Test-N-Tune Night
Thread Starter
Race Director
Joined: Jan 2000
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From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Test-N-Tune Night
After going to Houston to pick up my new hardtop....I swung by a track I'd never been to before for a test-n-tune night at Pine Valley Raceway in Lufkin TX. I had some friends tell me how neat it was so I decided to see for myself.
First run with the new Hoosiers was awful slippery and all over the place. Thought I had burned them in pretty well...but they didn't like the higher RPM launch. Ran a 9.95@148MPH.
I came back around with only a little cool down and the engine temp showing 200*. I came out a little softer and it did a whole lot better and straighter with a 9.10@158 MPH. Even had a .007 light! So not an 8 sec pass yet...but a new best and not too bad for a warm/muggy evening in TX.
Sadly, that was the best pass of the evening. There were a couple of oil downs that slowed things but I still got in a couple of 9.30's.
I had backed off the clutch pressure some but this proves I can take out some more. It will sometimes get air under the front tires on the 1-2 shift...but last night it was seriously doing it...much more than ever before with the new slicks....which got a lot of comments from the spectators but not the quickest way down the track. Makes for great pics off the line and down track...but I think I may tighten it up the front suspension some before next weekend when I take another crack at it.
I think it's time to crank some boost into this thing!! Seems pretty consistent speed wise lately. Now getting the first part of the run right will make the difference.
They did tell me I was the "fastest MPH" car there last night even against a big block dragster!
Anyway...I REALLY liked the track. It's in the woods of SE TX, but the owners are super friendly and everyone was great. It has a nice long shut down area, smooth and they were prepping well even for play night.
JIM
First run with the new Hoosiers was awful slippery and all over the place. Thought I had burned them in pretty well...but they didn't like the higher RPM launch. Ran a 9.95@148MPH.
I came back around with only a little cool down and the engine temp showing 200*. I came out a little softer and it did a whole lot better and straighter with a 9.10@158 MPH. Even had a .007 light! So not an 8 sec pass yet...but a new best and not too bad for a warm/muggy evening in TX.
Sadly, that was the best pass of the evening. There were a couple of oil downs that slowed things but I still got in a couple of 9.30's.
I had backed off the clutch pressure some but this proves I can take out some more. It will sometimes get air under the front tires on the 1-2 shift...but last night it was seriously doing it...much more than ever before with the new slicks....which got a lot of comments from the spectators but not the quickest way down the track. Makes for great pics off the line and down track...but I think I may tighten it up the front suspension some before next weekend when I take another crack at it.
I think it's time to crank some boost into this thing!! Seems pretty consistent speed wise lately. Now getting the first part of the run right will make the difference.
They did tell me I was the "fastest MPH" car there last night even against a big block dragster!
Anyway...I REALLY liked the track. It's in the woods of SE TX, but the owners are super friendly and everyone was great. It has a nice long shut down area, smooth and they were prepping well even for play night.
JIM
Last edited by 427Hotrod; Sep 9, 2017 at 06:46 PM.
Thread Starter
Race Director
Joined: Jan 2000
Posts: 13,011
Likes: 2,250
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Yeah...going to need to do some different stuff. It's pretty much proven that whatever it is....where I'm at is where I'm at.
I'm whittling away at hundredths but I'll get there!
JIM
I'm whittling away at hundredths but I'll get there!
JIM
Thread Starter
Race Director
Joined: Jan 2000
Posts: 13,011
Likes: 2,250
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
I've got another shot this weekend!!
JIM
JIM
Safety Car
Joined: Apr 2006
Posts: 4,057
Likes: 421
From: BC
Evening JIM. I was wondering about your launch technique. What rpm are you leaving with and are you sliding the clutch slightly or just dumping it off the line? 8's look to be in your near future but running 9's and driving it home or out for a bite is kind of an awesome sort of cool. Keep it up!
Thread Starter
Race Director
Joined: Jan 2000
Posts: 13,011
Likes: 2,250
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
I've got an adjustable racing clutch- a Mcleod Soft Lok. You can adjust the static spring pressure as well as add weights to the levers to increase centrifugal assist. I'm in the process of figuring out the clutch "tune" for the turbo combo. I had it down pat when it was N/A.
When it was N/A I would dump the clutch at around 5500 RPM. It would slip enough to keep RPM up and not bog engine and also hit the tires hard enough to get moving.
The turbo combo is launching with no boost right now..unlike guys with automatics who build boost against the converter. Us stick guys can do it too by pulling tons of timing but I'm not that far along yet. The first time I went to the track it was way too loose and clutch slipped all the way down the track. Next time it was too tight and would blow the tires off and leave black marks the length of the track. This time I had backed off some but with new slicks it was a whole new game and it needed to be backed off more. I'll do that by this weekend. On these runs I was only launching at about 3500 RPM because it wanted to pull front end up high and then spin. When the boost hits... it hits hard. I want to get back to launching around 4000-5000 RPM and be up in the powerband quicker. That's going to take some more clutch slippage.
But for a car with a normal clutch and fairly decent traction...you want to come out hard enough to spin the tires about one full revolution on the hit. That will reduce breakage and keep RPM up. Dead hooking breaks stuff. This will usually take some controlled foot work with the clutch and throttle to keep it moving.
JIM
When it was N/A I would dump the clutch at around 5500 RPM. It would slip enough to keep RPM up and not bog engine and also hit the tires hard enough to get moving.
The turbo combo is launching with no boost right now..unlike guys with automatics who build boost against the converter. Us stick guys can do it too by pulling tons of timing but I'm not that far along yet. The first time I went to the track it was way too loose and clutch slipped all the way down the track. Next time it was too tight and would blow the tires off and leave black marks the length of the track. This time I had backed off some but with new slicks it was a whole new game and it needed to be backed off more. I'll do that by this weekend. On these runs I was only launching at about 3500 RPM because it wanted to pull front end up high and then spin. When the boost hits... it hits hard. I want to get back to launching around 4000-5000 RPM and be up in the powerband quicker. That's going to take some more clutch slippage.
But for a car with a normal clutch and fairly decent traction...you want to come out hard enough to spin the tires about one full revolution on the hit. That will reduce breakage and keep RPM up. Dead hooking breaks stuff. This will usually take some controlled foot work with the clutch and throttle to keep it moving.
JIM
