link.
https://airdensityonline.com/track-h...ay/2025-09-19/

At 6pm, DA was 3910'.

I've often mentioned Mission as my sea level go to track. 12 hours across the mountains and an overnighter would take some planning though. But it is on my radar.
Ontario in the fall is also a return trip I'd like to make. A ripe fall day at Cayuga (known as Toronto Motorsports Park despite being 100 miles from Toronto) might have a DA below sea level.

 

Man...your ET's are over 1/2 second quicker than mine on the same ET! When I ran my car in 'Vegas (2200' elevation, 100*F), I went 13.5x (my quickest ever in this car) at 105.x...my fastest ever in this car. On that "105", you're going 12.90's. Pretty wicked.

My home track closed, it was RMR in SLC...4200' elevation and DA's were 6-9000'.


Super cool to see that you're out there DOING it...making memories.

 

The car has always had a MPH that showed that's there's improvements to be gained with respect to ET.
This uncorrected time from Ontario is still the best time slip ever.
12.641 @ 106.82, 8.043 @ 85.73, 1.85 60’.
But that's the thing, take the air of the day and factor that in (whatever some of my racer friends might say) and this last outing is the best ever. That said, at a 4000' DA, it still went 106 MPH. Uncorrected. So there's something to take away from that.
But as of this moment, I need to work on the 60'. There's easily 2/10ths there.
Maybe this Saturday...

 

Surprised the 60 is that low for the et.

my bolt on 99 ls1 car was in that mid 12.5 range at 108 with low 1.7x 60’s at 1500-2000 da. At a sealevel track in negative da it trapped 110 and was 1.66-1.69 60s and 12.3-12.4 i think.

Your car seems like it makes up for it between 60-330. 1.80’s seems slow

 

With regards to 60', absolutely my thinking. 1.8x is terrible.
I have gone 1.7 flat although that was with different tires (McCreary Road Star dirt track tire), less power and a 3.27 gear compared to the 3.73 I have now.
That said, I think with the airbags preloaded to lift the back
end, it should take away the squat at the hit. The LCA angle is just about horizontal with the bags deflated despite being in the lowest hole on the relocation brackets.
As for 60-330', I've never examined it in a comparative way.




I also trying to get a handle of these MT ET Street SS drag radials. The burnouts are confusing and I didn't have a whole lot of time experimenting.

 

Analyzing all of the break outs can be incredibly interesting and educational.

 

That's a GREAT spread sheet!
While I had intentions to get to the track for the season finale on Saturday, I've resigned myself to servicing my daily driver Tahoe. I still have to get to work! So there's goes the weekend.
But now that I've got my baseline, I've tons that I can work on from a track perspective.
I'll have to develop a better database once racing resumes in the spring. I've also got datalogging capabilities although a few more inputs, other than the RPM and MAP I presently have, will need to be incorporated. AFR is a big one.
Thanks for posting that Tom. I'll get into in a deeper way when I can focus better.
One take away I see (other than a better DA) is "better driving". There's a surprising amount of rust that can accumulate after a ten year hiatus from any track time. I couldn't cut a light to save my life. Except against that late model turbo Coyote Mustang Cobra. I got him by 3/4 of a second in the first 60' but by the time I was at 105 MPH, he FLEW by me at 133! He doesn't' need a good light.

 

Love the spreadsheet. I have something similar but not as detailed. Is it part of a program or do you manually enter all the data, insert new columns etc?

Breaking down the run in sections allows you to see where the car picked up or slowed down during a run.

Looking at all those numbers, its interesting that your MPH from your best run is almost identical to your 5 T&T passes where you ran better ET. HP is remaining constant across the board so better ET must be from traction.

 

Thanks guys, hope the sheet helps. It's not a program, just an excel spread sheet. I don't deserve credit for it; I copied and modified Ranger's sheet, per his advice.

Getting into the actual numbers...it's kind of nuts. I built that sheet to help me figure out why I couldn't get into the 12's with my C6. Everything was 13.0x@108-110. People convinced me that it was "Tq mgmt", which the break outs actually show that could be the case. Guys proved to me, mathematically, that the car would go faster if I raised shift points from 6000, to 6500, so I did. Then there is the DA. What's nuts (and one of the many things that irritated the hell out of me, about that car, is like you said; look at the all of the factors!
1. I went 5 passes in a row, in the 12's....on the same trap speed.
2. on the 13 pass, I 60'ed .2 slower than all of the others...but only ran .1 quicker? On the same trap.
3. DA!! 13 second pass, 7800' DA. 12 second passes, ~6000' DA....zero difference in trap. WTF.
4. Raised shift points to 6500.....= zero improvement in trap. WTF, II. (know that one isn't shown in the spread sheet, but I did that).

