Gen V Drag Strip Results & C7 Corvette

Nine Ball

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I finally had an opportunity to take the new Viper to the drag strip, Royal Purple Raceway in Houston. I had read a few posts/feedback from others like JackB, who have taken their Gen 5 Vipers to the track, where it was mentioned that the clutch didn't like slipping off the line, and that burnouts could cause the car to go into reduced power mode. I experienced both, for myself.

My first pass was the best pass. I made 2 other clean passes later, but in reduced power mode. The car never felt fast the entire night, indicated by the lower than normal trap speeds. It just felt slow, all the way down the track. I've made a lot of hits in this car, out on the streets, and I can tell the difference right away if things feel off.

Details:

2013 SRT Viper w/ Track Pack
ESC and TCS off
5000 rpm launch (clutch roasted on this)
3505 lbs raceweight (driver 180 lbs)
DA = +650'
1.82 60'
7.44 @ 96.47 mph 1/8-mile
11.43 @ 124.34 mph 1/4-mile

http://youtu.be/J-fTB_krD_8

The other two passes, the car only trapped 122 and 120. As DA got better, the car ran slower. It was clear that something was holding back the power after that first burnout I made. It didn't seem to clear up until I was about 20 minutes into driving home, after some highway miles.

Some notes to share about the car, even though I only have 3 runs of experience with it.

-The clutch isn't ideal for drag racing. It reminds me of the stock Corvette Z06 clutch, light pedal pressure and does not like any sort of heat. Once the clutch gets hot, from trying to launch it, it will not disengage properly, and it will slip on the 2-3 shift. It also has the same heat related issues with the hydraulic system, causing the pedal to get spongy. Clamping force feels okay, but not the friction material. I may have someone upgrade my clutch disks to a ceramic/bronze puck arrangement, sort of like the Bad Boyz Garage clutch. Those clutches laugh at heat, and almost grab better when they are hot.

-First gear in this transmission is too tall. It is cool for magazine racers that they can get 0-60 in one gear, but it isn't good for drag racing. You need a lot of rpm to get this car off the line, assuming you have the tire traction. I tried dumping at 4600 rpm and the car bogged hard enough for me to abort one pass. The 5000 rpm dump worked, but my drag radials held better than the clutch did. That was with 31 psi in the tires! I was on 345/30-19 Nitto drag radials, so a similar to stock height tire. Running on stock tires would have been easier on the clutch, but also a trade-off in traction.

-We really need to figure out why these Gen 5 cars lose power after doing 1 dyno run, and apparently after doing burnouts. I had the ESC and TCS turned off each time, yet it still went into reduced power mode. This is unacceptable. I can't jump out of the car after doing a burnout and pull ECM wire harnesses, like SRT showed in their dyno video. What the hell is that all about?

-The car didn't like doing 2nd gear burnouts, even in the wet portion of the box. Brakes were too good, haha. It wouldn't put down enough torque to keep from stalling out. 1st gear burnouts worked like a charm, however.

-The car did show wheel-hop on the later two passes, but that is likely due to the track prep going away as the night went on. It was just a normal test & tune night. I lift when wheel-hop is felt, as that can cause damage to the rear. I blame that one on track prep though. Stock tires would have been worse, in that situation.

So, I learned a lot in 3 runs. Good for mental notes. I plan on trying it again during a track rental day on Nov 3, where I'll be able to get many more passes. I may opt to run on my street tires that day. It will take perfect weather, good track, and, and figuring out why the car goes into reduced power mode, before we see 10s out of these cars.

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As seen in the photos, there were two brand new 2014 Corvettes at the track. Although we never raced side by side, we did get some back to back runs. The automatic trans C7's are no joke at the dragstrip. The red C7 (Edit: has a custom dyno tune) ran an 11.73 @ 118 (1.74 60') right behind me. He later went 11.67, and then after a very long cool-down and pushing it into the water box, it clicked off an 11.47 @ 121, once the DA hit +250 around 11pm. That is a new record for C7s. I know the owner, the car is stock other than a tune, and is a non-Z51 base model automatic. There is something really cool about how they launch, the almost seem to have a higher stall converter on the initial bite, then once the car moves out a few feet, the converter locks up and the tires haze a tiny bit. It consistently cut 1.7 times on the stock tires, regardless of how the track prep went downhill. They are also geared perfectly for the 1/4-mile, hitting the top of 3rd gear at the finish line. The blue C7 (no custom tune) went 12.52 @ 118, spinning off the line. It later went 11.8 from what I was told. It appears GM did their homework with the automatic C7's. They are solid 11 second cars.

