Hello,

I just wanted to let you know that we have finished production of our new ring and pinion set and will be shortly releasing them for sale. What we have made is something that's not currently offered on the market. The ratio is 4.125 with a toothcount of 8:33. This is a bit shorter than the 4.00 ratio used on the Cup Cars and should provide a significant increase in longevity. Furthermore, it should provide a cost effective option for a lot of people who just generally want a shorter box without commiting to regearing the car for a specific track or group of tracks.

Now, as you probably know, Porsche has changed the "stock" ratios on these cars about as often as most of us change our socks. Furthermore, if you've got an RS, you had the option to gear it special in the first place. As such, what follow are some generalized numbers of how things would change, and for my example I have used the G96/96 gear ratios. I have also used an 8000rpm redline and 26" tire size. These things are going to change by year and by things like track versus street tires. A difference of 500rpm or .5" either way can change things by 5-10mph, so keep in mind that if you want to know EXACTLY how it will impact your car, we'll want to run a chart specific to your car and usage.

That said, removing the 3.44 stock R/P and putting in this one will drop the 210mph 6th gear down to about 175mph. 5th gear, which was previously good to 179, and likely kept you from ever using 6th on all but the longest of tracks, now tops out at 150mph.

On the bottom end of the scale, this will also often allow you to stay in 3rd gear and not shift into second gear, which you may currently have to do for certain corners. The top of second is now 70mph versus 83mph with the stock R/P. As low as something like 60mph, you'll be able to stay in 3rd gear and not shift off the main 3-4 shfit axis. 2nd gear is the achilles heel of this gearbox on the track and if you can avoid downshifting into it, you're gearbox will last longer.

However, there's always tradeoffs with this sort of thing. If you drive your car on the highway alot, your cruising RPMS will be higher. 75mph is now around 3400rpms instead of 2900rpms or so. Furthermore, everything in the box is now always spinning faster. Things will wear faster as a result, but most people are willing to accept this as the price for more performance.

Lastly, I would like to try and keep this thread more focused on the technical side of the product and what it will do for you. Though I know people will want to know the price of these parts you're gonna have to wait until we post a classified thread. But there will be a 6Speed special price. You've just got to wait for it. In the meantime, I'd like to open this up to discussing how this modification might benefit you, and discussion of specific applications and tracks that help you to understand just what's going on here.

Regards,

Matt

 

Very interesting product.

How does this compare to the new R&P in the 7mk2 RS. What ratio is that in comparison?

Any chance of a table showing original gearing vs speed and new gearing vs speed with this one? Personally I'm interested on a 996 GT3 with 18" wheels. The ratios never changed on any of the 6 GT3s or 7mk1 GT3 as far as I know, so shouldn't be hard to do (and leaves me confused about your comment saying they changed lots as I don't think they ever did for the road cars).

Also how much does this change acceleration?

 

Hello Dan,

The new RS ratio is a 3.89,( a 9:35 toothcount I believe) so it's still taller than the Cup Car 4.0. But they gave it a shorter 5th and 6th gear in response. This one is shorter than the Cup Car version, but not as short as the old 7:35 that was so popular in Europe a few years back.

The numbers I put above are based on a 2004 996GT3 gearbox. You are right that they were consistent early on. It's the last few years that they've started to move them around a bit. The primary reason I chose to make the example of the earlier ratios (like are in your car) is because those are the gearboxes that are most likely to be in need of a refresh and service.

If you want to shoot me a PM with your direct email address, I'll send you an excel based gearchart showing you what your car would look like with this ratio in it. Just be sure to include what you use for a redline and your exact tire size. There's guys running 305/30/18's and guys running 335/30/18's. Those are two different diameters even though they are both 18's. Unfortunately I don't have a clue how to post an excel spreadsheet to a web forum.

How does it change acceleration? The car will be quicker in every gear. In a track application, you'll notice it most in 3rd, 4th and 5th. Your shift points will change on the tracks that you already know. You'll need to relearn the places where you drive and what gear to be in at what location because you'll often be in a gear higher than you were before.

 

ok so standard tyre sizes on 996 GT3 are 295/30/18 & 235/40/18. I wasn't sure about your numbers as I had heard from those racing 6cups at the ring that their vmax was 170 but I guess they have different ratios so maybe not a straight comparison. The appeal with seeing a list is being able to quantify whether it is going to make 1st + 2nd a bit pointless?

In terms of acceleration benefit, is it possible to quantify the impact in 1/10ths of a second?

Sorry for the cross-exam

 

Hello Dan,
There's no need to apologize at all. I wouldn't have started the thread if I weren't open to questions and discussion.

I'll start with the hard one. No, I cannot give you numbers within a 10th of a second regarding how much faster you will be. This ratio has never been used before, so I have zero empirical data from customers that I can draw on. I imagine that there's some math and calculations that would allow you to guesstimate the differences, but it's a bit over my head. I am not engineer and after my second semester of university calculus they required for my degree I promptly forget everything they ever taught me in the previous 18 years of schooling. So it's possible, but unless one of the resident engineers wants to pop into this thread, and do some real math I'm not going to be able to quantify it for you.

However, what is more likely is that someone who is already running a 4.00 Cup R/P will comment on the changes that one made on their car. It's been a somewhat popular modification over the years.

You are correct that comparing what a Cup Car does on the ring isn't really useful data here. Not only do they run the 4.00 R/P but they are specifically geared to that track. According to Porsche's own published suggestions, for running The Ring, they would advise using a 0.96 6th gear. That's a shorter 6th gear than has ever been put into a GT3 street car. The closest a GT3 has gotten to that ratio is the 0.92 used in the mk2 997 GT3.

