mark kibort

we are not talking theoretical conclusion. we are talking about factual conclusion not correlating to a feeling of a few or even many drivers.
Now, you probably remember arugmentum ad Numerum. Just because a bunch of drivers get on a band wagon of dissatisfaction, doesn't mean it isn't all perception. ive broken many a "feeling" at the track and on the street in many areas of this subject. Im just trying to provide perspective and provide information so you can make your own decisions.

dont be so quick to bless... i come in peace. just trying to open a side of this that some might be ignoring. after all, this is 20 years of racing experience talking.. not some editor of a magazine taking cars out to play on the hyways. what we learn at the track IS valuable. (and in the lab too! )
thanks.. actually, it realy doesnt depend on the the track being longer or shorter, its the mix of turns and straights. I post a GT4 video that ive analyzed by a pretty decent driver running at laguna seca. if it were my car to be optimized, i would want a lower 2nd, and 3rd gear..... but at sears point or lime rock, just the opposite based on this level of performance (hp)

exactly and i get that point, unfortuntely some are not getting mine. im not disputing what you are saying at all. in fact, i have two versions of my race car, more radical in gears than what is proposed. (along with my street high per car) i know what you mean.. the shorter gears are more fun around town. ideal with some tracks and in my region, not good for optimization. with more power, that changes.. with less , it changes again. Lots of factors for pure performance. (not feellings)

Good honest post.. and thats all im doing... so, if you change the perception a little , suddenly the faster car on the track is fun on the street too, but you might have to drive it different.

mark kibort

Matt, tone it done a bit. for some reason, there are those that CAN think for themselves and understand im making aware a very often misunderstood set of concepts. i cant stress this enough, max power or the max power range is the best the car will accelerate, regardless of the gearing.

Here is a great example.. pretend this is your car.... look at the sspeeds and RPM... look when he shouldnt be short shifting and look when he doesnt. Look at the RPM ranges achieved. this clearly , for me, is a case of a car that could use a lower 2nd and 3rd, but how much would it help? AND, it would kill you in 4th if that was part of the plan... you see, its all trade offs. in this case, the gear box is pretty optimal. as i said, look even at the tight turns, there is no need for the max performance at turn 11 for example, in 2nd at 40mph, because of grip limits............. very usual on the street when going this fast... again again, if you are going totally straight, that little void between 1-2nd is not enough to worry about. we are talkin about a net gain of fractions of a second use of about 50hp.

watch and look at the RPM and speed ranges for a stock GT4 at the track. then, make comments how your gear ratios would change this. laguna is a GREAT track, because it does mimic how most drive on the hyways and hills when they want to go over the speed limit, which most often do. (hopefuly responsibly ..... just as your customer sharkwerks did in their video)

neanicu

Mark Kibort,I don't know your posts personally,I believe you normally post on forums I don't visit. I don't know your beef with others,I personally appreciate your perspective. I believe each individual is entitled to their opinion and should express it freely,as long as it doesn't offend others. So post away,no worries. Although bear in mind as I've said before,the GT4 is a street car...highly capable and very fast. It would be even better with shorter gears that allow you to shift close to redline and enjoy the upper range glorious sound : 2-3-4...heel/toe downshift 3rd,then heel/toe 2nd...back to 3rd etc...without doing triple digits.

Raghu

This discussion is fascinating but at times banking on hysterical. All good though. Significant excitement is generated from the technical and non-technical emotional charge involved in the thread. I have very simple thoughts in comparison to many with great experience and knowledge. As long as there are drivers that are faster in stock GT4 than I am, my goal is to improve my skill set and talents. I have not exploited the limits to what the car can achieve. I would like to push the limits of speed it can pick up and the limit of traction that it can offer to get my thrills. This happens with almost every sport I have played. In golf, people I play with always ask me what clubs I use when they cannot explain how long or how accurate the shot was. The clubs don't matter, the skill does and what you can do with any set up clubs depends on the talent of the golfer. When you think you know the limitations of the car, that is really the time when your own talent and ingenuity plays the biggest role and that would be something I would be proud of when I can pull something off that is impossible with a club or car. Like they say, it is the Indian and not the arrow that really counts.
Just sayin...

orthojoe

Thanks for the compliment, mark!
I've been following this discussion on the periphery, but haven't chimed in because I've been neutral on the whole issue, but here are my thoughts:

1). I find it interesting that nobody complained about the gearing on the 987 or the 981 before the GT4 came out. I can only assume that it was because people assumed it was from the lack of power and not the gearing. Now that the power has been added and the car still doesn't feel quick, attention has focused on gearing.

2). For street driving, I would agree that the car would be more fun with shorter gears, but this is a track car for me and I only care about the performance. Marks comments are in line with what believe to be true in that the car would be no faster on track with shorter gearing. As another data point, there is an owner who ran with a shorter gearbox and ultimately went back to stock gearing because he was no faster and found the gearing to somewhat of a hindrance.

3). I would validate mark's comments on gearing based on the track. The gears are a touch too tall for laguna as there are some turns where it's never entirely clear which is the best gear to be in. Whereas at Sonoma/sears point, the gearing is pretty much perfect. I have to short shift for some turns there, so shorter gearing would hurt, imo. Here is my video at Sonoma where I'm short shifting for t5 and t8.


