TimZ

It might have something to do with the fact that this forum was established specifically to support people interested in doing SBC swaps on their Z's. That's what the "hybrid" in HybridZ refers to. The originators of the site were gracious enough to let the rest of us in.

That's what it looks like, yes.

Evan - I don't remember what injection system you are running - can you datalog an example of this happening? Like Gabe, I'm curious about what rpm this starts at and when (or if) it stops once you pass through a certain rpm.

Sorry, but not quite. An inertia dyno only looks at the acceleration of the drum to calculate the horsepower at the tire/drum interface. Technically this is measuring the torque at the wheels, but the more interesting number is the resulting horsepower. The hp number calculated here is independent of what gear the trans is in. In lower gears the time it takes to run the engine through an rpm range is less, but so is the change in speed at the drum (not coincidentally by the same amount). Engine torque is then calculated using the measured engine rpm and the formula torque(lb-ft) = 5252 * horsepower/rpm So, the horsepower and torque numbers generated by the dyno should be independent of what gear was used. Mostly. That said, there are differences that will show up that are dependent on the gear. For instance, The drivetrain loss increases in lower gears. Conversely, if you are turbocharged/supercharged, the longer pulls in higher gears allows the intake air temps to climb higher during the pull due to heat soak in the intercooler. The quicker pulls in lower gears will have fewer samples to calculate acceleration from and will tend to give noisier results (acceleration calculations are noisy by nature, so it helps not to make it worse if you don't have to).

I seldom miss a Zappa reference.

That's right - the starter bolt is where this generally is connected. The starter is by far the largest current draw in the vehicle, so you want the most direct battery connection to go to it. The location on the trans is okay, but I wouldn't go any farther than that from the starter. I run my ground strap from the same spot on the starter to a good body ground - that way the engine and body are more likely to have the same ground reference level. I don't like having the chassis ground and engine ground voltage moving around with respect to each other.

+1 Not a big giant wing fan.

I might be totally wrong but I'm a... DANCIN' FOOOO-OO-OO-OO-OOL

Easiest way to tell on the firmware is what version of Wintec runs with it - should be 3.x.x - what are the x's? What wideband are you using, and do you have it interfaced with the TEC's analog input (EGO input or A/D4) so you can log it synced with everything else?

The tuner has the timing and fuel curves. If he doesn't you need to find a new tuner. Just curious - what firmware are you running in the Tec3r? Also, do you have a wideband?

Agreed, but it's WAY more space efficient than an X-pipe and two mufflers.

You might consider a pair of Mickey Thompson E/T Street radials in 275/40-17. Made a night and day difference for me over my previous Kumho Victoracers.

Problem is with the number of gear reductions taking place, the losses are asymptotically approaching 100%. Also, the gears need to be able to handle the amount of torque that they are transmitting - that trans is bound to shatter the gears long before it does anything terribly interesting.

This was for a turbo setup - there is a 4" oval for the turbine outlet (downpipe), and a separate 2.25" inlet for the 60mm wastegate. They cross over internally very similarly to the dynomax piece shown above, and exit through two 3" oval pipes. The exhaust is roughly even with the bottom of the frame rails. Towards the front where the wg outlet crosses under the trans it hangs down a bit more (maybe 1/2"), but this would probably not be an issue with a V8.

Actually that should fit just fine in the trans tunnel under the driveshaft - you could run a pipe out each side in front of either tire. Here is what I did with a similar custom-made piece for my turbo setup...

I was thinking the same thing - I guess technically this would be compressor surge, but it's happening at such low pressures and turbine speeds that I doubt it would be of any concern. If you start seeing this behavior when under boost that would be a different matter, but I would imagine that you would notice that.

That would be my guess - it's a naturally aspirated engine and I think they use it to increase backpressure at low rpm for better response. Maybe they don't like the opening points or something?

