The Mule rides again (sort of) - pics.

[CincinnatiFiero]

Bought a 911 from a guy with a friend of mine, the previous owner drove us to the bank in it and he wound it to nearly 4k rpms and slipped the hell out of the clutch on the way out. No wonder why he had a recent receipt for a clutch that had to be replaced at oddly low mileage.

But yes, I've seen Fiero people do that.

[The Dark Side of Will]

Twisted the splines off the left inner CV joint cup. I drilled and tapped the stump and removed with a slide hammer. I had another cup on the shelf and was able to replace it yesterday... drove the car back to NoVA last night.

Pics to follow.

[alltrbo]

Suweeeeeet. Glad to hear that it wasn't the trans.

Please let me drive it this time before you break it again.

[Sinister Fiero]

I don't see why one shouldn't be in high gears at low speed, as long as the clutch isn't slipping.

Never said you couldn't, I said it in the context that it is a bad idea to be in those higher gears and then try accelerating in them on a new clutch (that hasn't been broken in yet). ESPECIALLY IF you are one of those people who doesn't have the awareness of being able to tell whether or not your clutch is slipping. I bet there is a very low percentage of people who can actually feel if their clutch is slipping or not, and even a lower percentage still that actually pays attention to that all of the time they are driving their car. I think the bulk of people behind the wheel have "tunnel vision" and are very unaware of what is going on around them (and even what is going on with the car) while they are driving.

People actually do that???

Yes, I can't tell you how many people I see do that. I had one other Fiero customer in particular I can remember quite well who left here who did it on a freshly completed swap. He turned the corner at the 4-way stop and I counted 4 shifts before he was out of sight of me - I can honestly say he couldn't have been going faster than 40mph by the time he was in 5th gear. Worse yet, I heard him applying considerable throttle while in 5th to accelerate up past 40.

What can I say? Old habits are hard to break. And no amount of verbal instruction seems to get thru to some of these people. Now I don't want to verbally beat-up any of my customers; but what am I supposed to tell them when they call me 2 weeks or so later complaining about clutch chatter right after I witnessed the way they drove as they left here?

That's why I get a kick out of these "people" on the forums who always march around proclaiming that a "true sports car" has to have a manual trans - when most of those same people can't even drive one properly! (Now, obviously, there are people who know how to properly drive a manual trans equipped car so this statement doesn't apply to the entire Fiero community. But I do have to admit that most of the Fiero owners I've seen driving manual-trans Fieros are driving it in such a way that isn't "healthy" to the clutch, trans, or both).

[The Dark Side of Will]

I don't see why one shouldn't be in high gears at low speed, as long as the clutch isn't slipping.

He turned the corner at the 4-way stop and I counted 4 shifts before he was out of sight of me - I can honestly say he couldn't have been going faster than 40mph by the time he was in 5th gear. Worse yet, I heard him applying considerable throttle while in 5th to accelerate up past 40.

I wouldn't upshift that soon the *VERY FIRST* time I drove a swapped car, at least not until I figured out how the engine delivered its power, but beyond that I don't see anything wrong with it.
I can't understand how someone would *NOT* notice a clutch slipping.

For the record, the Northstar pulls 1100 RPM in 5th at 32mph just fine, so I do that when I'm in neighborhoods.

[The Dark Side of Will]

The track prep was very good. One of the first guys I talked to before I made my first run said that traction was good.

There were only a couple of other street cars there... Two Hondas running in the 10.2 range. I was the fastest real street car there, although a couple of the obviously dedicated drag cars that showed up on trailers had plates. I think the fastest time I saw on the board was 5.0xx, but I only watched a fraction of the passes that evening.

I was working on both my launch technique and my clean-off spin technique. I overdid the clean off spins and had some minor wheel hop. That may have contributed to the CV spline failure. I had the clean off spin perfected for the 4th pass..., just the right RPM and clutch slip to get 1-2 full revolutions of the tires with no wheel hop.

