Yellow Bullet Forums banner

1 - 20 of 20 Posts

·
Registered
Joined
·
761 Posts
Discussion Starter #3
Took the 'Vette out for some little shakedown passes with the new clutch. Works well! Of course it was just some launches on pumped up cold drag radials on the highway...but felt good. It shifts clean and no slippage as RPM climbs. I've got a lot of centrifugal assist on it...so it's holding well. Ran it up through 7000 RPM shifts and 130 MPH or so a few times...

Did have some popping under boost. Came back home and backed off the timing and actually leaned it a little and it did a lot better on next hits. Guess 93 octane that's been in the tank a few months isn't what it was when first put in huh? Still had a little roughness up there...but revved a lot cleaner. Plugs still look rich but safer fat than lean and hard to tell if gas is funky. Kept boost to about 17-18 psi..so not radical.

Sure is fun to play!! Time to get it to the track on some slicks and make some passes!


JIM
 

·
Registered
Joined
·
761 Posts
Discussion Starter #5
[email protected] MPH!

Finally got a chance to hit the track. The weather was great and track prep was fantastic.

The new clutch setup from Cale uses an aluminum flywheel, is 11" vs 10.5" and has a different combination of springs, levers and centrifugal weight. It was designed to allow me to come out of the hole a lot harder with the proper slippage than I could previously and still be able to lock up and hold the power down track.

I had no idea where to begin with the "tune" of base pressure to go along with the large amount of counterweight I had installed. Cale suggest "7 turns" on the adjusters to start out high and then back down as needed. I initially set it up that way...but decided to drop it a full turn to remove some pressure considering I didn't know how track prep would be. I also started with the power turned down by pulling a lot of timing.

They had some "roll racing" there too...which I had never tried. But I figured it's a good way to ck on the engine tune and see how it's going to act. I wasn't sure the clutch was going to like it...but it worked perfectly there too. On the first attempt we "hit it" at about 40 MPH or so. I had it in second gear at around 4000 RPM...it took it OK and pulled through at about 146 MPH at the end of the 1/4. On the next try I added a little fuel to it...as it looked a little lean on the plugs. It responded well and picked up about 6 MPH at the 1/8th mile point....but my hand slipped off the shifter when I pulled 4th gear and only showed 141 mph. BUMMER! (note to self- wash oil and grease off hands better after messing with plugs!). Next try I kept it in first gear at the 40 MPH or so hit at about 5000 RPM...it really liked that! Hit 150 MPH this time!

Later I got first chance to try a launch and do a 1/4 mile pass. I came out at about 4000 RPM and made all shifts at 7500 or so RPM. Ran a [email protected] MPH. Not strong on big end...but I still had it dialed down.

I was only going to get one or two more runs in so I added some timing (which it always loves!)

Long story short...launched at about 5000 RPM....and made shifts close to 8000 again and it ended up with the 8.89!! Still not as strong on the front half as I like it...but it was a freight train at the end once everything came together!

Been a long time coming!

JIM
 

·
Registered
Joined
·
63,754 Posts
Awesome!!
 

·
Mike
Joined
·
7,100 Posts
You've worked hard to get it Jim, great accomplishment, I'm very glad to hear it.:smt023:smt023

Clutch assisted GF5R 3.08 rear.
 

·
Registered
Joined
·
761 Posts
Discussion Starter #17
Thanks....I was just happy to get down the track in a somewhat smooth manner. The last couple of tries haven't been pretty. Had to use way too much pressure to hold the HP and had to bog it out of the hole. This time I at least was able to launch with a little RPM AND hold the power and make some MPH. It's run 161+ MPH in the past...so there's still some left.

I'm sure there's a good bit of ET left in it....but again....lots of compromises in this car. 3.07 rear gears and trying to make up the rest in the trans. It's not light etc. I'm still launching with zero boost and no boost controls...just manual wastegates.

My goal has been to crack it into the 8's after I hit the 200 MPH mark at the TX Mile and still cruise to the Sonic to get a drink or drive cross country with nothing but a tire change. Finally got there...had to build a little more power than usually needed to deal with a far less than optimum science out street cruiser...but it worked.


JIM
 
1 - 20 of 20 Posts
Top