Sequential Gearbox Upgrade

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PostPosted: Sat Feb 27, 2021 12:27 am
10k, 12k it doesn't matter. We have all of the available case inventory tied up with our race cars. There is one ford mondeo transmission available on the interwebs: https://www.ebay.com/p/18023803205 If you want to source parts for a transmission that hasn't been in production since the early 90s you go right ahead and keep the old box. Hell I'll give you mine when it's all said and done.

I don't know about you guys but the race car I want to be investing in is the one where the series, engineers, tests, and sources parts so I don't have to think about it. I want a reliable machine with low maintenance. I don't want to go pull the tranny every 5 weekends at a 1500-2000 cost to make sure I don't have mechanical failures. I want to nut and bolt, fluid check, safety check and go flog on the thing for hours!

I understand the capital outlay is a big deal but the class needs this change!

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PostPosted: Sun Feb 28, 2021 12:25 pm
My son drove a sequential box SRF3 at Hallett yesterday. The sequential is/will be a game changer. The sequential kit is EXTREMELY well designed. The package is impressive and SRF3's will be a few seconds a lap faster. In racing $12,000 is not bad for a second a lap IMO. Most racing disciplines gaining a second a a lap is far more expensive. We are excited about the upgrade and cannot wait to get a sequential.

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PostPosted: Fri Mar 05, 2021 5:12 pm
so, the sequential won't have an over-rev protection for downshifts.. for when inevitably make that mistake ?
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PostPosted: Fri Mar 05, 2021 6:22 pm
I guess ROI would be recovered by not blowing up two motors on the 3rd to 4th upshift that turns into a 9,200 RPM downshift to 2nd! The other weak link today is the clutch, so not sure if that's cured by this solution (hopefully). Finally, if it has proper gear ratios, that would be the ideal scenario. Fifth gear is pretty much useless at Sonoma/Laguna Seca/Thunderhill, and ratios don't fit the powerband (maybe raising the RPM limit would be possible if there's less exposure to missed up-shifts).

Is this a five or six speeds box? Is it's strictly mechanical, or will be electronically controlled (e.g. downshifting two gears and having the electronics manage is correctly). And, finally, will it ignore that "oops" moment when you "pulled" instead of "pushed" on an intended up-shift out of the RPM limit? 6-speed might be helpful in better managing the power-band and safety margin on down-shifts. Sounds a lot from the description that it might look like this: http://www.swrmotorsport.com/ST75-14.html Can anyone confirm, or is this a "super custom" job?
Bob Breton - SRF 51 - San Francisco Region
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PostPosted: Fri Mar 05, 2021 6:45 pm
As a newbie coming into SRF3 this year... but having been involved with other classes of cars, one of which was a sequential GB I know that it will indeed be a game changer... but I agree with other comments that the cost needs to come down or SRF3 will price itself out of its own league just like many other classes of cars have in the past... I could see a SGB for 7-9K vs. 12k.

It would be nice to see a couple of the CSR's chime in here on this issue... ;) I've seen one on an engine in a shop but that's about it.

Doug
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PostPosted: Fri Mar 05, 2021 8:35 pm
Bob, et al. The pictures I have seen and what descriptions forwarded to me gave me the following:
It is a 6 speed custom fitted sequential gearbox, mechanical shift as we would have to run a cable from it to a new style shifter. There seems to be some electrical handshake with our ecu as it needs either a new one or reprogrammed for this Sadev tranny. I read that the 6 speeds were required in order to fit the gearbox in our current engine bay. The first gear is merely to get our cars going from a standing start (like my old Karmann Ghia). Haha. It will handle 180 HP, robust enough hopefully to not need the current rebuilds. Supposed to reduce overreving issues due to missed or wrong shifts. The 6th speed would be useful at Daytona as the current 5th gear topped out there. Early reports paired it with a fly by wire new throttle body but I don’t know if that is the case any longer. New rear axles are also required.
Will be interesting as the a season progresses to see them in action. 8-)
Mark Fick
I'm pretty confident my last words will be 'well shit that didn't work'
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PostPosted: Sat Mar 06, 2021 4:09 pm
From the photo posted on Facebook in the SPEC RACER FORD forum, I can see that it appears to be a custom case, based on the position of the three point mounting bracket (assume to fit the existing transmission frame mount position), with the rest looking pretty close to the ST75.

Wonder if it will it have a limited slip diff, as well?

https://www.sadev-tm.com/media/st75lw_transverse.png

I'm going to bet it's going to be closer to 15k, especially if they update the throttle body/drive-by-wire, plus the cost of new halfshafts (clutch upgrade?).

Doesn't look like it will be any easier to do a transmission/engine change, though...
Bob Breton - SRF 51 - San Francisco Region

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PostPosted: Sat Mar 06, 2021 6:15 pm
I vaguely recall Davies mentioning that it would open-diff, but I would not mind limited-slip at all! I've gotten spoiled with it in my street cars so it's always disappointing to go to 2nd gear in a tight corner in the gen3 and have all that grunt just go up in smoke.
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PostPosted: Sun Mar 07, 2021 11:47 pm
FWIW they are following a testing year process similar to the way SRF3 was tested. Multiple CSRs have the gearbox in cars and multiple drivers are running it this year. Drivers do not get points for finishing positions/placements.

From what I heard, if approved, the intent would be to make it a new SRF4 class, just as SRF3 was made distinct from SRF. Note that the rapid uptake of SRF3 enabled(????) relegating SRF to Regional only status after a few years. Given that SRF3 is one of the more popular SCCA classes, one would hope that it stays around unless/until SRF4 really takes off.
Todd Butler
OR/SFR Region

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PostPosted: Mon Mar 08, 2021 12:07 pm
I'd be disappointed if the class fractured again, but given that the upgrade might end up costing more than I originally paid for my car 15+ years ago I can understand that folks are reluctant to spend the cash. There's also the logistics of building hundreds of new transmissions even if it were significantly less expensive. On the flip side, there is the benefit of having two classes to potentially participate in at the runoffs for a year or two :)
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