IRP vs Coolerworx Comparison
 

Wanted to post a little review of the new IRP short shifter. Previously was only available for the 350z but it looks like IRP recently decided to make a mounting plate for the 370z. Purchased from DriftHQ on Black Friday.

Chassis mounted, similar in design to the Coolerworx. A few members on here have complained about the rattling from the Coolerworx and the difficulty when it comes to finding the source. I didn't have too much rattling - only at high RPM's and seemed to be intermittent. Was pretty content with it all things considered, but I believe the source of rattling on my unit was at the very bottom - the piece that connects to the linkage. Coolerworx has a little bit of play while the IRP feels solid.

• Price - Pretty close depending on where you buy it. Will be somewhere around $450-$500
• Build Quality - Similar compared to the Coolerworx. No complaints here.
• Ease of Install- Same as the Coolerworx. IRP does include longer screws to mount the base plate to your chassis (highly recommended, or risk stripping out the threads on your chassis).
• Reverse Lockout - Coolerworx has a collar, while the IRP has a button. Engagement on both feels smooth.
• Height - IRP is slightly taller and the fulcrum point is slightly lower. I would think that this would result in a slightly shorter throw but I can't tell the difference between the two. I was running a slightly taller shift knob on the Coolerworx which made the height on the two pretty much identical.
• Feel/throw - Both units felt the same in terms of reduction of throw from OEM.
• NVH - Coolerworx had an intermittent distinct rattle at high RPM's for me, while the IRP does not. There is a slight buzzing at high RPM's on the IRP due to vibration but is significantly softer compared to the Coolerworx. Driving at normal speeds (under 3k RPM), both did not rattle. Currently running a Z1 poly transmission mount.

Pros/cons/personal preference

• Reverse lockout - Coolerworx utilizes a collar, IRP uses a button that sits at the top of the shifter. I prefer the button over the collar.
• You can change out the shift knob on the Coolerworx. Although, thread size is M12 x 1.5 compared to the OEM M10 x 1.25. I ran a Likewise shift knob with an adapter.
• IRP is a bit cleaner IMO. The reverse lockout cable is fed through the cutout of the shifter so it is better hidden. The lockout cable of the Coolerworx runs from the collar and sits alongside the shaft of the shifter. This never really bothered me, until I read somewhere on a FB group pointing this out. It's bothered me ever since.

Nice review Alex!

I have a Coolerworx for my E36 M3 and it actually used an M12x1.5 thread pitch for the knob. Just FYI for anyone considering buying a separate knob for their Coolerworx shifter, def double check!
M12x1.5 was a major PITA to find knobs and extensions for.

I'm also a huge fan of the IRP button and cable routing. Just wish knob shapes were an option because I am fairly particular, though obviously the push button lockout makes swapping that out for generic knobs an impossible design. Would need to be something like how Raceseng can screw on different shapes to their cores I think.

Thanks for the correction! Edited

While Raceseng makes a lot of different knobs (I have about 8 of them) and has the M12 x 1.50 adapter, you might check out Shift Solutions. His are about a third the cost of Raceseng, are top quality and makes them with the M12 x 1.50 adapter. Here's a picture of mine.

I went with Likewise. Same concept - the threads on the shift knob itself are massive (M20 x 1.5) and you pick the correct sized adapter. Makes things easy from a manufacturing standpoint, and if you ever get a new car that utilizes a different thread size you can simply buy a new adapter.

Most of their shift knobs look dumb as hell (IMO) but I liked this one: https://us.wearelikewise.com/collect...ucts/the-ghost

Semi weighted (240 grams) and the top portion is delrin so it's not too bad in the summer. Will need to keep driving gloves in my car now that I'm running the IRP :rofl2:

WC Latheworks can also make shift knobs in the M12x1.5 thread pitch, and can also make custom knobs if you provide him with the specifics. I currently have one for my Coolerworx based off of the BattleCraft Hyper Teardrop design.

I have 2 of his shift knobs and can vouch for his craftsmanship!

Did you notice any buzzing or rattling with the IRP? I had a Coolerworx in my car with a loud exhaust system and the noises it made on decel bothered me too much! Made the car sound like it was going to vibrate apart. TIA!

There's a fix for the Coolerworx buzzing.

Coolerworx sent me the fix. It didn't fix it. Still buzzed/rattled like hell. I tried the Strike Fast and it was worse than the Coolerworx. I have an IRP that'll be going in when I install my new motor in a few months. The IRP will be installed with an 1/8" silicone rubber pad between the base and trans tunnel. That should help take some of the vibration out of the shifter (I hope) :icon17:

Well please keep us updated on it as I am genuinely interested in going back to a chassis mounted shifter if the vibrations are to a minimal. I'm hoping the IRP works well ��

What "fix" did they send you? (I'm just trying to find out why my homebrew fix worked but theirs didn't). Also, did you reinstall the rubber shift surround/dust guard that was used on the OEM shifter?

This updated linkage piece was suppose to be the fix. I didn't use the oem rubber dust guard.

It's going to be a while before my car's back on the road but I'll post an update. I like the design of the IRP. Very short reverse lockout cable. It doesn't wrap all the way around to the back of the shifter like the Coolerworx. And the cable runs through the center of the shifter shaft, unlike where the Coolerworx runs on the outside. The only issue, if it really is one is that it has a fixed shift knob, can't be changed out but it's a good shape so I think it'll be fine.

