e39 M5 v Corvette C5

[HarcoM5]

this was on the way home from work. I was stuck behind some slow driving old lady at a red light and the corvette was lined up next to her. I saw the corvette but didnt think anything of it as people in corvettes around here tend to be middle aged rednecks who dont want to race a bimmer and dont know what an m5 is. When the light turned green the guy in the corvette floored it and took off so now i am thinking that maybe i can get this guy to race me and better yet at high speeds.

So i patiently wait for someone's grandmother to get out of my way and as soon as the gap opens up next to me i take it and chase down the corvette. So i finally get up next to him and we are just cruising down the highway going 65ish or so. At first he really doesnt seem like he is going to race me so I'm a little frustrated since i put in all that time and effort and gas to just catch up to the guy. He was in a black c5 corvette convertible with dark tinted windows so i cant even see if he notices that i am willing and able. We come up on some traffic and he takes off and weaves in and out of it to get to the front. I think he saw me doing the same and finally decided to give it a go, probably thinking he was going to dominate me. So finally i get up next to him and drop it in third, we are already going 70, and he hears my exhaust pick up and he downshifts and takes off. I knew we werent going to do the customary 3 honk and go so i was waiting for him to just take off. The second i hear his engine pick up i mash on the gas. We race all the way to 120, as i am now well into 4th gear, and then shut it down. I maybe had a .5 CL lead on him when we shut down.

I think this upset him a little bit because now he is driving past me and slowing down and reving his engine up like he is ready to go and this time he means business. So i drop down to third and decide i will return the favor of getting the jump on him. So i do and we go to about 110 before shutting it down and it was about the same result.

I am not suprised at all that my 400hp car can beat his 350 hp car in a race at higher speeds. The higher speeds helps negate my weight disadvantage. My brother has a ls1 GTO, so it has the same engine as this corvette and i own him on the regular basis.

My mods are an exhaust system and custom made ram air intake system similar to the one AA offers.

I want to get the DME flashed but dont want to take the risk of the 7400rpm redline the shark injector forces you to live with and dont want the hassle of pulling out my DME and mailing it off.

[335e92tx]

Hmm.. good kill. I would think the LS was a little tired. Figure they are about the same hp to weight as you (~11 lbs per hp) but with better aerodynamics.

[S8ER01Z]

Nice kill..

Originally Posted by 335e92tx

Hmm.. good kill. I would think the LS was a little tired. Figure they are about the same hp to weight as you (~11 lbs per hp) but with better aerodynamics.

If you use GMs junk ratings that would be true....(actually using factory racings I still show them at 9.4lbs per hp with 345hp and 9.2 with 350hp).

Using RWHP numbers you will find the 345/350 numbers to be a bit low but regardless it's no where near 11lbs per hp. My heavy F-body is 9.8 using a 350hp rating.

[Jofu]

Don't M5's have better gearing? Wouldn't that totally explain the outcome?


Geoff

[m3chaser]

I imagine that if you raced a FRC or Coupe version it would have been even. The verts are a little heavier as always. Great kill especially since he got the jump on you.

[335e92tx]

Originally Posted by S8ER01Z

Nice kill..




If you use GMs junk ratings that would be true....(actually using factory racings I still show them at 9.4lbs per hp with 345hp and 9.2 with 350hp).

Using RWHP numbers you will find the 345/350 numbers to be a bit low but regardless it's no where near 11lbs per hp. My heavy F-body is 9.8 using a 350hp rating.

No reason to reference advertised numbers - to widely varying.
Figure early c5s were right about 300 stock right? And weight close to 3300? Sure sounds like 11 to 1 to me.

Regardless, it sounds like your saying it should be better than 11 to 1 for the c5 and since at best a e60 is 345 dynojet (maybe 355 with those mods), IT is right at about 11 so the c5 SHOULD have performed better.

Sounds like this thread seems to be saying 300 is not uncommon.
http://forums.corvetteforum.com/c5-g...o-dynojet.html

[m3chaser]

Originally Posted by 335e92tx

No reason to reference advertised numbers - to widely varying.
Figure early c5s were right about 300 stock right? And weight close to 3300? Sure sounds like 11 to 1 to me.

300rwhp at least, but the weight you referenced is off I believe. My brother has had his C5 on the scales and has heavier rims and still weighed in at 3150lbs.

