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My first 2 runs down the 1320 in the Vette

 
Old 11-04-2018, 07:05 AM
  #21  
Joe_G
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Thanks for chiming in James...great advice.

Huncie you might want to check out Fartpipe’s ZR1 thread and check out the log analysis and the videos.

https://www.corvetteforum.com/forums...r1-w-dr-s.html

and Fartpipe’s max effort 10.2 pass

https://www.corvetteforum.com/forums...135-35mph.html

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Old 11-04-2018, 12:23 PM
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Awesome, thanks!

James- those videos were the first time out on the MT’s. I heard manuals like bias ply but wanted to use the radials as a stepping stone. What do you recommend for economical datalogging set up?

Joe- will def check out Fartpipe’s thread/videos

name is Jerome btw

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Old 11-04-2018, 04:30 PM
  #23  
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The most effective way to get the most out of your manual launch is with a clutch slip device. There's just no way even a trained human leg can instantly release the clutch pedal to a precise point consistently. Here's a graph of hyd t-bearing psi during a release controlled by a ClutchTamer slip device, notice the sharp transition at the hit point from instant release to delayed pedal travel...



It basically allows you to near instantly release the pedal to a specific point within it's "sweet spot" zone, then a delay becomes active to keep the pedal in that sweet spot much longer to prevent a bog. The result is a consistent hit that's actually softer than an automatic, but lasts longer. Radial friendly too.

Grant
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Old 11-05-2018, 12:53 AM
  #24  
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Originally Posted by Huncle J View Post
Awesome, thanks!

James- those videos were the first time out on the MT’s. I heard manuals like bias ply but wanted to use the radials as a stepping stone. What do you recommend for economical datalogging set up?

Joe- will def check out Fartpipe’s thread/videos

name is Jerome btw
I have radials as well. If you come off the clutch right, you can do very well. best 60ft is 1.333 and hit 1.3x multiple times with a radial. As for the Data logger. I would look for a used version of HPT pro. a newer interface came out recently so i'd imagine some deals are out there on the old one.

Originally Posted by sr530 View Post
The most effective way to get the most out of your manual launch is with a clutch slip device. There's just no way even a trained human leg can instantly release the clutch pedal to a precise point consistently. Here's a graph of hyd t-bearing psi during a release controlled by a ClutchTamer slip device, notice the sharp transition at the hit point from instant release to delayed pedal travel...




It basically allows you to near instantly release the pedal to a specific point within it's "sweet spot" zone, then a delay becomes active to keep the pedal in that sweet spot much longer to prevent a bog. The result is a consistent hit that's actually softer than an automatic, but lasts longer. Radial friendly too.

Grant
Take it anyway you'd like but that sounds like someone just doesn't like practice. I have seen that device work for others very well, but I will argue that you can do it manually and be consistent. With a well prepped track I can bang out near my best 60ft all day long and I'm not even close to being the best.
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Old 11-05-2018, 10:33 AM
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Originally Posted by rpmextra View Post
I have radials as well. If you come off the clutch right, you can do very well. best 60ft is 1.333 and hit 1.3x multiple times with a radial. As for the Data logger. I would look for a used version of HPT pro. a newer interface came out recently so i'd imagine some deals are out there on the old one.

Take it anyway you'd like but that sounds like someone just doesn't like practice. I have seen that device work for others very well, but I will argue that you can do it manually and be consistent. With a well prepped track I can bang out near my best 60ft all day long and I'm not even close to being the best.
You may be able to do it manually and be consistent, but you are leaving quite a bit on the table with a manual 5k launch. I use the simple formula of 1320/mph=ET as an easy to remember way to generally compare overall power to 1/4mi efficiency. A well dialed manual trans car can generally come within a couple tenths of that formula on the track.

Grant
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Old 11-05-2018, 11:41 AM
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Originally Posted by sr530 View Post
You may be able to do it manually and be consistent, but you are leaving quite a bit on the table with a manual 5k launch. I use the simple formula of 1320/mph=ET as an easy to remember way to generally compare overall power to 1/4mi efficiency. A well dialed manual trans car can generally come within a couple tenths of that formula on the track.

Grant
Not to overlook anything and get away from actually helping the OP out rather than confusing him. Thats an old school auto formula that doesn't apply all that well to cars of today. Even less with imports, and somewhat less on manual corvettes. How many cars are running 10.0 at 132mph? With low drag coefficients, high rear gears, high 1st gear, the closest rule you can use with corvettes is the moroso rule which uses power/weight. That being said, even that would require the car to be very well dialed in. Does your formula translate well to say a buggati veyron doing [email protected]?