Yeah....that car was super annoying. I don't miss it at all. I got my 12's...but I still don't know how or why....and it didn't help me like the car any better.

 

Yes. It can be maddening. Further to the DA is the wind speed and direction. While 3rd gen F- bodies and Vettes are slippery by design, if there's a south east 20 MPH tailwind at my local track, I'm stoked. Much better than the prevailing northwest breeze that never seems to subside here on the high prairies.

 

DA is a real PITA. This is especially true with car development when changes from weekend to weekend make comparisons all but impossible sometimes. This is why I resort to corrected times.
Case in point: I know this new combination is faster on all metrics. The engine is more powerful than anything before, the transmission shifts like lightning (so far), it leaves harder and has better shift recovery with the new converter and new tires should be providing the necessary traction. (I say should because there's work to be done on the chassis side to get that 60' dialed in).
The thing is I can't produce a "personal best" time slip because the slower car ran 12.641 @ 106.82, 8.043 @ 85.73, 1.85 60’ in good air (as noted above with a 1300' DA) while the new combination went 12.88 @ 106 in 4000' air.
No time slip trophy to be had.
But corrected? Now I see the improvements. While the actual numbers are underwhelming, the corrected numbers are demonstrating those gains. Better by 2/10ths and nearly 3 MPH. That to me is a reinforcement of that development path. That is was right out of the box, never tested previously and no trackside tuning is even more encouraging. It's tempting me for a season ending last hurrah this weekend. If I wasn't so busy otherwise, I'd pack up and go.
Now, once I get the 60' sorted out and if the old adage is true as I've often found it to be, then a tenth in the 60 is worth two tenths at the stripe. I see no reason why this car can't run mid 1.6's. Then 11's would, or should, be attainable.
A lot of what I just wrote is repetition I know, but this is just reinforcing the point.
Mission Raceway on the west coast has a 25' elevation! At this very moment, albeit 7am on the coast, -322' !!
The forecast makes me want to go right now too.

 

If you run the same ET and Trap at 4000' as you ran at 1300'...that is a significant improvement. Agree that correcting helps you "See" it, better, though.

 

Interestingly, it did that for trap speed. 106 vs 106 uncorrected. 1300' vs 3900'. ET however was 2/10ths off. 12.64 vs 12.88. The 60' times were identical. 1.85.
So as far as top speed goes, which can be interpreted as HP, I'm ahead. Which in my case, is the whole point.
Faster. Better. Stronger. (or the 6 Million Dollar Man's blurb to that effect!)

 

Well technically, running the same speed at a higher DA than at a lower DA means the car is actually faster if you calculate to corrected altitude. It's like getting dyno numbers. A good dyno operator will give a sea level corrected result since at higher altitudes, you will perform worst. That way you can compare dyno numbers from a car that dynoed in Denver to a car that dynoed in Vancouver.

Stop making me drool about wanting to go to Mission. I could only dream about running in that kind of air.

I went to Yakima many years ago. It was something like 2700 feet DA. My engine sounded so much stronger and crisper than running at high altitude.

 

Exactly.
When I moved west from Ontario in 2014 I had the idea of first getting a time slip at my "home" track at Toronto Motorsports Park (which is nowhere near Toronto!). Then later that summer, after driving the car cross country, I'd go for another time slip at the new track then known as Castrol Raceway. The idea was to run 12's at both tracks. I laid down a new personal best in August 2014 with an uncorrected 12.6 @ 107 in Ontario. While I missed the season closer here in Alberta (it snowed in October and that was the end of the season) I managed to get to the track in April the next year. I couldn't break into the 12's! MPH was down to too but only by 1 MPH. I thought I had hurt something on the 3500 kms tour the previous summer. Again in June I tried and managed a couple of 12.9's at 104-105.
It was then that I started the DA correction and soon calculated that Ontario air netted a 12.46 @ 108.4 with it's 1300' DA. The really interesting part was that the slow Alberta times calculated to almost exactly the Ontario times. A couple of 12.48's @ 108-109. The 2210' DA played a big part. Now with this 10 years later run a week ago, nearly 4000' plays a bigger part still. And the correction demonstrates it's faster overall.
Overall though I'm satisfied to get that baseline and besides hoping for better air there are a few things that need addressing.