Mark, I'd like to know what your thoughts are on T5 at laguna. I struggle with whether I should be in 3rd or 2nd entering that corner. In this video I'm in 2nd. The overall lap is faster, but it's not because of t5. I made up the time in t4. It feels faster coming out in 2nd, but data shows no real differences. I wonder if better driving would show a difference, though.

Manifold

I generally haven't heard many complaints about the gearing for the track. The main issue seems to be the lack of pep on the road, attributable in large part to the gearing. And I don't buy the argument that there needs to be a substantial tradeoff between track vs road gearing, since just about every other manual Porsche is a counterexample to that argument.

If Porsche had spent the time and cost to optimize the gearing of the GT4, accounting for the engine and both track and road use, would the resulting gearing be pretty much what it is now? I seriously doubt it.

orthojoe

Maybe, but what did you think of the cayman R's gearing? It's pretty much the same. My shifting in the 987 spyder was no different than the GT4

Manifold

I drove the Cayman R on the road yesterday. The gearing felt 'right', and the car had plenty of pep. To me, that's what matters on the road, I don't care about 0-60 time, etc. I never had an issue with the R's gearing on the track either.

I agree that the gear selection on the track seems to be about the same for both cars, so there's something not right about the R's gearing working well on both track and road, yet the GT4 lacking pep on the road. I'm guessing it has something to do with the gearing of the GT4 not working as well with low to moderate revs on the road, as compared to moderate to high revs on the track, due to the torque curve of the engine. The R (and 991 GT3) don't feel like muscle cars, but they do feel nicely responsive in a linear way, whereas the GT4 seems to take a while to wake up (and by then, on the road, you're often already going too fast).

GTgears

Ok, I'll bite...

I'm not going to go to the Nth degree on this because I just don't have the time to mess around with it. But watching Joe's fast lap and comparing speeds in gear, it's very obvious that the 3 gear kit presented to Pete would actually be very good at LS. In fact, the whole reason I did that shorter 3 gear kit in the first place was for you Nor-Cal guys because Sears, LS and THill are so much slower than a lot of the tracks run out east and in the south. What follows are a couple key sections where gearing could make substantial gains in speed and acceleration.

1. Main straight. Top speed of 125mph. In stock 4th, you can run up to 137mph. That's leaving a ton on the table. At the end of the straight you are nowhere near peak HP. With the 1.24 4th gear you are running it right up to 125mph. In fact, with a fast driver that might be a touch short and we would want to run a 1.20 instead and give you that extra 2mph buffer so that you don't hit the rev limiter.

2. Between 4&5. The shorter 3rd with a 100mph top speed would have him making that shift to 4th sooner and more time accelerating in 4th, not to mention the greater accerlation of 3rd coming out of 4 since you are at higher rpms as you start the section.

3. Sam basic analysis for the Rahal straight. Come out of 6 with more acceleration and higher top speed before you brake for 7.

4. 9-10-11 would be the only one I would want to look a bit more closely at. With the top speed on the 1.55 3rd being 100mph, a fast driver might be pushing the rev limiter. A 1.526 may be more appropriate, but either one would give better faster acceleration through that whole section.

The GT4 Clubsports run 1:36s at LS. In 2013 we ran it in 1:34 in a 3.8 swapped 987.2 using my gears. That car actually had 1.526 3rd and 1.174 4th because that was the protoype set that I made. We weren't optimizing for a single track because neither had the time nor the convenience to do it on the fly while fighting for the title. When I used to do this for Grand-Am GT cars we would regear the car for each track each weekend.

Bottomline, these gears are not optimized for the car. 3rd gear is garbage. I can improve someone's lap time on any track in the country with regearing this car. That's a fact.

orthojoe

Thanks for the analysis, Matt.
The only thing I would question is the amount of time that was gained. Randy Pobst did 1:37.4 at LS in a stock GT4. I would imagine that a clubsport should more more one second faster. I would have guessed 3. Also, doesn't the clubsport have shorter gearing with the PDK?

Alan C.

Joe, Thanks for the videos. I see your point on Laguna vs. Sonoma. In a perfect world you'd have a gear set for every track. If I built my box for Mid-Ohio I'd have to put a splint on my left arm for the back straight at VIR. It's all user dependent. I believe that has been Pete's position all along. Pick the compromise that best suits your needs. We are fortunate to have vendors capable of accommodating those desires.

GTgears

Yes Joe, you caught my subtle point... The Clubsport PDK gearing, as Bill showed with his thrust force graphs, is also going to be faster at LS.

If a second doesn't matter to you, maybe gearing isn't in your budget. I want to remind people that I'm not in the business of helping build hot rods. I make race car parts. We look for tenths. I can easily get you guys seconds using the same tools and parts I sell to my race clients, but that's not in everyone's hot rod budget. It's also pretty off topic to Pete's thread since I've always asserted 2nd is pretty damn good on a racecar and a big part of why I have not invested in the mainshaft project to date.

orthojoe

One second on track is a substantial gain

sharkster

Pretty sure Matt wrote 1:34 which = 4 seconds faster

orthojoe

4 seconds faster than what? You can't compare different cars and different drivers. Gearing alone cannot give you 4 seconds. The stock gearing isn't THAT bad