Going back to the device you speak of, it's a great tool. However, it would not allow you to read the track and make adjustments to how the track prep and car are performing. If the tires hook, and I know it, I'm out the clutch asap and want to get full power as soon as possible. I have not fiddled with these devises but I'm assuming they would A: require a lot of set up, trial and error adjustment. B: Require a clutch that can take a slip. C: require more attention to clutch heat.... A hot clutch will bite harder, much harder, than a cold one and that will play with your setting. D: would likely need to adjust for different track conditions as things will change, and so will your settings.

To me, it seems like something I would Maybe think about later on when someone is maybe trying a max effort setup. I'm sure it works great for those who know how to set it up and everything. I know a big name that used it in the passed with a lot of success with his max effort C5 but it's not something I'd suggest for people just getting started out. Its just my opinion of course and it ain't worth much to you I'm sure. I just don't think the OP needs such a tool yet at that level.
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Old 11-05-2018, 01:39 PM
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I appreciate all the help but you guys are a little over my head at this point. This is still my daily and I like the challenge of launching and rowing my own. I know I wont break any records, just trying to do the best I can with what I got and then get a little better (baby steps).
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Old 11-05-2018, 01:46 PM
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Originally Posted by Huncle J View Post
I appreciate all the help but you guys are a little over my head at this point. This is still my daily and I like the challenge of launching and rowing my own. I know I wont break any records, just trying to do the best I can with what I got and then get a little better (baby steps).
That's was exactly my point and I'm glad you confirmed it.

Do you have outside video? Would love see what the cars doing
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Old 11-05-2018, 01:52 PM
  #29  
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Originally Posted by Huncle J View Post
I appreciate all the help but you guys are a little over my head at this point. This is still my daily and I like the challenge of launching and rowing my own. I know I wont break any records, just trying to do the best I can with what I got and then get a little better (baby steps).
Truth is, practice it what it takes. And, it's a joy when you can launch your car and shift out a clean pass. Don't get that joy from an automatic so much.

I'd just raise launch RPM next time you go out there.

And...as I always say, if you get ANY wheel hop let out immediately. That is a sure fire way to break something.
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Old 11-05-2018, 04:06 PM
  #30  
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Originally Posted by Joe_G View Post
Truth is, practice it what it takes. And, it's a joy when you can launch your car and shift out a clean pass. Don't get that joy from an automatic so much.

I'd just raise launch RPM next time you go out there.

And...as I always say, if you get ANY wheel hop let out immediately. That is a sure fire way to break something.

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Old 11-05-2018, 05:47 PM
  #31  
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Jerome, I might suggest you level the car out, with our Vettes I don't think you need or want to lift the rear and lower the front for best ET's, I've never seen anyone do that and I wonder if it has something to do with your wobbly feeling, again, with your mods and drag radials I wouldn't expect you'd get wobble. If you've got the rear raised too much it dawns on me that you're messing with caster which might cause the wobbly feeling.
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Old 11-05-2018, 07:58 PM
  #32  
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Originally Posted by rpmextra View Post
Not to overlook anything and get away from actually helping the OP out rather than confusing him. Thats an old school auto formula that doesn't apply all that well to cars of today. Even less with imports, and somewhat less on manual corvettes. How many cars are running 10.0 at 132mph? With low drag coefficients, high rear gears, high 1st gear, the closest rule you can use with corvettes is the moroso rule which uses power/weight. That being said, even that would require the car to be very well dialed in. Does your formula translate well to say a buggati veyron doing [email protected]?

Going back to the device you speak of, it's a great tool. However, it would not allow you to read the track and make adjustments to how the track prep and car are performing. If the tires hook, and I know it, I'm out the clutch asap and want to get full power as soon as possible. I have not fiddled with these devises but I'm assuming they would A: require a lot of set up, trial and error adjustment. B: Require a clutch that can take a slip. C: require more attention to clutch heat.... A hot clutch will bite harder, much harder, than a cold one and that will play with your setting. D: would likely need to adjust for different track conditions as things will change, and so will your settings.