[335e92tx]

I stand corrected - ~10.5 to 1 for a HTc5 (I won't quibble over 5 percent). Weight on the C5 is about 3200-3250 I think. (c6s are closer to 33).
And according to GM, the Z06 is the 3150lb vette.
By the same token, its tricky using track scales for weights. I tend to stick to verified standard practices. Like CD provides.
http://www.caranddriver.com/features...orvette_page_5 Curb weight: 3250 lb
http://www.caranddriver.com/var/ezfl...670cdc8527.pdf Curb weight 3126 lb
However, using that same source, it seems to indicate performance is just about identical with a c5 (m6). Low 13s at about 109 (which is better than ANY LS1 GTO mind you), even though weight is closer to 4000. http://www.caranddriver.com/var/ezfl...41fc2d331e.pdf
Gearing? Almost identical with a Manual c5. http://www.caranddriver.com/var/ezfl...31a61a9f68.pdf Yes, you will see faster with individual experiences. That is not unexpected.

[S8ER01Z]

Originally Posted by 335e92tx

I stand corrected - ~10.5 to 1 for a HTc5 (I won't quibble over 5 percent). Weight on the C5 is about 3200-3250 I think. (c6s are closer to 33).
And according to GM, the Z06 is the 3150lb vette. By the same token, its tricky using track scales for weights. I tend to stick to verified standard practices. Like CD provides.
http://www.caranddriver.com/features...orvette_page_5 Curb weight: 3250 lb
http://www.caranddriver.com/var/ezfl...670cdc8527.pdf Curb weight 3126 lb

Yeah it can get tricky to calculate...and that's my bad...didn't realize you were going off rwhp to begin with (which IMHO is the best way)...I see too many people doing it the other way which is what prompted me to post. My bad.


As far as rwhp my 01 has a curb of 3440 (verified on a cat scale but still the rated curb) and I put down 322rwhp/341rwtrq with the bottom of my airbox cutout (literally that was it...still through a paperfilter). Dynos vary so if you really wanted to skew things you could use a mustang dyno for one and a dynojet for the other (depending on who you want to have the handicap). Anyways..that was my point I guess... gearing could have made all the difference (not sure how fast an M5 is) but until you hit some serious triple digit speeds I don't see a gearing advantage kicking right away (unless those M5s trap much higher than I thought?). Regardless I wasn't saying the kill didn't happen or anything like that..just pointing out that it's hard to use GMs HP ratings for the LS1 cars since they obviously just made them up as they went along but you were already accounting for that.

[335e92tx]

I won't disagree there. I never use MFR ratings for much of anything. Having seen how much variation there is with weight, I doubt that output would be much less skewed. I tend to go with an average of dynojet numbers for output. Tends to nullify imaginative correction factors.
I tend to think the comparison between the holden and the M5 would be pretty representative of a 5.7GTO and a e60 http://www.caranddriver.com/reviews/...mparison_tests
So the vette should be at least .5 second faster.

[S8ER01Z]

Originally Posted by 335e92tx

I won't disagree there. I never use MFR ratings for much of anything. Having seen how much variation there is with weight, I doubt that output would be much less skewed. I tend to go with an average of dynojet numbers for output. Tends to nullify imaginative correction factors.

Yeah.. your good. I always end up painting you as a target for some reason...

[savage217]

Guy should have gotten a z06. The base models are no slouch but the c5 z06's are pretty cheap now a days. Nice kill.

[slomofo]

i love pushrod v-8's and all but this forum always surprises me at how many LS fans there are in here. they should have and LS sub-forum in bimmerforums

with that said, nice kill. all this speculation over rear wheel horsepower and we don't know what year, what mods if any, what gears, blah blah blah. stop couch racing, it's speculative at best.

[335e92tx]

Originally Posted by S8ER01Z

Yeah.. your good. I always end up painting you as a target for some reason...

Probably my user ID

Originally Posted by slomofo

with that said, nice kill. all this speculation over rear wheel horsepower and we don't know what year, what mods if any, what gears, blah blah blah. stop couch racing, it's speculative at best.

Probably true. But the OP opened the door for that didn't he?

I am not suprised at all that my 400hp car can beat his 350 hp car in a race at higher speeds. The higher speeds helps negate my weight disadvantage. My brother has a ls1 GTO, so it has the same engine as this corvette and i own him on the regular basis.

[HarcoM5]

My number of 350hp for his car comes from the fact that if he wasnt stock he should have beaten me.

My car dynoed at 355hp, the torque was a round 320 but i think a tad bit lower ,like 318 or 319. Which is usually on the high side for what fellow m5 owners are getting these days (our cars are pushing 10 years old). My car has 44xxx miles on it now and had 37xxx back when it was dynoed, so my engine is much younger than average these days.

