I went to dyno my SRT-6 today and the damn thing would hit the rev limiter at 4800rpms every time in 3rd and 4th gear with traction control(button) turned off. I then called up someone that has dynoed these cars before and was told to pull fuses 17&18 which I did and it still would hit the rev limiter at 4800rpms..................which PISSED ME OFF. I've never had a car before that you cannot dyno...........and neither had the guy that ran the dyno. I did get some good numbers and AFRs for up to 4800 though.............peak rwhp was 311 and peak torque was 379 with a 10.6 AFR. I'm happy with that part since my only power mod is SL55 complete intake with K&N drop ins and LET phenolic intake spacers. Ohh; it was on a dynojet dyno as well.

 

Wow, 379 tq seems real high for just having an intake and spacers. You must have a factory freak there.

 

I think it might very well be. I was talking to a guy at the track last night and he has a bone stock SRT-6 and could only run 13.7 out here in vegas. Granted he did have 100-150 lbs on me which would put it at a 13.6-13.55 with me driving as opposed to my 12.8 runs with just intake and spacers.

 

13.6 is a slow run for any srt6 imo. I ran 13.7 once because I slid down the first 10 or 15 feet of the track then bogged a lil. I ran a 12.8 too but the track I was (MIR) is almost at sea level. Granted my launch tecnique was'nt the greatest (mash the gas and go), but I was happy just being in the 12's with the same mods as you.

 

Exactly.............sea level and "vegas level" are two different worlds. A car that runs 13.4 out here in vegas will run 12.9 at sea level. If I corrected my times from last night that would put my car at about 12.3 which isn't too shabby.

 

turbocharged & supercharged cars do not suffer as badly from higher elevations as normally aspirated cars do.

 

That's a nice myth.............but untrue. I've seen the differences time and time again and have proven it as well. My Charger is N/A and I ran 13.5 bone stock at 2200ft above sea level..............many other Charger owners are running 12.9-13.1 bone stock at sea level. My buddy has a turbo'd GTP and at sea level he ran 11.95.................out here at 2200ft he ran 12.3x. Those are two of the countless examples of the differences in times that elevation/DA make on cars. There are cars that come out here from so cal and run every now and then and they are always wondering what's wrong with their cars and why they run so slow.....................high elevation and bone dry HOT air.

 

There are more threads on dyno'ing this car than there are threads in your sweater.
Do a search and you may find how to dyno it.
One method is to raise the front of the car and spin the front wheels, faster than 15mph I think, and that fools the car into thinking it's moving so it revs all the way.

 

Actually, the NHRA correction factors for TC and SC cars is 1/2 of that of NA cars.

 

Another thing to try (if you happen to have free time at the dyno) is to disconnect just the Yaw sensor and see what the car does. If it goes past the 4800 RPM mark, then it disables the ESP and allows a full RPM run. We have all have our solution. If not... nothing lost.

The only reason I had a full pull was because I was on a AWD (all whee drive) dyno that had the rollers linked. I also got kinda low numbers and I think it's because of the extra rotating mass.

Cheers!

 

Why were you counting the threads in my sweater?


It was impossible for me to spin the front tires since the dyno I used was an "in ground" and the front of the car was strapped down using the wheels.

 

Interesting to know the NHRA guidelines...................but I base my estimates off of real world numbers from my cars and people that I know which have the slips to prove it. There are soooo many factors and different cars and configurations that there's no ONE rule to cover all 100%. The easiest way to prove what I mean is to run your car(s) wherever you guys(at or near sea level) live..............then make a road trip out here to wonderful Las Vegas and do a couple passes to see how much slower you will run.

 

Regarding threads in your sweater - it was a joke - obviously lost on you.
Regarding spinning the front wheel, you obviously didn't do a search regarding this issue - you have to jack the car up before you can spin the wheel - I though this was obvious - obviously not!!!

1. Before jacking the car up, make sure it has stopped moving.
2. Ensure the car is in the correct position prior to jacking up (i.e. on the dyno).
3. Strap the car down.

Let me know if you need any more instructions!!!

 

By jacking the car up do you mean punching it and abusing it?

 

Yeah, preferably with a .38 special - just the right size!!!

 

Interesting to see this topic rear its ugly head again. How long have we been dealing with it, 3 1/2 years ?

 

Ok, try basing this estimate:

I have over 200 slips with this supercharged car, and the correction factors work tremendously well in assisting with my run predictions, down to the hundredth. My 18-plus years of competitive drag racing has given me a pretty good handle on what asmospheric and elevation corrections can make. These are then used in bracket racing. To make money.

I'm telling you that the NHRA correction factors are suprisingly accurate. I can't say the same for "people you know." I'm sure they're great folks, but physics is physics.

I could easily, using NHRA correction factors, tell you what your Las Vegas car will run in Chicago. Accurately.

Your dismissive approach of hard numbers is disappointing for someone looking for HARD NUMBERS on a dyno. As soon as those correction factors (SAE, anyone?) are there to help, I bet you're right there.

BTW, there is "ONE rule to cover all 100%" as you put it. It's called DENSITY ALTITUDE.

 

I know the sweater thread counting was a joke............maybe I'll put a laughing smiley next time so it doesn't get lost on you.


As far as jacking the car up and putting it on stands and then strapping it down to dyno..............that will NEVER be done on my car. I appreciate your informing me to make sure the car stops moving before jacking it up because I had a hell of a time putting it on stands last time to do the oil change while driving down the street. Silly me.

I need no further instructions from you................but thanks for asking.

 

Cool; I only have about 150 combined passes in my N/A V8, N/A V6, S/C V6 and Turbo 4 bangers. I have always preached about the negative and positive effects of elevation and DA and nobody seemed to listen..............then the one thread that I don't mention it I get a response like yours. I'm not dismissing hard numbers I was mentioning hard numbers from the beginning. I have a N/A V8 car that runs .5 slower at my altitude/DA than the same exact car at sea level. I also had a turbo 4 banger that ran .4-.5 slower here than at sea level. I now race my S/C V6 car which runs .3-.5 slower than those at sea level. Those are my HARD NUMBERS that I based my theory of all cars(n/a, s/c and turbo)having the same basic variations in trap/ET from sea level with perfect conditions to las vegas level with hot dry air. Maybe I'm not typing my explaination(sp) out correctly for others to understand. Ohh well...........you know what they say "pobody's nerfect".

 

So, I am still the only one to get a real dyno without spinning the front wheel? Lol, thats funny. And you don't have a factory freak, those dyno's read higher than other dynos, best way to see what kind of power your car makes is by trap speed, less variables, no matter how crappy you drive trap speed always end up pretty equal.