By the time I made my 4th run, both tires and pavement were nice and sticky. I was getting used to the clutch and felt that I had the RPM and slip figured out to cut at least a 1.8 short time if not a 1.7. Obviously, there were other circumstances of which I was not aware. If I'd done the 1.7, I definitely would have gotten a 7.9.

[Sinister Fiero]

I can't understand how someone would *NOT* notice a clutch slipping.

You and me both... But then again that makes me think of how many people I talk to that never see that deer standing just 3 ft off the side of the country road they just zoomed by doing 60mph that they never saw. Some people just don't pay attention to anything when they are driving.

You are ultimately correct. There's nothing wrong with shifting into the higher gears at low speed SO LONG AS the clutch is not slipping AND you don't apply enough power to get it to slip. However, try explaining the dynamics of all this to a customer (that doesn't know all that much about cars to begin with) and see how fast he or she gives you the deer in the headlights look (no pun intended).

[The Dark Side of Will]

You are ultimately correct. There's nothing wrong with shifting into the higher gears at low speed SO LONG AS the clutch is not slipping AND you don't apply enough power to get it to slip. However, try explaining the dynamics of all this to a customer (that doesn't know all that much about cars to begin with) and see how fast he or she gives you the deer in the headlights look (no pun intended).

I don't see why a new clutch wouldn't slip like a worn out clutch. The difference between the coefficients of static and dynamic friction means that once a fully applied clutch breaks loose, it lets go completely until the applied torque drops to less than what the coefficient of dynamic friction can handle. IE, it won't see just a few hundred RPM of slip... once it starts to slip, the engine RPM should climb very quickly... almost like a free rev.

[chuck]

How do your times compare to your old engine and what do you expect in the quarter?

[Sinister Fiero]

I don't see why a new clutch wouldn't slip like a worn out clutch. The difference between the coefficients of static and dynamic friction means that once a fully applied clutch breaks loose, it lets go completely until the applied torque drops to less than what the coefficient of dynamic friction can handle. IE, it won't see just a few hundred RPM of slip... once it starts to slip, the engine RPM should climb very quickly... almost like a free rev.

You would think that would be the case but I can think of a few instances where that wasn't exactly what happened. For example: I could tell a new clutch was slipping a very little bit, but there was no "run-away" of engine RPMs; and I, of course, reduced throttle as soon as I noticed the condition. It wasn't slipping much at all, but I could tell it was slipping. I'm sure if I would have increased throttle, it would have slipped worse. Of course, this was a brand new clutch with no miles on it and the more I drove the car, the better it grabbed as it "seated in" to the flywheel and pressure plate.

[The Dark Side of Will]

How do your times compare to your old engine and what do you expect in the quarter?

Hehe... you're going to make me dig up the scans of my old timeslips...

I think there's a standard NHRA table for 1/8 to 1/4 conversions... the websites I've looked at all say a 8.15 converts to 12.71, *BUT* there's obviously more to it than that. A car on slicks running an 8.15 with a 1.5 sixty is going to be slower in the 1/4 than a car running the same 1/8 time with, say a 1.946 sixty. I don't know which paradigm the table author assumed.

[The Dark Side of Will]

Also fixed the cooling system bleed fitting.
This fitting is directly responsible for the episode that led to the original Northstar cracking a liner and necessitating my ten year build.
It was originally connected to the pressurized overflow tank via the throttle body coolant line. Since neither of those components are present in the Fiero, I just capped it off and used it to help bleed the system. The problem is that durable caps are not made anywhere. The caps would fail and cause the engine to lose coolant. Now I have a purpose-built bleed fitting which will not do that. Using a lower pressure cap on the rear fill than the radiator fill, I have never had a problem with keeping the engine cool. However, it may take a heat cycle or two to correctly purge the system.



Edit: Looks like I need to do something about the heater inlet cap as well... I've been thinking for a while that using the stock Northstar heater pipes that wrap around the block along with the '85/'86 V6 heater return that connect to the rear of the waterpump would allow the Fiero and Northstar systems to connect very easily as well as clean up the engine bay... now I just need to *find* those components.

