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Hey guys,

Has anyone with a stage 2 RK Autowerks supercharger run at the drag strip? How much faster is it than a ESS SC kit with a 92mm pulley? Does the intercooler make a lot more horsepower?

I know Clemster's ran 11.7s, but most other supercharged M5's I've seen are slower. I've read somewhere that in the summer a blown M5 is not much faster than stock. Is tuning these cars for consistent performance an issue?

It seems very rare to see owners of supercharged M5's posting times. Is it due to disappointing performance? I have seen the 500+ whp dynos for various supercharged M5's on the board, but I thought they would be faster. Even a stock E55's on DR's run high 11's.

Thoughts?
 

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Hey guys,

Has anyone with a stage 2 RK Autowerks supercharger run at the drag strip? How much faster is it than a ESS SC kit with a 92mm pulley? Does the intercooler make a lot more horsepower?

I know Clemster's ran 11.7s, but most other supercharged M5's I've seen are slower. I've read somewhere that in the summer a blown M5 is not much faster than stock. Is tuning these cars for consistent performance an issue?

It seems very rare to see owners of supercharged M5's posting times. Is it due to disappointing performance? I have seen the 500+ whp dynos for various supercharged M5's on the board, but I thought they would be faster. Even a stock E55's on DR's run high 11's.

Thoughts?
First point; Clemster is a bad as* drag racer.; the car is wicked fast.
2nd; intercooling is awesome, the only better improvement is adding methanol. It WILL cool the intake temps, which will prevent the DME from pulling timing, which is the reason the cars loose power in the heat. I lost about 50 rwhp without an intercooler or meth. With meth, on the dyno, I gained 49 RWHP..

Just saying :M5launch:
 
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Has anyone with a stage 2 RK Autowerks supercharger run at the drag strip?
Not that were aware, I was the only one until late this summer, and I don't really drag race, I road race... Going in a straight line doesn't really do it for me...
How much faster is it than a ESS SC kit with a 92mm pulley?
Our stage 2 kit is ~611HP (9.5psi) and it's intercooled so the power will not be affected by heat soak, an ESS with 92mm can run lean (tune wasn't meant for 8psi) and really can only work with Meth...
Does the intercooler make a lot more horsepower?
Intercooler allows you to run more boost with a denser air charge and more timing safely, so yes it makes more power...
I know Clemster's ran 11.7s, but most other supercharged M5's I've seen are slower. I've read somewhere that in the summer a blown M5 is not much faster than stock. Is tuning these cars for consistent performance an issue?
What you're describing is heatsoak and it kills cars without charge cooling (intercooler, meth etc...). An air to air intercooler is the simplest most efficient and effective means of having repeatable power on the street. For glory runs on the drag strip an air to water is better as you can ice down the water and get the air sub ambient...
It seems very rare to see owners of supercharged M5's posting times. Is it due to disappointing performance? I have seen the 500+ whp dynos for various supercharged M5's on the board, but I thought they would be faster. Even a stock E55's on DR's run high 11's.
I think it's more horses for courses, some guys are into dragging, some guys aren't. comes down to traction with a 600HP RWD car. If you've got the inclination, it's simple physics, car is about 3900lbs, 611bhp (520 whp), plug it in to a drag calculator. I get 11.50's with 120mph trap speed from a computer, should be faster on the track!

We've got great specials going on right now if you wanna strap on one and be the first RK S2 in the books!
 

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Track conditions and density altitude will have a huge effect on results, even with IC and/or meth. Of course, driving skill plays a role as well. Drag racing might be dumb, but it sure isn't easy in a nearly two ton car with IRS. ;)

A S/C'd car without any intake cooling will quickly heat soak and disappoint. I always iced the plenum, discharge tube and Vortech between runs. Even so, on warmer days the car would come off strong and then lay down on the back eighth. I could feel it pull timing as the IAT's rose in mid-run. That's a bummer when you pulled a 1.7 60'. An IC or meth would likely remedy that issue.

My 11.7 runs were before I installed the methanol injection and I only had one occasion to run with meth on my home track. In back to back pulls I was .3 quicker and 3 mph faster without the meth. Too much fueling on a cool day? Not sure, but that's what it felt like. Your results may vary. :biggrin:
 

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Guesstimate low 11s with skilled driver and drag tires.
Honestly, I doubt that low 11's is attainable. Recently Jason from Buckhead went under my 11.72 with an [email protected] This was with ice water running through the A2W intercooler on an RMS kit running around 12 psi. Also, he was running on drag radials at Maryland International Raceway, which is about as good as it gets for putting down fast times. IMO, you'll need beefed internals to go much under mid 11's. And a bunch of skill. ;)
 

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Trap speed is what really counts, folks, and is most indicative of the car's power. Quarter mile times exemplify driver skill more than anything, which is why I want Adam to drag my car sometime!

