Went drag racing

[Ram x 10]

I took my '05 RC out earlier this evening for a test n tune 1/4 mile. I made 9 passes, 3 at a time with maybe a 40 min cool down in between. Air temp was 80-75 deg and humid, I forgot to snapshot the weather.....it was muggy! I should've brought some fans and/or a cooler of ice to aid in chilling out.

Setup as follows-

-General Grabber UHP tires.
-American Racing long tube headers, no cats, Magnaflow exhaust.
-BBK throttle body.
-SCT tune by Torrie.
-170 deg t-stat.

First pass out (my first 1/4 pass in many years), I nuked the tires for what seemed like almost an 1/8 mile and got out of it- ran an 18 sec at 75mph. Oy. Hot lapped and ran a 13.2 @ 108mph with a 2.1 60', then a 13.1 @ 108mph.

Let it cool down and dropped the rear tire pressure to 30psi. Headed back out and ran a 13.01 @ 108mph, followed by an embarrassing 13.8 (nuked the tires again running next to a Demon), then ran another 13.1.

Final time out I really tried to resist the urge to pop the clutch and mash the gas and managed to squeak out a 12.91 @ 109mph with a 2.0 60', got all pumped for breaking the 12 sec barrier and fried the tires on the follow up run to the tune of 14.1. Final pass ended up being 12.84 @ 109mph with a 2.0 60'.

I had a blast, it barks the tires in all four shifts! Next time out I'd like to have drag radials, maybe a new clutch with Viper hydraulics, and something to help with wheelhop. 40 or 50 deg air wouldn't be bad either!

 

[rottenronnie]

What track were you racing at?

 

[Ram x 10]

Lapeer International Dragway.

 

[rottenronnie]

Nice!

 

[Scotty_R8]

very nice

 

[Shaggy]

I took my '05 RC out earlier this evening for a test n tune 1/4 mile. I made 9 passes, 3 at a time with maybe a 40 min cool down in between. Air temp was 80-75 deg and humid, I forgot to snapshot the weather.....it was muggy! I should've brought some fans and/or a cooler of ice to aid in chilling out.

Setup as follows-

-General Grabber UHP tires.
-American Racing long tube headers, no cats, Magnaflow exhaust.
-BBK throttle body.
-SCT tune by Torrie.
-170 deg t-stat.

First pass out (my first 1/4 pass in many years), I nuked the tires for what seemed like almost an 1/8 mile and got out of it- ran an 18 sec at 75mph. Oy. Hot lapped and ran a 13.2 @ 108mph with a 2.1 60', then a 13.1 @ 108mph.

Let it cool down and dropped the rear tire pressure to 30psi. Headed back out and ran a 13.01 @ 108mph, followed by an embarrassing 13.8 (nuked the tires again running next to a Demon), then ran another 13.1.

Final time out I really tried to resist the urge to pop the clutch and mash the gas and managed to squeak out a 12.91 @ 109mph with a 2.0 60', got all pumped for breaking the 12 sec barrier and fried the tires on the follow up run to the tune of 14.1. Final pass ended up being 12.84 @ 109mph with a 2.0 60'.

I had a blast, it barks the tires in all four shifts! Next time out I'd like to have drag radials, maybe a new clutch with Viper hydraulics, and something to help with wheelhop. 40 or 50 deg air wouldn't be bad either!
View attachment 63144

Got any pics of you at the line or going down the strip?

 

[rottenronnie]

Sadly our nearest low-elevation track is 1000 km away (620 miles). What a difference that makes!

Normally, for each 1/10th you can shave off your 60 foot, it lowers your ET by 2 tenths (on a 1/4 mile pass).
Example 13. 2 with a 2.1 60 foot =
13.0 with a 2.0 60 foot.

 

[Ram x 10]

Got any pics of you at the line or going down the strip?

Aside of a grainy video from the last half of the track (during the 13.01 run) no pics from the track.

Sadly our nearest low-elevation track is 1000 km away (620 miles). What a difference that makes!

Ya gotta bring more "atmosphere" to those high altitudes. I've read a 20lb bottle of pressurized goodness really helps.

Lapeer is at 837 feet. I found a website that has previous weather observations and punched that into a density alt calculator. The DA around the time I ran the 12.8 was ~1900'.

That same calculator corrected my 12.84 to a 12.4-12.5. .4 off of that if I can get a 1.8 60' time....11.9s possible with weight reduction?

 

[rottenronnie]

I've seen many NA vehicles drop a full second from altitude to sea level. VERY few people seem to "get it".
Trackhawks run 12.50s here and 11.7/11.8 at sea level.
Negative DA at a sea level track helps even more.
I'm running low 12s at 3300 feet, so a sea level pass would be a treat!!

 

[Ram x 10]

Having driven a few vehicles up in the mountains of Colorado, I know first hand how altitude neuters performance (both internal combustion engines and myself). Ha!

Do the turbocharged vehicles run near sea level times at your track?

