300WHP Supernatural 3.XX Coming Soon! (Page 49/54)
La fiera MAY 29, 09:44 PM

quote
Originally posted by Notorio:

Now that you've got this build done, and before you start your next build, can you please make a list here of all the mods that you made? The post is 12 pages long now and I'm too lazy to go through with a fine-toothed comb to make the list myself



That would be too easy! Like installing an LS or a turbo!!
La fiera MAY 30, 06:55 PM

quote
Originally posted by Notorio:

Now that you've got this build done, and before you start your next build, can you please make a list here of all the mods that you made? The post is 12 pages long now and I'm too lazy to go through with a fine-toothed comb to make the list myself



https://youtu.be/jqzdOPSqLbg

This will help you!
La fiera JUN 27, 10:13 PM
https://youtu.be/oFQFaqonhk4

!

The 3.7L Supernatural snapped a brand new axle. Good thing it's under warranty! I installed these new ones with the engine so they have no miles. With the 3.4L would take several dyno sessions and several mileage but I was stomped at how fast this one snapped, maybe 20 miles on it? Will, how many axles I've broken? I lost count!


pmbrunelle JUN 27, 10:59 PM
Maybe it's time for drive-by-wire! Maybe there's a happy medium where the throttle response is slowed down enough to reduce the shocks on the drivetrain, but not enough to slow you down on the track.

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As long as you're using the F23 transmission, I guess you're stuck with those splines. Maybe you could get the tripots cryo-treated?

Otherwise, I've been wondering about the benefits of an undercut at the end of splines:


Is there room for a bigger undercut, and would a bigger undercut be beneficial?

I have this exact question for a splined shaft in a work-related project; if my work colleague has some time for me in the coming weeks, I'll ask him to do some FEA comparisons of splines with/without undercut.

I think that cutting the undercut larger would be relatively doable on a lathe. From memory, Fiero tripots have centre holes on both sides, so it would be easy to get the tripot set up between centres.

[This message has been edited by pmbrunelle (edited 06-27-2022).]

La fiera JUN 27, 11:20 PM
I was thinking about the cryotreating also!
Trinten JUN 27, 11:54 PM
So it looks like you are shearing off the flange stub?

If that's the case, you could talk with a group like G-Force to see if they would machine you a custom set of flanges that will connect to the stock half-shafts. Then if you do bust the half-shafts, you can work with them or Dutchman to have those made.

I don't know if any companies made stronger cv axles for any cars that came with the F23, but that might be worth some checking into as well?
La fiera JUN 28, 05:17 PM

quote
Originally posted by Trinten:

So it looks like you are shearing off the flange stub?

If that's the case, you could talk with a group like G-Force to see if they would machine you a custom set of flanges that will connect to the stock half-shafts. Then if you do bust the half-shafts, you can work with them or Dutchman to have those made.

I don't know if any companies made stronger cv axles for any cars that came with the F23, but that might be worth some checking into as well?



Thank you Vince! I'll give them a call today!
Will JUN 29, 10:18 AM

quote
Originally posted by pmbrunelle:

Maybe it's time for drive-by-wire! Maybe there's a happy medium where the throttle response is slowed down enough to reduce the shocks on the drivetrain, but not enough to slow you down on the track.




It's not throttle response... it's dropping the clutch on sticky tires.

https://www.fiero.nl/forum/.../000121-18.html#p708


quote
Originally posted by 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.




Note that mine wrung off directly through the splines rather than at that undercut. The splines remaining on the cup are angled, demonstrating that the shaft twisted before shearing.
I had a hardness check done, but I'm not sure it was done correctly, as the results are REALLY low (like RC26 low... I'm not sure they could actually be that soft and still do the job)
La fiera SEP 17, 10:22 PM


Finally got it to where I can drive it to the dyno on its own power. After fixing the fuel flow problem, the ECU setting problems and other problems I was able to Dyno it. But driving to the dyno and at the dyno I had a problem, it didn't wanted to go over 5000RPMs. It felt like it was hitting the rev limiter even though I set the limiter at 9000RPMs. I did log every pull so I got plenty of data to analyze.
This is the Camaro 3.4L bored out to meet 3.7L, same iron heads, no juice, super or turbo charger; all NA.

324WHP & 360WtQ @ 4900RPMs
Trinten SEP 18, 02:30 PM
Congratulations on hitting your goal!

You set out to find a way to do it, and to stay within the racing class restrictions. Thank you for sharing with us (here and on youtube) about the efforts and thought you put into making it work - right down to weighing valve train components!

Hopefully your spark issue won't be anything crazy. I recall seeing a few articles that got into the science behind different ignition systems, with a focus on coil packs. In short it seemed when you got into specialized territory like you have, there starts to be some "give and take" around picking an ignition system that best meets the range the engine will most often be running in.