Tony
 
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Bobpantax

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Thank you very much for the excellent feedback. Would you guess that it is a calibration glitch causing the power loss? Since Jack experienced the identical phenomenon it seems like it would be. With respect to the clutch, I wonder if a stock Gen III clutch would work. I still have one in my car and although it is a much heavier pedal feel, it has never given me any problems despite my HP/Tq level..
 

hammerofgods

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If the base version of C7 yields these results at the track, what will the hi po variant do? Not sure which one is more surprising, Viper should be walking all over Corvette, regardless of auto or manual transmission. This is not a good news at all. Hopefully Chrysler can offer a retroactive power upgrade pack for Viper, time to crack the software open if the Viper wants to survive.
 
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Nine Ball

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If the base version of C7 yields these results at the track, what will the hi po variant do? Not sure which one is more surprising, Viper should be walking all over Corvette, regardless of auto or manual transmission. This is not a good news at all. Hopefully Chrysler can offer a retroactive power upgrade pack for Viper, time to crack the software open if the Viper wants to survive.

Thanks for your response Hammerofcaptainobvious. I think you thrive on negative Viper info. I'm just sharing the facts, you have nothing to contribute here.

Bobpantax said:
Thank you very much for the excellent feedback. Would you guess that it is a calibration glitch causing the power loss? Since Jack experienced the identical phenomenon it seems like it would be. With respect to the clutch, I wonder if a stock Gen III clutch would work. I still have one in my car and although it is a much heavier pedal feel, it has never given me any problems despite my HP/Tq level..

Sure would be nice if SRT engineers could respond, and tell us the magic secret to making dyno runs and doing burnouts. Reduced power mode is inexcusable. Tell us *********** it. As for the clutch, I'm okay with the aluminum flywheel and light pedal, as my '06 has a similar feel with the BBG clutch. That clutch has more aggressive pucks, and holds my 1100 rwhp no problem. Run after run after run. The '13 needs a material upgrade, if people want to drag race. I know a few clutch manufacturers, might look into developing replacement disks for the OEM clutch.
 

georgethedog

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Hi, Nine Ball. That is an excellent write-up. Thanks for the information. No matter the results, it had to be fun to drag it and then assess what happened. Yea, seems GM got some things right. What did you think of the looks of the Vette in person? There just are not any around where I live yet. Best of luck next time you go.
 

01viper4me

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Thanks for the information. This is quite disappointing primarily at the fact the Viper's computer puts it in nanny mode when you get on it. I know that the viper isn't designed to be a drag racing car; however, straight line acceleration is what most owners will actually use on a daily basis. Hopefully the codes will be released so current and potential owners can start tinkering with the engine and get more out of it.
That being said, the simple fact that a base automatic C7 is putting down an 11.45 is truly incredible. GM has really done a good job with this one. Very cool in my opinion to see the US bring top performing cars. A $60k Vette and a $100k Viper literally dominate the tracks against cars costing hundreds of thousands more. Amazing how our cars have progressed in just 14 years!
 
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Nine Ball

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Hi, Nine Ball. That is an excellent write-up. Thanks for the information. No matter the results, it had to be fun to drag it and then assess what happened. Yea, seems GM got some things right. What did you think of the looks of the Vette in person? There just are not any around where I live yet. Best of luck next time you go.

I like the Corvette, having owned two C6's myself. It looks modern and edgy, futuristic. General consensus based on the comments both cars got while parked side by side, the people "like" the C7, but they are in love with the Viper. The Viper still pulls the crowd, it is just a **** car with all the curves and wide body. But, it doesn't attract people any more than the older Vipers do, and doesn't stand out as "new" like the C7 does. That could be a major problem in selling them.
 

09 Venom

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Thanks for the info. I would concentrate on improving the Gen V's time and figuring out why she feels to have lost power. With all my years of drag racing it is not fair to compare an auto tranny to a manual. Even with launch control. I might have missed it but what was the temp. outside that night?
 

ViperSmith

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Very interesting.

It would be helpful if SRT engineering would speak up here and give us some insight to what is going on and how to overcome it.
 
