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.