A guy on m5board.com just dragged his basically stock m5, exhaust and shark injector which nets him maybe a 10 hp gain, and ran a 12.94 @ 107.xx and his 60ft were like 2.1s so nothing crazy to talk about there. I believe my car could run in that same range.

[Nik1703]

Nice kill. I'm also going to throw in a vote for that LS engine being a little tired. There's a fair number of base corvettes out there that aren't maintained. The 50hp difference is more then offset by your weight disadvantage.

[bigbeansm3]

too much magazine racing ITT

[Clemster]

Originally Posted by HarcoM5

A guy on m5board.com just dragged his basically stock m5, exhaust and shark injector which nets him maybe a 10 hp gain, and ran a 12.94 @ 107.xx and his 60ft were like 2.1s so nothing crazy to talk about there. I believe my car could run in that same range.

Hey, easy there on my 60' times. I did manage a 1.98 on my crappy Nexen tires on my best run of 12.92 @ 107.94. I trapped over 108 on a couple of passes. Unfortunately, I have no idea how I match up against a C5 vette. I'm on my way out the door to a meeting. Maybe I'll chase one down.

[m3chaser]

Originally Posted by Clemster

Hey, easy there on my 60' times. I did manage a 1.98 on my crappy Nexen tires on my best run of 12.92 @ 107.94. I trapped over 108 on a couple of passes. Unfortunately, I have no idea how I match up against a C5 vette. I'm on my way out the door to a meeting. Maybe I'll chase one down.

I believe that a well driven C5 will trap the same as your car with a similar ET.

[HarcoM5]

Clemster my apologizes for the misquoted 60 ft time. 1.98 is a lot better than 2.1 but i have still seen 1.8s from m5s. I'm not saying that i could run my car or any car for that matter fwith a 60 ft time faster than you. You are making us m5 owners proud with the 12.92 1/4 mile time. All you need to do is throw some drag radials on that bad boy and do an actual launch!

And as for matching up with a c5 corvette, as long as it isnt Gray Ghost C5's corvette or a z06 you should be in business. The higher the speed you start from is the better you will pull on him i think.

Nik1703, there is definitely a lot of base c5 corvettes out there that arent being maintained. But since the guy ended up looking middle aged (after we raced i got in the lane in front of him and could actually see a silhouette and his face with some detail) and had a custom license plate, i am thinking if there was a corvette that was maintained it would be that one. Granted he could be a 2nd owner but you would think if he was that he did the research on the car to make sure it was maintained well.

[S8ER01Z]

Originally Posted by m3chaser

I believe that a well driven C5 will trap the same as your car with a similar ET.

Unless you catch a 'really' well driven one... GMHTP went 12.7 @ 111mph in a bone stock manual C5.

http://www.gmhightechperformance.com...ure/index.html

[OMGWTFBODY]

Perfectly realistic outcome.

[Gray Ghost C5]

Good kill. Sounds like a good match between the M5 and C5 (weight and power) for a rolling start. I'm sure the Corvette driver was like, "What the F&@K?!?" He should have given you a thumbs up.

[HarcoM5]

well it was closer to 12.8 than 12.7. But i find it interesting that that site quotes the c5 corvette having 375 ft-lb of torque. I thought the ls1 was 350hp/250torque. Maybe even only 345 hp.

But i dont doubt at all that the c5 is going to run a quicker standing 1/4 mile. the m5 is a 4000 lb tank and the corvette weights 3200 (i think the convertible is a 100 lb heavier). Granted that my aftermarket exhaust as well as some other things i have done cut off a decent amount of weight.

[Clemster]

Originally Posted by HarcoM5

Clemster my apologizes for the misquoted 60 ft time. 1.98 is a lot better than 2.1 but i have still seen 1.8s from m5s. I'm not saying that i could run my car or any car for that matter fwith a 60 ft time faster than you. You are making us m5 owners proud with the 12.92 1/4 mile time. All you need to do is throw some drag radials on that bad boy and do an actual launch!

And as for matching up with a c5 corvette, as long as it isnt Gray Ghost C5's corvette or a z06 you should be in business. The higher the speed you start from is the better you will pull on him i think.

No apologies necessary. With some stickier rubber, I'm sure 1.8 is very possible. Hey, you should come on down to MIR on Dec. 5th for the next private track rental. They are a blast and the only way to go for some good heads-up racing on a well prepped track. Only a few dozen cars, mostly AMG's, BMW's and a few GTR's and Z06's. Maybe we can get a "regular" vette or two to show up.

I'm going to try to rustle up some drag radials for my next runs. My new OEM clutch will not like that. At all.