Interesting and detailed article on cooling systems: http://www.pirate4x4.com/tech/billavista/Cooling/
I've recieved similar Northstar-specific advice from Allen Cline regarding plumbing the bleed fitting on the water manifold to a pressurized surge tank. I had disregarded it because I wasn't having any overheating or temp control problems, BUT if I'm going to be tracking this car and pushing the cooling system hard, I may have to rethink that approach.

Russ on Pfiffle also installed the stock Cadillac (or was it a Corvette unit?) surge tank in his IMSA Northstar car.

[chuck]

Thanks, and no, I wasn't trying to make you dig up old slips or anything. I'm just trying to get a reference for where the car should be going down the track. I ran a 14.2 at 106 with major shifting issues and a best of 13.4 at 106. 3800sc cars seem to run faster times and lower mph so I was wondering where you were at for comparison.

[The Dark Side of Will]

I ran a 13.2 @ 102 my first time at the strip and then a 12.86 @ 106 my 2nd time. I do have scans of my old slips, just on a different hard drive... might be able to find those early next week.

[The Dark Side of Will]

The following was my best on the previous engine:

R/T: 1.064
60: 1.929
330: 5.406
1/8: 8.279
MPH: 86.201
1/4: 12.865
MPH: 106.093

My best of the 10/25/12 runs
R/T: 1.180
60: 1.946
330: 5.373
1/8: 8.219
MPH: 87.87

I was .02 behind my old run at the 60, but .06 ahead at the 1/8, for a gain of .08 in 600 ft. Also, the car's trapping 1.67 mph higher now.
I also have *MUCH* less seat time with the new combo than I did with the old when I ran the earlier passes.
I'm confident the car has 1.8 and maybe even 1.7 sixty times if I sew up the holeshot without breaking another axle... At least the SPEC clutch is fairly consistent when abused, unlike the hit or miss Centerfarce.

[The Dark Side of Will]

Looking at MIR for Test & Tune Sunday.

[Shaun41178(2)]

Try not to worry too much about ET and risk breaking another axle. 1.9 60's aren't bad. I would just try see what it will mph because that will truly show what its capable of and the power its making. The air will prob be the best this time of year to run good times.

[The Dark Side of Will]

It's supposed to be in the 60's over the weekend, so it should be beautiful weather and good for the strip.

[The Dark Side of Will]

Been looking up info on the GM Racing output flanges for the 4T65E-HD used with the Ecotecs in the early/mid 2000's. I've located a guy who has NINE sets of flanges on his shelf... He wants $280 each for the left and $310 each for the right. I could use them on The Mule just by swapping them left for right. That would certainly guarantee that the next thing I broke would be deep inside the transmission instead of an axle that's (relatively) easy to replace.

Those flanges are set up to take Porsche 930 CV joints.
Found this thread:
http://www.gt40s.com/forum/gt40-tech-po ... stion.html
That links to this drawing: http://www.gt40s.com/forum/attachment.p ... 1266753670
That shows an adapter to bolt Porsche 930 CV joints to an Audi transaxle. The Porsche joints appear to have 6x10mm bolts on a 94mm circle... I'll have to measure the BMW E34 540i 6 speed axles I have in the shed to see what their mounting bolt circle is... I might be able to come up with some bullet proof axles pretty cheap.

http://www.realoem.com/bmw/showparts.do ... g=33&fg=10
RealOEM lists "94MM" in the comments for the E34 540i 6 speed output flange... that might refer to the bolt circle instead of the overall diameter of the flange. Intredestating.

Of course, then I'd still be using GM's Type II intermediate shaft, so that would be my weak link. I do have an extra unit which will have cryo'd and WPC'd regardless.

[Series8217]

Will, did I sell you one or more of my intermediate axle shafts? I know I had one of each style, but I'm not sure if they're still sitting around in my parents' garage or what.