To me, it seems like something I would Maybe think about later on when someone is maybe trying a max effort setup. I'm sure it works great for those who know how to set it up and everything. I know a big name that used it in the passed with a lot of success with his max effort C5 but it's not something I'd suggest for people just getting started out. Its just my opinion of course and it ain't worth much to you I'm sure. I just don't think the OP needs such a tool yet at that level.
The formula is just a simple tool to generally compare overall 1/4mi efficiency. Nothing old school about it, useful for comparing auto, manual, even electric. It shows that Buggatti's [email protected] isn't very efficient in the 1/4, as compared to say these two dead hooking 3100lb cars running $7500 factory sealed NA 302ci crate engines on the spec tune, both running conventional 10.5" diaphragm clutches controlled by a ClutchTamer…




The Wallace calculator says it takes 571fwhp to go 10.237 at 3100lbs, Ford says the sealed Coyote crates make [email protected] That's what proper clutch control can do for you.

A ClutchTamer is probably the most cost effective manual trans tool you can add to improve your performance at the dragstrip, especially for beginners. There's just no possible way to screw up the adjustment enough to cause your clutch to be more aggressive than it already is. And properly adjusted, a ClutchTamer launch will be softer than an automatic, but that softer launch will last longer. It basically takes a clutch dump launch that's short duration but too aggressive, and consistently transforms that into a softer launch with more duration. In the end, you get a consistent dead hook launch without a bog that's quicker and far less likely to break parts. If you clutch is already too aggressive for a hi-rpm clutch dump start, you don't need more clutch to start enjoying those benefits.

Grant


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Old 11-06-2018, 10:29 AM
  #33  
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Originally Posted by Joe_G View Post
Jerome, I might suggest you level the car out, with our Vettes I don't think you need or want to lift the rear and lower the front for best ET's, I've never seen anyone do that and I wonder if it has something to do with your wobbly feeling, again, with your mods and drag radials I wouldn't expect you'd get wobble. If you've got the rear raised too much it dawns on me that you're messing with caster which might cause the wobbly feeling.
Joe, front is all the way up and the back is all the way down on stock bolts. The front is still slightly lower than the rear (I read that the rake is designed to help with high speed stability). Although lifting the front takes weight off the front wheels and allows more air under the car... I need to get more runs in before I start changing more things with any sort of certainty. Unfortunately not a lot of test and tunes left for the season (track closes Dec-Feb)
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Old 11-06-2018, 10:50 AM
  #34  
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Originally Posted by sr530 View Post
The formula is just a simple tool to generally compare overall 1/4mi efficiency. Nothing old school about it, useful for comparing auto, manual, even electric. It shows that Buggatti's [email protected] isn't very efficient in the 1/4, as compared to say these two dead hooking 3100lb cars running $7500 factory sealed NA 302ci crate engines on the spec tune, both running conventional 10.5" diaphragm clutches controlled by a ClutchTamer…




The Wallace calculator says it takes 571fwhp to go 10.237 at 3100lbs, Ford says the sealed Coyote crates make [email protected] That's what proper clutch control can do for you.

A ClutchTamer is probably the most cost effective manual trans tool you can add to improve your performance at the dragstrip, especially for beginners. There's just no possible way to screw up the adjustment enough to cause your clutch to be more aggressive than it already is. And properly adjusted, a ClutchTamer launch will be softer than an automatic, but that softer launch will last longer. It basically takes a clutch dump launch that's short duration but too aggressive, and consistently transforms that into a softer launch with more duration. In the end, you get a consistent dead hook launch without a bog that's quicker and far less likely to break parts. If you clutch is already too aggressive for a hi-rpm clutch dump start, you don't need more clutch to start enjoying those benefits.

Grant
So using the 1320/mph formula I should be running 11.37 (using 116 trap as low) to 11.18 (using 118 trap)? And the clutch tamer will do this for me?

that would put me near the top of the bolt on ls2 list and all I have is vararam, headers/exhaust and drag radials. No fast intake, no skinnies, 3.42 gears and a stock 138k mile clutch.

There are too many variables for that formula to work well. In my limited experience I have seen front half cars and back half cars run similar et but the back half car traps several mph faster...
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Old 11-06-2018, 02:22 PM
  #35  
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Originally Posted by Huncle J View Post


So using the 1320/mph formula I should be running 11.37 (using 116 trap as low) to 11.18 (using 118 trap)? And the clutch tamer will do this for me?

that would put me near the top of the bolt on ls2 list and all I have is vararam, headers/exhaust and drag radials. No fast intake, no skinnies, 3.42 gears and a stock 138k mile clutch.

