Car should dyno this week, anyone want to guess what it does..

[jessrayo]

So for you guys that may be wondering, I didn't set any records at the strip on Friday. I only made 3 passes and I broke something in the drivetrain/transmission on the 3rd pass. Right now I've got the car stuck in 1st gear and it won't shift at all.

Nobody wanted to be the first car to run so not a car was in the lanes when the track went hot. After waiting 10 minutes, I made the first run of the night and spun the tires through the first 2 gears, 11.1. I came back and launched at 3000 to try to keep from blowing the tires off, bogged the motor out the hole and ran 11.0 at 141. Third pass had a pretty good 4500 rpm launch and 1.60 60ft but something broke on the 3rd to 4th shift, coasted a 10.8 at 134.

I coasted onto the return road and tried to get it into a gear, shut it off and looked underneath with no signs of damage, wrestled with the shifter some more with the car off and it wouldn't engage the gears, when I started the car, it still would not shift but when I let the clutch out it was in first gear... I didn't have a trailer at the event so I drove home 7 miles in first gear. So at least now I can start it and roll it in first. I'll try it again next year.

[vatechguy3]

Sorry to hear that!

Lets us know what you find when you tear into it.

Tony

[10aSSee D]

What tranny are you using?

[jessrayo]

Originally Posted by 10aSSee D

What tranny are you using?

It is the stock transmission that basically has the level 7+ upgrades and custom ratios from RPM transmission. I don't really know for sure if the linkage is the problem or something in the transmission itself.... to be determined. I've been putting more stress on it because the clutch doesn't work as well when it is hot and even though I let it rest at least 30 minutes between each pass, I could tell the clutch was still hot on the last run. Still have some gremlins to work out of everything.

[Trackman]

Another first!
....first to tweak a ZL1 rear diff.
....first to munch a stick tranny.

[mylftft]

I've got a couple 6L90's if you want to swap to an auto!

[1KillerSS]

Originally Posted by jessrayo

coasted a 10.8 at 134.

Sorry you broke something, but damn man, that's really a sweet ride....one day your going 200
MPH at texas, then the next weekend your at the drag strip running 10.8 with a broken car.

[white ZL1]

On the pass the car broke, what was the 1/8 mile time? Might give you a decent idea of what that pass "could" have been?

[revobasher]

Sucks about the trans issues.. need more pics and a vid!

[GenF-GTS]

waiting on pics and video

[AZ-ZL1]

Damn Jess. You may not have the fastest ZL1 (yet) but it may be the most expensive.

Hope it's something minor.

[jessrayo]

Originally Posted by AZ-ZL1

Damn Jess. You may not have the fastest ZL1 (yet) but it may be the most expensive.

Hope it's something minor.

It makes a lot of power but I have not been able to bring everything together at the last few racing events. I keep upgrading to try to make it indestructible but haven't got there yet. I haven't heard anything on the transmission or the clutch rebuild yet. I'm not in a big hurry but spring will be here in short order and I'll want to run it again.

[Chrispy]

It's a very cool and unique concept but why wouldn't you run larger turbos and skip the heartbeat? With 434 cubes it'd spool super quickly even with twin T76s and make similar power

Really enjoying reading about your build.

[jessrayo]

Originally Posted by Chrispy

It's a very cool and unique concept but why wouldn't you run larger turbos and skip the heartbeat? With 434 cubes it'd spool super quickly even with twin T76s and make similar power

Really enjoying reading about your build.

I definitely do not need bigger turbos..... The dyno sheet on post 131 is with just turbos. At 140 mph or roughly 5500 rpm on that run the tires spin on the dyno. The peak dyno graph is the most power we could register before the tires lost hold. These turbos can easily run 30 pounds of boost. We are opening wastegates at 22 on this run.

Frankly the acceleration is almost uncontrollable with the lag and nature of the way these turbos hit. The blower brings the bottom end of the graph way up and makes the engine respond instantly to whatever throttle input you give it.

If you look back at my dyno sheet on post 131 I will talk you through the sheet and describe what happens when you drive this,
1. Pull starts at 60 mph or about 2350 rpm. Making 175 hp when throttle body goes wide open. From here until point 2. is turbo lag.
2. Around 75 mph or roughly 3000 rpm there is still no boost and the car only gained about 25 horsepower over the last 700 rpm so it is now at 200 hp when we begin to ramp in a 75 shot of nitrous to get the turbos going. (without nitrous lag is severe until 3500 rpm and acceleration is at same rate until 4500 rpm where it peaks)
3. Around 105 mph or 4150 rpm. The 75 shot of nitrous is fully ramped in and the turbos are close to full boost. So over the last 1100 rpm the car gained 1000 horsepower. Think of it this way, once the car goes over 3000 rpm, every single rpm adds another horsepower. Not quite that good but very close, if you are not going ridiculously fast to harness that power it begins to spin and the second the tires start to spin it is like feedback in a PA system that feeds on itself until the engine hits the limiter very hard. If you feel it spin and pull your foot off the throttle as fast as you can you hear the blowoff pop at the limiter almost exactly the same time your foot comes up.
4. On the dyno we started to ramp in another 100 shot of nitrous at 5000 rpm or about 130mph, we ramped this one slow but when the car hits 140 mph or 5500 rpm the tires spin on the dyno and the horsepower graph drops because tires spinning do not produce horsepower. Tires spin to the limiter as described above and pull is stopped on limiter.

The car is pretty hard to control with this set-up. From 3 to 4 thousand rpm the car hits like a bomb if you can get traction, if not the tires stop spinning on the limiter.
In this mode rule 1: do not accelerate unless car is pointed straight.
Rule 2: If car is pointed straight and you are going less than 150 mph on a non-prepped surface and you try to accelerate beyond 4000 rpm, the car will get sideways, see rule one.

It is kind of fun just to throw up crazy tire smoke at 100 to 150 mph but to put it bluntly, in this configuration the power is almost unmanageable. So I want to get the supercharger back on and get that instant feedback.