The throttle plate, shaft and bushings are all made from HastelloyX, an Inconel-like alloy with higher temperature ratings, so hopefully it should hold up. We went through the thermal expansion numbers to (hopefully) make sure that nothing would seize up. Also, since I'm running E85 there isn't much in the way of exhaust residue to crap things up. The position controller that I'm using allows me to command the throttle position in ~200 steps, commanded by the TEC3r's GPO table, so I'm only limited by the speed that the motor can open and close the valve. What you described is pretty much exactly how I'm controlling it. I haven't heard from James in a while - I think he's been pretty busy with life in general lately.

Yeppo.

Wheelspin. The reference was from a 4th gear pull on a dyno with no wheelspin, the "current" was from a 3rd gear pull on a less than perfect stretch of road (my usual stretch of road is under construction). That's why mentioned to ignore the hp and torque numbers. I should have been clearer on that - for now I was just trying to show the boost/RPM relationship for before and after. Joe - it doesn't matter which half I block off, so long as I block one of them off. My 1.15AR split turbine housing is essentially a pair of .575AR scrolls that act on the same turbine wheel. If I block one of the scrolls off, it turns the turbine housing into a .575AR housing for better spool (think of putting your thumb over the end of a hose). Then as I start making power, I can open the SpoolieJobbie back up and get the full 1.15 AR. Make sense?

Yes, that right - SpoolieJobbie lives again! (In case you don't remember SpoolieJobbie, it was first talked about here ) When I first tried to implement this I had some serious problems finding a reliable actuation method, and the turbo that I had before was just to small to benefit from cutting its A/R in half. Since this isn't really a problem with the 1.15AR GT42R that I'm using now, I started thinking about dusting this project off. I started poking around on eBay and found that the GSX-R bike comes stock with a similar device, and it's owners often strip this off, thinking it buys them horsepower. So, I picked one of these up for cheap - as it turns out it's even setup with position feedback for use with a position controller. The setup drives a pair of push-pull cabls that control the throttle position, so the motor can be mounted remotely. I decided to actuate the throttle through a stainless flexible shaft, so the cable assembly is also isolated from the heat. A little more poking around turned up this position controller, that is capable of taking an analog input from my TEC3r and controlling the throttle position to it. And I'm off and running... Initial results are looking pretty good - the graph at the bottom clearly shows the new boost response (ignore the horsepower curve - I had to back off a bit at ~5100rpm due to wheelspin).

+1 on the heat shield and gaining some space. On the Coating - use the 2000 deg variant, and don't get black. Have you looked at putting some expansion joints in there anywhere? I think you'll be happier in the end if you do.

Probably more like 1.5 - 1.7. Max power rich for turbo engines on e85 is down around 7:1 AFR. You can probably go leaner on an NA setup. Also, at max power rich you should expect ~10% more power. E85 isn't great on bare aluminum, although there seem to be pently of people out there doing just fine with it. Simple fix is to find an anodizing shop and have the aluminum bits anodized (it's not that expensive). Old rubber hoses should be replaced with compatible ones (not expensive and not hard to find - NAPA's fuel hose is compatible). Here's the one that might be a probem with SU's - NO BRASS. I would have guessed that there were brass bits on the inside of an SU. Can you get non-brass replacement parts? Do a search on E85 - I know I've gone over this in more detail before. I will say this - once you are up and running on E85, you won't want to go back to gasoline!

Thanks Chris - that is a really good paper. Mods - could we move this to another forum where more people will see it and make it a sticky? Maybe this could cut down on the "you don't need a 'balancer' if your crank is internally balanced" discussions.

I was using the Stewart Components thermostat http://www.stewartcomponents.net/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=Therm ...which looks very similar- its basically a Robertshaw high flow unit with some bypass holes drilled in it. With this thermostat I had some serious problems getting the car to operating temp, especially on cool nights when the temps often wouldn't go above ~165 degF (195 degree stat). On warmer days the temperature would often swing from 170 to 200 degF for no apparent reason. Surprisingly, I tried putting a stock thermostatstat back in, and it worked just fine. I had installed the high flow unit when I was trying to use the electric water pump - apparently it wasn't helping but I couldn't tell. It could be that the bypass holes were contributing to the problem, but I suspect that the opening gain for the high flow stat didn't match the characteristics of the engine.