Review of Guard Transmission on GTS (GT)
 

After almost 1 year in the making, I have finally installed the following gearset from Guard Transmission on my 718 GTS.
Gears 2nd through to 5th. This comprises of:
- New mainshaft with fixed 1st & 2nd
- 1st ratio 3.31
- 2nd ratio 2.25
- 3rd ratio 1.60 (20:32)
- 4th ratio 1.286 (21:27)
- 5th ratio 1.083 (24:26)

As expected, the quality in machining and finish is top notch from GT.

Install took a few weeks, mostly due to the roller bearing on 2nd having a cracked plastic casing on re-install, thus sourcing a replacement part from Germany. A note on this is to be very careful as Porsche don’t supply any transmission parts for 982 yet, however fortunately VW/Audi share some parts on the transmission.

Why I decided to change the ratios:
I found 2nd lazy at lower city speeds in terms of pick-up and go. I know many say to use 1st more as a functional driving gear, however these cars don’t eagerly shift into 1st over 20kph. A lower 2nd would add more torque and pick-up in city driving.
The rev drop delta was too high on all shifts, but especially 2nd to 3rd . Even on a red line upshift 2nd to 3rd sees you drop out of the peak torque band.
These cars have such a great shifter, but with the long factory gearing I typically sit in the canyons in 2nd or 3rd. I found that I constantly short shift just to get additional engagement.
Personally, the top speed of 2nd wasn’t a gripe, but more the big deltas in revs drops on upshifts
I didn’t want short ratios, rather normal ratios.
I went with GT over others because I felt the 2.25 2nd would be a better option for my use case.
I did look at CWP final drive change instead, but many experts warned me to stay away from these on Porsche’s due to weakness.


The result:
The car feels considerably quicker and responsive. Not only due to the increased torque, but also being in the correct rev range more often. It is a total game changer mod. I have tuned many turbo cars such as BMW M-cars to +15-20% power, and I’d have to say that this gearing change is comparable as to how much quicker the 718 feels.
The whole drivetrain now feels 'tighter' and there's a feeling of less 'give' or cushioning.
Accelerating through 2nd>3rd>4th is now the pinnacle experience. The shift intervals are spot on and upshifts from 7000 land right in the sweetspot of 5500-6500. It is an addictive experience rowing the gears on any open section of road. On canyons and B roads, I am now using all of 2nd, 3rd, 4th , and even if I short-shift, I still land in the power band. It is a blast to drive now, up & down the box. Immensely engaging experience.
Rev match works perfectly.
The 2.25 2nd ratio does make the rear slightly more lively, but not in any way that is overwhelming. I feel that is better this way.
I had to adjust to change more quickly as shortly after one upshift, the next is only a few seconds away. No more long waits while the tach climbs.
The gap on highway driving between 5th and 6th (OEM) is fine and I have found myself actually using 6th now, where as before there was no need to really use 6th due to 5th being so long.
I wouldn’t describe the gearset as even a short ratio setup, but rather that it is now normal. These cars should have come from factory with these ratios.
Noise. There is certainly a slight increased amount of gear whine. Nothing extreme, but it is noticeable, especially at lower speeds on deceleration in 2nd. It is really only in 2nd and 3rd that I notice the noise, and then only apparent in slow moderate city driving between lights etc. Under acceleration I don't notice it, and nothing compared to open exhaust valves or tire noise in these cars. Just be aware that there is an added mechanical sound.


Conclusion:
If you plan on keeping the 718 for years, then 100% worth it. My GTS is likely my ‘forever’ car given the impending EV era. I feel it has transformed the car into the perfect analogue modern sports car. It is a game changer and well worth the cost when considering it to cost/benefit of spec’ing LWBS or PCCB 😉.
If you get the chance, go and drive a 718 with shorter gearing. I pretty much guarantee you’ll put it at the top of your next-mod list.

For the gears, contact Matt at GT (https://www.guardtransmissionllc.com/) or one of GT’s agents such as Alex at Sharkwerks. Matt is extremely helpful and knowledgable.

Cost:
Parts around $7500 USD
Install (will vary) : $4000 USD


I’ll add a POV video in a few days.


https://cimg7.ibsrv.net/gimg/rennlis...5b82e20384.jpg
https://cimg8.ibsrv.net/gimg/rennlis...48d337b6f6.jpg

:burnout:

Looking forward to your video.
thanks for the informative write up,

I would love to see the acceleration difference demonstrated through a data logger.

thanks for the post

Thanks for the write up, and for shouting out Sharkwerks. They're pretty close and were who I was hoping I could deal with.

nice review - looking forward to the video!

Will try sort out a video in the next few days, just swamped in work this week.

I should add that I am really enjoying this gearing more and more. The instant pickup in acceleration in 2nd and 3rd is addictive. There's no waiting as before. My biggest gripe with OEM gearing was if for example I was in 2nd at 3000rpm and went WOT, then there was a lag. 2nd gear is now brutal in terms of acceleration, as are the subsequent upshifts to 3rd and 4th. Its really woken the car up and feels incredibly fast.

As promised...

Why do you change gear at 6 and 7k revs, it’s like having a 300bhp car ?

Because I can. I'll let you work it out.

Great report!

I just received my Cayman GTS 4.0 with the Deman shortened 2-5, and I can't believe how much it improves the car! It is an amazing modification, this and a good exhaust completes the car.

Yes, game-changer mod. I really don't know anything that compares to this now, other than a GT3 Touring.

After 1000 kms now, these gears have really quietened down. If gear whine was apparent after the install, it is virtually barely noticeable now.

Is your car tuned? Sounds good too 😎