Porsche makes 15 gear ratios for 5th and 6th gear. We make 32, overlapping with the OEM ratios, with additional taller and shorter ratios at either end, as well as a few in between some of the bigger gaps between the OEM offerings. The ability is there to micro-adjust the ratios to exactly what is needed for a specific application. So when a Cup Car hit 170mph on The Ring in 6th gear, it's probably at around 8200 or 8300 rpm using every last bit of the gearing and leaving nothing on the table with respect to performance. These are cars where the telemetry they carry does allow them to measure this stuff to the last 10th of a second and the teams that win spend a lot of time analyzing this stuff and datalogging. If that kind of performance and application is something you want to explore I can definitely consult with you on it.

You bring up a good discussion point by mentioning 1st and 2nd gear with this set up. That's one of those compromises that I mentioned above. However, it's a little of both a benefit and a liability. People constantly complain because 2nd gear is fixed to the mainshaft and they can't make it shorter without buying a different mainshaft with a slide on 2nd gear. Depending on the source (OEM or our parts) you're looking at several thousand dollars or more. The short ring and pinion solves that problem, but it does do it at the sacrifice of 1st gear. Stock, 1st gear is about a 50mph gear. With this short R/P set it becomes a 40mph gear. It's still workable for the street but it's gonna go by really quickly and if you drive your car in town a lot it may bother you. But for people tracking these cars, it will likely be a sacrifice they are willing to make.

Another member has offered to take my gearcharts and convert and host them, so I'll be sending them over to him this evening. Check back in the morning and you'll get more of a visual how this plays out. In addition to stock G96.96 and G96.96 with our short R/P in it, I am going to send him the 2010 GT3 RS with 3.89 R/P ratio.

 

subscribed

I did the 4.0 r&p in my former 996-3 and it was well worth it on my local tracks

first gear is short and as matt said I was willing to make that sacrifice and would do it again...

I will play with my new to me .1 rs in stock form but my thoughts are that this 8:33 is in the near future.

this is the poor mans re-gear

 

Hello,
I hope to be able to post charts later today. However in the meantime I wanted to attempt to give you some numbers comparing this to a 2010 GT3 RS gearbox. Hopefully this will format reasonably well. I used 8000rpm redline and the 295/30/18 (24.97") suggested above.

Gear 997RS 996w.8:33
1st 40mph 37.7mph
2nd 67.4mph 67.0mph
3rd 93.2mph 92.3mph
4th 118.8mph 118.4mph
5th 143.9mph 144.1mph
6th 172.6mph 168.8mph

As you can see, on pretty much every gear except 1st and 6th, they are within roughly .5mph of each other.

 

Here you go...

 

Matt,

I understand the reasoning behind making it an odd (not divisible by 8) number, but why not 8:31 (3.875 ratio)? Or is it just "more spinning, more wear?"

 

The 3.875 ratio wasn't ever really considered because it's just too tall. That's taller, not shorter, than what we made, and ours is going to make the internals spin faster, so that wasn't a motivating factor. By going with the 4.125 we have a ratio that's partway between the 5.00 (7:35) and the 4.00 (8:32) ratio that the Cup Car owners are used to using. This way they don't have to buy a whole bunch of new ratios to keep servicing a car over time. When they wear out a ring and pinion, they'll be able to slip this in as a direct replacement and regear the box with ratios they already have in their trailer as spares. It's that microadjustability that I mention above, and most of the top raceteams have a couple of dozen spare ratios on hand to regear the box for whatever track is next in the series they run.

We've got a certain philosophy around our parts and our business. The majority of our customers are racers and we see ourselves as a manufacturer of motorsports parts. We understand that there are street drivers who will recognize the value of our parts and purchase them for street or weekend track day (DE) performance improvements. But that's not our target market. Our target market is dedicated racecars at the recreational and professional level. While this is a great "poorman's regear" as was mentioned above, the majority of this production run will go into actual Cup Cars that wore out their 4.00 R/P and can buy our replacement for about 15% less than it would cost them to buy another OEM 4.00.

Furthermore, a smart businessman doesn't aim for a market that's already populated. With the 2010 RS using the 3.89 ratio, which is very close to the 3.875, there's already going to be an OEM option for people who want to go a little shorter than stock but who still really want a street car for weekend track use. That factory R/P when it becomes an available service part in a year or two will be a great option for a lot of people. So, while we will also sell that R/P, just like we already sell the 4.00 and 3.44 R/P sets, if we are going to spend the time (a year) and the money (more than I care to admit) bringing a new product to market, we're going to make it unique. So that's what we did. There's no other ring and pinion on the market that will offer the same performance that this one will. It is a Guard Transmission exclusive product.

 

In case anyone out there can't open the pdf files..here they are converted to jpg files that will display fully...interesting stuff

first is the stock 2004 996 GT3:




next is Matt's 8.33 r&p



last is the 2010 GT3 RS with 18" wheels/tires

 

Interesting reading Matt... top marks again with product.

 

Wow. Those are big. Too big for my 14" screen on my laptop. But thank you very much for your help on this Chuck.

And thanks Stevo. We're always trying to put out the best most cutting edge parts that we can.

 

I'll see if I can shrink them....ahhh, success

 

Great philosophy.

I've been contemplating doing the 4.0 R/P but was hesitant due to wear concerns...an 8/32 always lands in the same place each and every revolution.

This seems right up my alley.