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Nine Ball

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Thanks for the info. I would concentrate on improving the Gen V's time and figuring out why she feels to have lost power. With all my years of drag racing it is not fair to compare an auto tranny to a manual. Even with launch control. I might have missed it but what was the temp. outside that night?

Density Altitude was approx +650 ft above sea level, on my pass. Temps were around 72F at the time. Later on in the night, when the C7 ran the fastest pass, DA was around +250'. Good weather, not record-setting weather. Sometimes we get lucky enough to have negative sea level DA, but it is rare.
 

ferraritoviper

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Damn Tony, that sounds rather disheartening (reduced power mode and over heating clutch...this is supposed to be a race car right from the factory), especially for racers like you and JackB. Gotta figure out how to get a response from SRT on these matters, although they should have found these problems during all the testing they did before launch.

Don't count on them reading the VCA Gen V forum, after the bashing that's been happening here, coupled with the lack of VCA moderation and SRT's flight from the VCA. BTW, great post!!
 
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Nine Ball

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Very interesting.

It would be helpful if SRT engineering would speak up here and give us some insight to what is going on and how to overcome it.

If anyone reading this personally knows Dick Winkles, could they please phone or email him for the answer? Why were they pulling ECM wiring harnesses loose to make dyno runs on this video:

http://www.youtube.com/watch?v=ZrTyJXIyeEY

Everyone that has dynoed their '13 Viper has been only able to get one run, before limp mode kicks in. We need to have SRT answer this for us, tell us what to do/avoid/whatever.
 

jsd512

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Jeez. A C7 went 11.40s with just bolt-ons. Yikes. Nothing like it, seeing your dream car fall from grace. [Moderator edit: Please keep PG] . I'm sorry. :dunno:
 

Bobpantax

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From the video in the post above, I think it is safe to assume that SRT is aware of the issue and is working on a software patch to upload and correct whatever calibration issue is the cause of the power cut. ( I would guess there is a gremlin in the torque management.) The programming for the Gen V controller is even more complex than the Venom programming was for the Gen IV.

I have faith in SRT's ability to solve the problem soon. Software patches are not a new phenomenon. I think that many beginning year(s) performance cars have undergone same. No big deal.
 
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WANTED

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Great info for all the drag racers. i love drag racing to see what the car can do in the 1/4 mile stock. Very
disappointing what happens after one run, major problem as I see it. Something must be wrong in the programing
for this to happen. SRT needs to wake up by at the least offering a solution to this problem. As far as burnouts I
never do them with stock tires, only a slite spin of the tires to clean them off. Hate to say this but GM is way
ahead of getting the most out of the Vette not limiting what can be done with it, plus a stock Vette is kicking
butt at the strip. Hope you hear from SRT for a fix.
 
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Nine Ball

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Great info for all the drag racers. i love drag racing to see what the car can do in the 1/4 mile stock. Very
disappointing what happens after one run, major problem as I see it. Something must be wrong in the programing
for this to happen. SRT needs to wake up by at the least offering a solution to this problem. As far as burnouts I
never do them with stock tires, only a slite spin of the tires to clean them off. Hate to say this but GM is way
ahead of getting the most out of the Vette not limiting what can be done with it, plus a stock Vette is kicking
butt at the strip. Hope you hear from SRT for a fix.

I normally don't do long burnouts, either. But, this track was forcing everyone through the waterbox, no way to drive around it. Annoying... :)
 

ACRucrazy

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The red C7 had a 1.68 60ft. If you could have managed a 1.68 vs your 1.82 you would have been a 11.1 or better.
You also picked up 28mph vs the C7's 26mph on the back half.

He beat you in the 1/8 with his 7.40 vs your 7.44, however you made it up on the back half. If the Viper can get the launch down there would be no worries with that C7 as is. He had a great burn out and a great launch with that Auto.
 

FLL-B/W-GTS

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Very good post,Gen.5 Viper Very disappointing performance at drag strip.... I mean,pulling power after one run on a high performance car,Really SRT...
 

SnakeBitten

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SMH at SRT. Anyway I wonder how the mags got to do those low 11's at 128mph without this crazy glitch happening to them. I don't remember any of them complaining about this problem. Hopefully they will fix this for free for the owners in the near future. This car really needs some good press pronto.
 