There are too many variables for that formula to work well. In my limited experience I have seen front half cars and back half cars run similar et but the back half car traps several mph faster...
The formula gives you a general target as to your potential et given the trap speed. The car needs to be optimized to realize that potential. The clutch is but one piece of the puzzle, but it's the biggest piece as it's responsible for maintaining that balance between keeping the engine up where it's happy vs overwhelming the tires.

Notice that every single automatic in the top 10 on that list says "conv". That's the automatic equivalent of adding some clutch slip to keep the engine up where it's happy. I didn't see a manual car anywhere on that list that listed a single thing about their clutch.

You have the power to run 118 in the 1/4. Fast intake will affect the power/mph, so it doesn't really make a difference as to power vs et efficiency. No skinnies and 3.42 gears do make a difference, those things should be optimized to reach your efficiency target. Your stock clutch likely will not be up to the task, but you can improve your current results up to the point that your stock clutch reaches it's limits.

Grant


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Old 11-06-2018, 11:12 PM
  #36  
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Originally Posted by Joe_G View Post
Jerome, I might suggest you level the car out, with our Vettes I don't think you need or want to lift the rear and lower the front for best ET's, I've never seen anyone do that and I wonder if it has something to do with your wobbly feeling, again, with your mods and drag radials I wouldn't expect you'd get wobble. If you've got the rear raised too much it dawns on me that you're messing with caster which might cause the wobbly feeling.
I Agree with Joe here. I have my car set on factory bolts on factory height. Never touched. The cars squats just right and 60s great and consistent mid 1.3x and have a best 1.333 60ft. I would try to listen to Joe (it served me well) as he knows how to get the most out of that factory clutch which he has nearly 500 passes on his.

Also, there are 2 things you can play with that need to be just right.
1: launch RPM
2: Tire Pressure

You can increase your launch rpm in 200-300 increments, if its biting well but you do not want to raise the rpm further for whatever reason, you can then start bumping up your tire pressure say 0.5-1.0psi before your burnout.
You need to figure out what your driving style, and car wants to come off the line. Once you have that figured out, you can likely dial in your launch after one pass at the track. You'll see and feel where the track prep is at and knowing what works, can adjust very quickly.

It's basics you want to go to. that yields the biggest results and most of the time they are free. Once you hit a plateau, then you can move on to the next thing. I went from 11.7 to 10.33 in one season changing absolutely nothing on the car in 2015. It was a fantastic yr and had new bests almost every weekend out. Joe knows, he was a big part of it. took me until this season to repeat that fun factor as again this yr was full of new bests in every way.

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Old 11-18-2018, 07:57 PM
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I will be getting one of these. I went to the track for for the first time a few months ago and I was bogging so bad it was horrible. I currently put 720 to the ground and could only run 8.0 in the 1/8th. I ran that with a 93 mustang with C/H/I! I am running a set of 28" M&H Racemasters that are brand new. I will be going to E85 and going to a LOT smaller pulley come tax time.
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Old 11-19-2018, 11:33 AM
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If you are not getting the power you have down now, why add more power?

waiting for the track to have another TNT so I can get some more practice/data
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Old 11-19-2018, 11:48 AM
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I am hooking 100%. Just hooking and doing a dead bog. I was also having to hold the break because my car was rolling back once staged. The mechanical device will allow me to "dump" the clutch and forget about it once set up correctly, hopefully.
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Old 11-19-2018, 11:20 PM
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Originally Posted by Daddy Freeman View Post
I am hooking 100%. Just hooking and doing a dead bog. I was also having to hold the break because my car was rolling back once staged. The mechanical device will allow me to "dump" the clutch and forget about it once set up correctly, hopefully.
I don't wanna pick on ya but you go 1 time to the track and immediately look for alternatives? If you are dead hooking and bogging you need to raise the launch rpm up, or try more air in the tires and experiment a little with your clutch release speed. If you bog off the line it will hurt your times that's correct I won't argue there. That being said, you are about 2 seconds off where you should be at the 8th with that kinda power and I doubt (without seeing a timeslip) that it's all with your 60ft. Sounds like you need some seat time and a little patience. It's not a bad thing to learn. It's actually the fun part of drag racing itself. Constant improvement and frequent new personal bests puts a lot of smiles on our faces my friend. Enjoy it, that's my advice.

I don't believe those devices would help much for those who can launch properly without one. Maybe I'm hard headed but main reason I stayed manual was to say I'm the one in control. I like knowing I can always improve upon my times because I know I can launch harder or shift faster etc.

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