 

I'd be more than willing than to road trip it next summer. Load up your car and we can tandem across the mountains, race at Mission on Friday night and head back on the weekend. 11 hours.

 

Man....I'd be inclined to jump in on that....if Mission is at sea level?? EDIT: Just looked it up....25' elevation!!! Nice!

^TOTALLY!^
I grew up running my car ('83 TA's) at New England Dragway....88' above sea level. Then moved here, and started running at RMR at 4200' on 6000+ DA's. Then RMR closed. Waaa-Waaaaaaaaaa......(Debbie Downer sound)

I think that I could go something w/a 12 at the being of it, at sea level with my stock LT1. I sure would love to have a crack at that, but either coast is a long travel and haven't had a car-guy pal who's committed enough to make a thing of it.

 

A guy could dream about something beginning with an 11...

 

Denver was an interesting track for an NHRA race. It took a long time for ProStock to break 200 MPH when they were still running carbs. Test in Florida, 205 MPH. Go to Denver 198 MPH. Simply not enough air to make HP.

I guess I should get my butt in gear and start creating a new spreadsheet. It may be a long time before I ever get back to the track but I like the challenge of creating a new log book spread sheet.

So many things to do to go racing again.
Finish the transmission tunnel
Replace all the expired SFI components
New chassis certification
New competition license

Best guess to be race ready again would be around $2000 and without a local track, I would need to travel about 6 hours round trip every other week to have fun. Racing isn't as cheap as it was 20 years ago especially when we had a local track.

 

I can relate. It used to be a 2 hour one way to go racing back home. Now it's 20 minutes.
Your "to do" list is longer than mine (and certainly more expensive) as I've jumped through all of the hoops to actually race again after ten years. Those hoops cost of a lot of dough though.
If you ever do get back to the track (and I sincerely hope you do) I'll meet you there. Rad Raceway is close (and I could provide a sort of base camp if needed). Medicine Hat is almost 5 hours (one way) and Mission...well you know how far away Mission is. That however is still on my radar. As in Ontario.

 

In a stock C4? That IS a dream!

 

Actually, I was thinking more about my own heap.
I think all of the ingredients are there. If I can sort out the 60', even by a tenth or tenth and a half, then that should net an 11 second time slip. It's 12.22 corrected now with a 1.86. This chassis configuration has done 1.7.

 

I've raced at Medicine Hat and Edmonton back when it was Castrol Raceway. I've never been to Rimby even though it's only 1/8 mile.
Back when Calgary had a track, I was a 10 minute drive from the track. I'd go race Saturday night then just leave the car there in the trailer, go home and show back up at 8 AM when the gates opened. Even did a lot of Friday night Secret Street nights just to get some track time although on Friday nights, traction was poor at best. Still managed to power my way down the track on big slicks while street cars just spun off the line. Pretty bad when I would lose traction and coast to a 11 second 1/4 mile and still beat the street cars

In my early years of racing back when the car still had a 383, I was making 100 passes down the track a year. Finally broke into the 11's before exploding the engine. Those stock 400 rods and bolts and stock cast 350 pistons just didn't like going to 7000 rpm. Went BBC and never looked back although I broke a few of those also.

Current engine has nothing OEM except an alternator and that's not even from a third gen. Current engine is ready to go. No passes since it was last disassembled to be freshened up and that was years ago.

 

As mentioned above, the spreadsheets are a big help. I use a log book that summit racing sells for $6. I am on my second one now, as I used up one book to completion between 2020-2024 ! Datalogging is a huge help too, and despite my best efforts at it, I know I am leaving a whole bunch of performance on the table.
https://www.summitracing.com/parts/s...4aAootEALw_wcB


Once you can chop down that sixty foot, the E.T. will start falling by a few tenths.
I just read that your season is done up there at the track. Bummer! hit it hard next year

 

This is a call to, if it's possible, to get your car back to the track.
I'd love to see it in person.

 

Exactly that on the 60'. My PB was 1.7 flat long long ago. Best this year (and the last couple of times out 10 years ago) was 1.85.
If I can get that 1-1/2 tenths back (at the very least) then it's a big step forward at the big end. If the air is decent, that'll give me a real time slip that would be a personal best. The MPH seems to be taking car of itself. When you have the same trap speed in 4000' air as you did in 1300' air, it's saying something. That part was very encouraging.
Not sure how "hard" I'll hit it next year, but there's going to be several Friday race nights coming my way.