BigDawg

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Great info and thanks for the videos. By any chance do you know what the '14 SRT Jeep ran? I've been itching to get mine to the track.
 

Solid Red 98

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I'd be curious to see if they've fixed this cpu problem on the 2014s. This is usually the sort of issue that companies would want to keep quiet and then fix in the next model year. But there's no question that the gen V isn't really set up for drag racing. But I say, owners here should try their best to get their feedback to SRT elsewhere as I doubt they look at these forums anymore for obvious reasons. SRT is a very small company that is definitely open to suggestions.
 

Bobpantax

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The assumption that SRT does not look at our forums is not correct. It is a normal part of the marketing function. There is value in knowing how and what we think about the Gen V and it helps detect any problems that might occur under unanticipated circumstances.
 

TrackAire

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I normally don't do long burnouts, either. But, this track was forcing everyone through the waterbox, no way to drive around it. Annoying... :)

I've posted this before, but the Gen 4 has a power cut off if you try to left foot brake and accelerate at the same time. I'm thinking that there is a glitch in the programming of the abs more than anything else and causing this power cutoff.

Tony, have you or Jack done any runs that did not include a burnout (which would replicate a "brake on" & "gas on" signal to the pcm?....pretty much what the dyno would do too, gas on but the front tires aren't moving so the computer is assuming the brakes are on)

Is there an ABS fuse to pull to try and disable the ABS for dyno runs? Couldn't hurt to try. I'm not sure I'd suggest disabling the ABS for the drag strip, but SRT needs to give some answers asap or somebody will start trying different "remedies" and possibly end up in an accident.

Regardless of the final ET's and pcm issues, looked like a great night to be at the drag strip having fun and enjoying the atmosphere.

Cheers,
George
 

ACRucrazy

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I have seen more than a handful of Gen V acceleration videos where it shows the brake lights coming on in between shifting. I don't know if I can chalk them all up as the driver tapping the brake as his shifting by accident. I wonder if its something else?

BTW, this is such a sweet picture!

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Nine Ball

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I've posted this before, but the Gen 4 has a power cut off if you try to left foot brake and accelerate at the same time. I'm thinking that there is a glitch in the programming of the abs more than anything else and causing this power cutoff.

Tony, have you or Jack done any runs that did not include a burnout (which would replicate a "brake on" & "gas on" signal to the pcm?....pretty much what the dyno would do too, gas on but the front tires aren't moving so the computer is assuming the brakes are on)

Is there an ABS fuse to pull to try and disable the ABS for dyno runs? Couldn't hurt to try. I'm not sure I'd suggest disabling the ABS for the drag strip, but SRT needs to give some answers asap or somebody will start trying different "remedies" and possibly end up in an accident.

Regardless of the final ET's and pcm issues, looked like a great night to be at the drag strip having fun and enjoying the atmosphere.

Cheers,
George

George, excellent post. We may be on to something, knowing that info about the Gen 4. I could see how the computer might not like the brake + accelerator. Might be as simple as disabling the brake light switch on the pedal, for track visits. I did not attempt any non-burnout runs, due to us having to drive through the waterbox. Out on the street, the car has zero issues taking off from a stop. I'm certain it is the burnout or dyno actions causing this low power, whenever rear wheels are spinning and fronts are not. Pulling the ABS fuse (if it exists) might also be an option, as you really wouldn't need it at the drag strip.

I have seen more than a handful of Gen V acceleration videos where it shows the brake lights coming on in between shifting.

Mine has done this. Some people even mentioned it happening last night. I swear my foot never touches the brake pedal during a shift, I even had my racing shoes on. I'm not even grazing the brake pedal, but my brake lights will flash sometimes during a shift. Thinking the clutch pedal might be making the brake light trigger, maybe a vibration? Weird. The pedals look identical to my Gen 3, and it never had that issue.
 
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Nine Ball

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SMH at SRT. Anyway I wonder how the mags got to do those low 11's at 128mph without this crazy glitch happening to them. I don't remember any of them complaining about this problem. Hopefully they will fix this for free for the owners in the near future. This car really needs some good press pronto.

Only 1 car has been tested at an actual strip, it was the white one on drag radials that went 11.1 @ 128. That was a manufacturer plate vehicle. The magazine guys typically do not use a drag strip, they just use GPS timers on private roads or pavement. That is another reason magazine times aren't that accurate.
 
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