Sequential Gearbox Upgrade

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PostPosted: Tue Mar 29, 2022 4:50 pm
Yeah, to be fair, I think I had one gearbox failure, one clutch failure, and one axle failure in ~10 race weekends. Then I bought a newer car and had the fuel cell and timing gears fail in about 6 races last year. Don't stand near me if there's bad weather. Other people have run cars with just normal maintenance for years with no significant trouble.

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Joined: Tue May 01, 2012 9:22 pm
Location: Framingham, MA
Chassis:
95, 950
PostPosted: Tue Mar 29, 2022 6:02 pm
We all have different shift timing with regards the the clutch. I wonder if there is some pattern to fast light clutch/speed shift no clutch and failures. I don't think we would be able to tell without putting data side by side and also getting clutch line pressure.

I am a slow deliberate clutcher (at least that's what the data says) and it took 1,100 laps and 3,400 miles to wear out something in tranny and mess-up the 3/4 shift. I wore out a clutch disk or two along the way, and probably a rebuild at 2/3 of the distance would have saved a race weekend.

I have four weekends on the current H's and am not sure when I will do the upgrade once the unit arrives.

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Joined: Wed Oct 07, 2015 8:44 am
PostPosted: Tue Mar 29, 2022 8:44 pm
36 race weekends over 5 years, about 11,000 track miles. Started with a fresh rebuilt box. Had two failures costing a total of $2,500. Feels like a reasonable cost to play.

Issue are very driver-dependent, but admittedly some casino elements involved.
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Location: Augusta, GA
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494
PostPosted: Tue Mar 29, 2022 9:51 pm
Remember - Another of the factors contributing to broken gearboxes was the influx of straight cut gears that were not heat treated properly, and then a period of getting a weaker set of synchros for a time.
Kurt Breitinger
SEDIV #28
Chassis 494
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Location: Greenwich, Connecticut
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860
PostPosted: Thu Mar 31, 2022 9:34 am
Same here. The Mazda box in my car had two repairs over 100 hours of GEN2 and GEN3. Standard (helical cut) gears and synchros.

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Location: Oregon
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404
PostPosted: Sat Apr 02, 2022 4:02 pm
We are on our second transmission with Gen3 in 4yrs after conversion

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PostPosted: Mon Apr 04, 2022 2:48 pm
Just completed my first weekend at Summit Point with the SADEV. There were three cars running SADEV for the first time. One stalled by a CSR and the other two installed by car owners. No issues with any of the transmissions other than a leaky inner CV boot. Everyone used autoblip with varying levels of blip.

Definitely requires some getting used to. It's not going to shave seconds off your lap but it make battling a fair bit easier.

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PostPosted: Tue Apr 26, 2022 7:33 am
Tidbit for SADEV usage. At least two of us at Summit Majors were having issues with downshift (5-4 and 4-3) at points. The gearshift just would not move forward at all. It was very intermittent.

We sent ECU data at Enterprises and the response was eye-opening. If your engine is "pushing" on the trans, it's not going to downshift. If it is "pulling" or "dragging" it will. So, what we were doing was applying excess throttle while trying to downshift. The auto-blip doesn't happen until the shifter starts to move, so it does not impede downshifts. I'll know for sure if/when I get the car out again, but I believe Brother Davies until proven otherwise. This is also a reason to choose auto-blip rather than try to do it yourself.

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PostPosted: Tue Apr 26, 2022 9:22 am
Yep, if you have the blipper and are getting some throttle with the brake (big shoes or both feet active at the same time), it will fight you mightily because the gears are loaded up by the engine fighting the brakes. If you're doing everything right and the blipper is properly adjusted it's low effort because the gears will change from being loaded by engine braking to being unloaded when the engine revs, the selector can then move to the next gear, and while the the trans is between gears the engine will freely rev up to match the new transmission speed. BUTTER

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PostPosted: Fri Jan 13, 2023 7:05 pm
Question - How long does it take Enterprises to ship a Sadev once the full payment has been made?
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