Here's the IRP and the silicone rubber pad I made for it

Only difference I can think of is 1) I reused the dust guard which could have an effect on reducing vibrations, and 2) instead of a plastic insert, I used the metal ones but used grease instead (also on the o-ring... pretty much just slathered the isht on everything that touched something else). No clue, but hope the IRP works out better for you.

I greased the crap out of everything too. I had big hopes that it would fix the problem. I think part of the problem could be metal on metal contact between the shifter base and trans tunnel. There's nothing to absorb the body vibration, that's why I going to try the pad on the IRP.

Had it on the car for a while. There is a slight rattle at higher RPM's but I don't think it's coming from the shifter.

After hearing the rattle, I pulled the IRP shifter out and took it almost entirely apart (the only thing I wasn't able to get off was the button - more on that below). Greased everything (grub screws, bolts, bearings, etc) and put the OEM shifter back in so I could still drive the car in the meantime. Still rattles with the OEM shifter at high RPM's, I believe it's coming from my linkage. Crawled underneath the car and shook the linkage by hand and that seems to be it.

The button sits on a bolt that threads into the aluminum body of the shifter. There is a grub screw holding this bolt down to prevent it from vibrating loose. Seems like this grub screw is over-tightened from the factory, because it bent the threads on the bolt that holds the button. I was able to rotate the button a few degrees by hand but with the bent threads, it'll never fully come out. From what I've seen on the FRS forums, the newer revisions of the IRP shifter has an o-ring around the button so I don't think that'll be a source of the rattle.

Putting the IRP shifter back together, I accidentally over-tightened the grub screw that holds the reverse lockout cable in place. This caused the end of that cable to push into the aluminum lever of the shifter and dent it, preventing the reverse lockout button from going down. It was a nice $177 mistake on my part :rofl2: luckily IRP was able to send me a replacement lever.

Overall, still happy with the shifter. Compared to the Coolerworx, everything just seems to be tighter in terms of tolerances and I prefer the reverse lockout cable being hidden. The piece that redondoaveb posted (replacement Coolerworx part) is a lot more snug on the IRP compared to the Coolerworx - mine had a bit of play when I took the Coolerworx shifter out.

Photo attached, don't over-tighten those 2.5mm and 3mm grub screws if you decide to take the shifter apart!

Hey Alex, glad to hear you got the replacement lever. Did you end up doing the rubber pad between the shifter base and the trans tunnel when you reinstalled it?

I did, but I ordered 1/16" instead of 1/8". Didn't notice much of a difference with/without it.

At least it didn't negatively affect it :tup:

Are you all running upgraded engine+transmission mounts? Sounds like a requirement for a chassis-mounted shifter. The relative motion between chassis and trans has to go somewhere.

I've tested CAE and Coolerworx in parked cars though and the direct engagement feels incredible.

Trans mount for sure. I have a great deal on a brand new IRP shifter right now

Which Raceseng knob do you like the most? Not on the IRP but on regular OEM shaft? or give me opinion on both.

zz

The Stratose would be a good one

I had the Z1 PU transmission mount, but I'm running the GKTech solid mount currently. Stock engine mounts, Z1 PU differential mounts and subframe collars.

My shifter is still rattle free.

I wish mine would have been. I've got the new Pro version I'll be installing when my new motor goes in

New motor, was there something wrong with the old (current) one, or just a need for more speed?

Just a rod through the block :rofl2: Going forged motor now

Pro version of what?

Coolerworx

Why did you switch from the PU to solid mount?

So stiffer transmission mounts are a must, but engine mounts could remain stock? I'm just trying to gauge how daily-driver friendly a chassis-mount shifter is. It sounds like not very :/

I wouldn't be able to answer that as I had the Z1 (PU) transmission mount a year or two before I had the shifter installed. I went from the Z1 to the GKTech (I added the MTec return springs as well) after having the Coolerworx for 3-4 years because I recall someone saying that it would help with the 1st > 2nd gear delay that our cars have. Did it help? Yes, a little. Was it the cure-all I was hoping for? No. Not only that, it also increased the cabin NVH, so it's definitely not for anyone who doesn't want a rowdy experience... I do, so it stayed.

That being said: solid/stiffer engine mounts are not needed, I'm still on stock and I've had the Coolerworx for about 5 years now. Solid transmission mounts are most likely also not needed, but since you're going to be under the car, I'd recommend going ahead and upgrading to a PU and be done with it.

https://www.vibra-technics.com/nissa...smission_mount

i have one of these and i noticed no increase in nvh.
must have IMO

Did it actually improve shift feel on a stock shifter? I’ve never really liked the shift feel of the Z.

These are the first hardened rubber mounts I’ve seen for our car. Ik some people praise the hardened rubber instead of PU or solid for NVH reasons.


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I got this one: https://www.torquesolution.com/370z-.../ts-tm-433.htm

No NVH on stock shifter. No rattling and better shift for sure. All in combonation with CSC delete, RJM pedal and new clutch.

i haven't tried a solid or PU to compare but it felt much batter after the upgrade.

Where did you buy this from? Thier website directly?

I asked them where they ship from and no response.