 

[rottenronnie]

Supercharged vehicles (like the Trackhawks) and turbocharged vehicles suffer less than a naturally aspirated engine.
And, large engines suffer more than smaller ones.
If Trainman brought his truck up our way for example, it would very likely run a low 12 or maybe a 12 flat. Certainly not 11.2s. That's just the way it is.
When we had NHRA class-cars up here years ago, they'd be WAY off there sea-level times.
You just do not see any 1/4 mile records falling at those higher elevation tracks.
If you really want to witness a difference, come up to one of our famous 7000 foot DAs and try running the sea-level numbers!!

 

[rottenronnie]

NO, Turbocharged vehicles do not run sea-level times up here.

The only thing that can is a Tesla.

NA vehicles lose 3.5% of their total horsepower for every 1000 feet they climb. So, 10% is lost on a good day here.
But, that's the key: On a GOOD air day.

It is rarely that here and I'd say an average DA in Calgary is 55-5800 feet on a decent summer evening; so power losses are substantial.

A guesstimate on performance losses for the forced induction engines might be 20-25% less than an NA engine. There are mitigating factors.

 

[rottenronnie]

It would be nice if we could keep shaving the 60 foot to lower ETs, but at some point (like running 11.9s as you indicated), you would need a substantial weight loss, lower your truck to reduce drag, run front skinnies for the same reason/rolling resistance and/or produce more power.

Have fun!

 

[VIPR PWR]

NO, Turbocharged vehicles do not run sea-level times up here.

The only thing that can is a Tesla.

NA vehicles lose 3.5% of their total horsepower for every 1000 feet they climb. So, 10% is lost on a good day here.
But, that's the key: On a GOOD air day.

It is rarely that here and I'd say an average DA in Calgary is 55-5800 feet on a decent summer evening; so power losses are substantial.

A guesstimate on performance losses for the forced induction engines might be 20-25% less than an NA engine. There are mitigating factors.

altitude can make a huge difference... leaning out or richening the fuel mixtures ... years ago in my 340 cid duster .. I lived in Las Vegas ,, went up mount Charleston and wow as I got higher up the car started running like crap ... luckily I had a Holley 780 cfm with vacuum secondaries that I had modified with external adjustable jets .. I actually stopped and played with the adjustment and got it running stronger ... i new about the altitude problem and new that’s what was happening ... had to readjust the jets on the way down lol fun times in those days ..
Vegas is at 2500 ft above sea level already .. not sure what mount Charleston is ,, but it is a snow capped mountain in the middle of the dessert ...

 

[rottenronnie]

That brings back memories. I also used an external kit for changing front primary jetting with the Holleys' that had a metering block.

Changing jetting helped to put the A/F mixture back in balance when climbing up, or going down in altitude.

But, there is just no substitute for the increased air pressure and oxygen provided at low altitudes.
Any of the supercharger kits installed at our altitude fail to produce the advertised boost. Typically, they are down nearly 3 psi. So, a 10 psi blower provided 7 psi here, etc.

 

[Trainman]

Supercharged vehicles (like the Trackhawks) and turbocharged vehicles suffer less than a naturally aspirated engine.
And, large engines suffer more than smaller ones.
If Trainman brought his truck up our way for example, it would very likely run a low 12 or maybe a 12 flat. Certainly not 11.2s. That's just the way it is.
When we had NHRA class-cars up here years ago, they'd be WAY off there sea-level times.
You just do not see any 1/4 mile records falling at those higher elevation tracks.
If you really want to witness a difference, come up to one of our famous 7000 foot DAs and try running the sea-level numbers!!

Hey Ronnie, Trainman here, thanks for thinking of me, we haven't talked in a long time. I still have the SRT-10, still NA, no new changes, but I have been having arm troubles, (my right arm, 50 years of fastpitch softball probably has a little effect), I will be 74 on my next birthday. I hope to get the truck out on Feb 23, 2020 at the next test and tune. Still have the CTSV, installing a new Kong 2650 supercharger. Still restoring the 73 SD-455 Formula. Still working on the 2000 Firehawk. And the 64 GTO is waiting. Bought my oldest daughter a 2019 Hellcat Challenger 6-speed manual for her birthday in Aug 2019....her first pass in her life she managed an 11.98 @ 120.87...so proud, I had just had surgery on Dec. 9 and could not drive any of mine. I need to get back on this site more often. PM me your phone and we can talk soon. Thanks again for the mention. Thinking of you guys. I reall need to iron out the launch on the SRT and get it in the high tens by this summer.

, Long time coming but here is the last video

 

[rottenronnie]

Glad you are enjoying life (and dealing with whatever it throws at you). Not much racing going on up here right now (-30 degrees) and too much snow!
My buddy just bought a Demon Hellcat (no point in racing that) but he won't be able to try it out around here until May unless it is towed south.
Hoping for some 11.7 or 11.6x with my own truck with the new drag radials this year. We will see how that goes.

Take care Mr. Miller!