--Peter
 

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Honestly, I doubt that low 11's is attainable. Recently Jason from Buckhead went under my 11.72 with an [email protected] This was with ice water running through the A2W intercooler on an RMS kit running around 12 psi. Also, he was running on drag radials at Maryland International Raceway, which is about as good as it gets for putting down fast times. IMO, you'll need beefed internals to go much under mid 11's. And a bunch of skill. ;)
hah, I count 11.4 low 11 :2:

and I do think it's possible, if you had those 50 HP more in your car you would get those 3 tenths in last half of the quarter when you get full traction :)
 

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Why obsess with 1/4 mile marks? A more usable metric is 60 to 130 time. Take 3 runs back to back to back, pick the median. It eliminate bad driver/launch and takes into consideration of heat soak. Anything under 10 sec is respectable, under 9 is fast, under 8 monster!
 
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Discussion Starter #11 (Edited)
We've got great specials going on right now if you wanna strap on one and be the first RK S2 in the books!
[/INDENT]
I've been on the fence for a while, but your kit is definitely the most sorted out in my opinion and would be my first choice.

In regards to heatsoak, is it fair to say that any supercharged e39 m5 will most likely run significantly slower on a hot day or after a couple of acceleration run without an intercooler or methanol injection? I remember watching an M5 with a VT550 kit on a dyno pull event and each consecutive run the WHP fell dramatically. Maybe 50 hp from 1st to final pull.

Track conditions and density altitude will have a huge effect on results, even with IC and/or meth. Of course, driving skill plays a role as well. Drag racing might be dumb, but it sure isn't easy in a nearly two ton car with IRS. ;)

A S/C'd car without any intake cooling will quickly heat soak and disappoint. I always iced the plenum, discharge tube and Vortech between runs. Even so, on warmer days the car would come off strong and then lay down on the back eighth. I could feel it pull timing as the IAT's rose in mid-run. That's a bummer when you pulled a 1.7 60'. An IC or meth would likely remedy that issue.

My 11.7 runs were before I installed the methanol injection and I only had one occasion to run with meth on my home track. In back to back pulls I was .3 quicker and 3 mph faster without the meth. Too much fueling on a cool day? Not sure, but that's what it felt like. Your results may vary. :biggrin:
Sounds like 11.7's are about as quick as a supercharged e39 will run for now? How much slower would you be with standard performance tires? The reason I ask is because I have a couple buddies with E55's and they destroy my M5 from any speed, especially from a dig. One is modded and has pulled a z06 from a roll. I was hoping to compete by adding a blower and showing them true M Power, but not sure it will be enough.

Do you happen to know how much rap the Buckhead M5 is producing?

Why obsess with 1/4 mile marks? A more usable metric is 60 to 130 time. Take 3 runs back to back to back, pick the median. It eliminate bad driver/launch and takes into consideration of heat soak. Anything under 10 sec is respectable, under 9 is fast, under 8 monster!
I agree with you there. I'm far from an expert in launching my car and most my buddies like to do a pull from a roll to eliminate launch variables. However, not too many e39 M5 drivers seem to post 60 to 130s as well. I believe Clemster posted a 9.xx sec time.



Thanks fellas for the input!
 

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In regards to heatsoak, is it fair to say that any supercharged e39 m5 will most likely run significantly slower on a hot day or after an lengthy acceleration run without an intercooler or methanol injection?

Sounds like 11.7's are about as quick as a supercharged e39 will run for now? How much slower would you be with standard performance tires? The reason I ask is because I have a couple buddies with E55's and they destroy my M5 from any speed, especially from a dig. One is modded and has pulled a z06 from a roll. I was hoping to compete by adding a blower and showing them true M Power, but not sure it will be enough.

Do you happen to know how much rap the Buckhead M5 is producing?




I agree with you there. I'm far from an expert in launching my car. However, not too many e39 M5 drivers seem to post 60 to 130s as well. I believe Clemster posted a 9.xx sec time.

Thanks fellas for the input!

Yes to the heatsoak question.

I'm sure there are other cars/drivers out that are capable of running better times than I did. I do think mine was running pretty well for a stock car with just an ESS 92mm setup and 3.45 gears. I'm sure there are others that can drive better as well. Not enough people have tried.

I race with many E55's and they are freight trains. They seem to launch effortlessly and make massive torque across the board. You'll need more than an bolt on kit to compete with anything more than a stock one. I know this first hand.

Hard to say, but I suspect the BIP car was making 550+whp

I did some VBOX runs at the track and on a 11.9x pass, these were my numbers.

0-60 3.6 sec
0-100 8.6
60-130 9.8

I never got data from an 11.7 pass but probably would shave a .10 or so off the first two numbers. My 60-130 isn't great as I have to shift to 5th at 123mph and I lose serious momentum.
 
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Why obsess with 1/4 mile marks? A more usable metric is 60 to 130 time. Take 3 runs back to back to back, pick the median. It eliminate bad driver/launch and takes into consideration of heat soak. Anything under 10 sec is respectable, under 9 is fast, under 8 monster!
-mid 9s with a stage 1
-8.8 when i had a stage 2
-7.9 with my V1 maxed out

i should be in the 6s by now, maybe even the 5s. The 2 shifts are what really hurt my times. But with gearing, its something im stuck with.

-R

Edit-I'll try and dig up the graphs too.
 
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