IRP shifter - input needed

[prandelia]

Is/has anybody been using the IRP shifter for some time on track/racing? I'm trying to understand if a shifter like this (that is super short/fast) causes accelerated wear on the FRS gearbox/synchros? The shifts are so short, you can't really "slow" down shifting with an IRP.

The gearbox is already a weak point, would be nice to hear if anybody else has been using one for a while without any issues that they know of, so I can feel confident in investing more money in upgraded gearboxes from Jacks. My motor/trans/diff are already solidly mounted, so going to a chassis mount isn't a problem.

Thanks for any input.

[NoHaveMSG]

I'm over 2 years on mine and no issues. I find that I need to be more deliberate with my shifts. Using one for the first time kinda messes with your timing since the shifts are so much shorter, but you get used to it.

No noticeable change in syncro feel.

[DarkPira7e]

Tough to pin a direct cause on it, but I know someone who installed the IRP shifter and within months he was having engagement issues. He eventually replaced the transmission

I don't know if he re-installed
No idea if causation was that the transmission had existing damage, or if the installation was causing a problem.
@Setgo

[prandelia]

Thanks. I've raced others cars with IRP shifters, so I know exactly what they feel like and effort involved, they are phenomenal on track, but every gearbox is different, and ours doesn't inspire confidence so I'm not looking to make an update that may substantially hinder reliability.

It's just such a hard effect to try and pinpoint.

I think it's important to note that my car is 100% track, and when 100% of your upshifts are at 7500 RPM, or high RPM downshifts, that is a massive difference than street driving with occasional canyon driving, or WOT rips in a single gear. So if somebody has had one for a few years and this is their typical use, it may not be very relevant, although I appreciate it as a data point in general.

[NoHaveMSG]

I have about a dozen track days on it during that time.

[prandelia]

Originally Posted by NoHaveMSG

I have about a dozen track days on it during that time.

[Setgo]

Hey so DarkPira7e tagged me, so I did experience lockouts, constant readjusting, and synchro issues. Its possible that the irp made my synchros wear faster but I have many supporting mods to make sure my transmission moved as little as possible, and that the irp was always in spec. My verdict that there were two factors that made my shifting experience terrible. It was my clutch (cause of lockouts possibly) and my transmission fluid. Everyone swears by this product for transmission fluid but I swear it's the culprit behind my gears wearing out.

I did buy a new transmission like he said, I'll be running redline instead, and buttoning everything up. Hopefully this all fixed it. We will see. But I feel that the irp wasn't the biggest factor. It mounts to the chassis and barely moves, but I did have to adjust the set screws more, but also that's when I changed fluids too. Ack, so many factors.

[Ohio Enthusiast]

Originally Posted by Setgo

My verdict that there were two factors that made my shifting experience terrible. It was my clutch (cause of lockouts possibly) and my transmission fluid. Everyone swears by this product for transmission fluid but I swear it's the culprit behind my gears wearing out.

I did buy a new transmission like he said, I'll be running redline instead

That's interesting, and seems to jibe with the somewhat common claim that since Motul is a GL-5 fluid it's incompatible with brass synchros, despite Motul's claim of a GL-4/GL-5 rating and peoples' experience of it. How long did you use the Motul and how long until problems started and the transmission failed?

[Setgo]

Originally Posted by Ohio Enthusiast

That's interesting, and seems to jibe with the somewhat common claim that since Motul is a GL-5 fluid it's incompatible with brass synchros, despite Motul's claim of a GL-4/GL-5 rating and peoples' experience of it. How long did you use the Motul and how long until problems started and the transmission failed?

So I installed it at 88k miles and road it to about 108k, so 20k miles roughly. I was constantly adjusting the irp because I thought that's what it was. But after contact irp they said it shouldn't be the case. They are even sending me new bushings, etc because maybe the just the slight used washer may account for something. So I switched over to redline mt90 because it is gl1, gl3, and gl4. So we will see. It is worth noting that after dropping my transmission that my clutch also had many hot spots and had 20k miles on it too. It was an ACT clutch. Love the company but I went with exedy this time.

[churchx]

Slight offtopic. I too switched to redline & it improved subjective gear switch feel (w. stock shifter though, not IRP, and with also perrin gearbox & tranny bushings) .. but MTL, not MT oil.

[Ohio Enthusiast]

Originally Posted by churchx

Slight offtopic. I too switched to redline & it improved subjective gear switch feel (w. stock shifter though, not IRP, and with also perrin gearbox & tranny bushings) .. but MTL, not MT oil.

Doesn't our transmission require 75W90? Why did you go with the MTL (which is 75W80)?

[churchx]

Well, one thing is single-out viscosity parameters at temps, for gearbox oil also it's frictional parameters matter for synchros to engage well. While true, manual of ours states should be GL-4 75W90, it's not as if all the rest are unusable. For engine also after all not just one 0W-20 possible, but manual mentions also 5W-30. And some do fill different, for a bit higher pressure on tracked car.
At some point in past esotericperformance tried out multiple oils (#1 #2) and had best results with Redline MTL (+GB/TM bushings), my experience was similar (have tried OE oil (obviously), Motul 300 (of stock-ish 75W90), Verus's suggested Torco Synchrotech MTF, and Redline MTL 75W80. Best shifting feel was with later. Motul & MTF felt slightly better then OE, but MTL+bushings felt best).

[EndlessAzure]

I've used a short throw shifter for about 3 years now (TRD).

I didn't notice any significant change with shifting over that time, with track days and 60k miles of daily driving & heel-toe shifting.