Planet-9 Porsche Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
85 Posts
Discussion Starter #1
Just watched the Ignition video and top of first is 46 and top of second is 82 mph. I am very into autocross and these gears do not look promising, especially after reading about low power low in the rpm range. Any delivered GT4 drivers thoughts on this? As an example I take a big pax hit with my 07 GT3RS because I have a Cup Car ring and pinion, lower gearing. Not really wanting to take a hit by changing the gearing in the GT4, but it looks like it will be a dog at autocross.
 

·
Registered
Joined
·
540 Posts
I have done a lot of Auto X and will be doing it with my GT4 . Seems to me that in most Auto X events constant speed is the key. Sure some cars make up for this in HP. There is a reason MX5's and smaller cars always do well. I would worry more about brake modulation and throttle control than gearing. Fastest driver around here (and most of the south) drives a old 1970's 911 and dominates everybody. Not a lot of HP there !!!
 

·
Registered
Joined
·
140 Posts
Are they going to put the Zone 1 results online? ;)

If you downsize to 19" and the right size tire, it'll help. I'm not sure if you are looking at street tires or A7 but tire options aren't great in 19, 20".
 

·
Registered
Joined
·
85 Posts
Discussion Starter #4
Are they going to put the Zone 1 results online? ;)

If you downsize to 19" and the right size tire, it'll help. I'm not sure if you are looking at street tires or A7 but tire options aren't great in 19, 20".
Don't start me going on Zone 1. Split heats suck! And splitting IP in one run group and M in the other was a real bad choice. Rick N and I had a battle for FTD last year (I took it) and I was looking forward to another battle this year. I never got a dry run being in the first run group on Sunday, but did manage to pull one out of my butt to take I2.
I suppose I could change the ring and pinion but want to keep it stock other than tires, and squat for tire choices in 20s.
I do a lot of autocross, 35+ days a season. Also set a lot of courses, including day one for the Zone for the last 5 years.
 

·
Registered
Joined
·
534 Posts
Gearing for ALL 981s is too high for autocross. The one trick you have up your sleeve though is to go with a smaller wheel and tire package - which is an easy way to give your car lower gearing. That said, an aftermarket setup might bump you into a different class.

On a semi-related note, I found PDK equipped cars have a big advantage on the autocross course. Having a manual, I found that I left my car in 2nd gear the whole time and just focused on steering and braking. The top guys in my class were running PDK, shifted frequently, and were subsequently quicker than myself.
 

·
Registered
Joined
·
540 Posts
Gearing for ALL 981s is too high for autocross. The one trick you have up your sleeve though is to go with a smaller wheel and tire package - which is an easy way to give your car lower gearing. That said, an aftermarket setup might bump you into a different class.

On a semi-related note, I found PDK equipped cars have a big advantage on the autocross course. Having a manual, I found that I left my car in 2nd gear the whole time and just focused on steering and braking. The top guys in my class were running PDK, shifted frequently, and were subsequently quicker than myself.
I am no expert by any means! It seems to me that the biggest advantage of having PDK is at the starting line with Launch Control. My 981 CS had PDK and I ways always picking up time from Launching. I never did see a point in a lot of shifting until you got to the end of some courses and had to make the 90 degree turn back. Matter of fact I left it in Sports Plus most of the time and achieved my best times doing so.

The GT4 with its sports button on ( auto rev match ) will make down shifts in odd places on a course work to your advantage. I am sure there are some that will claim they can Rev Match or Heel Toe anywhere on an autoX course...I am not that person.


The way the GT4 pulls in 2nd gear above 3,800 I see no problem here. Get her up to speed and keep her in 2nd and down shift only when you feel you are going to go below 3,800. With the balance and breaking capability of the GT4 you should be able to maintain a really smooth and constant speed.
 

·
Registered
Joined
·
534 Posts
It all depends on how fast the course is. If you're fast enough that 2nd gear is optimal the entire way, then PDK doesn't offer much benefit on the course. However If the course is a fast 1st gear and slow 2nd gear course, you may find yourself shifting more than you'd like. For a MT car, this is going to cost you a lot of time over a PDK.
 

·
Registered
Joined
·
85 Posts
Discussion Starter #8
It all depends on how fast the course is. If you're fast enough that 2nd gear is optimal the entire way, then PDK doesn't offer much benefit on the course. However If the course is a fast 1st gear and slow 2nd gear course, you may find yourself shifting more than you'd like. For a MT car, this is going to cost you a lot of time over a PDK.
As the course designer I try very hard to make it so most cars can have the line they want. Power or momentum. Does not always work out that way, but I try. For damn sure the gearing will work well for Loring next year. I set up a 1.5 type course there. About 90 max mph. Only one car went John Deere this year, tried to correct too many times. It is at the tip of Maine and a 3 day event in early August.
 

·
Registered
Joined
·
540 Posts
So on tonight's break in drive I specifically drove thanking about this thread. In 2nd gear in the GT4 your RPM's almost match your MPH. Doing 42 MPH = 4,200 RPM's ECT all the way up to 7,800. The GT4 pulls VERY hard at 4,200 RPM's vs any other 981 including the GTS. I have driven all models so I can say this with confidence. The gearing may be long but there is plenty of power to be had! The 3.8 makes all the difference in the world. I see the GT4 being a better car for auto X than the GT3 including the RS versions IMO. Better balance better breaking due to a lighter car and its smaller so its easier to squeeze through without hitting any cones. Those J-LO hips always seem to catch an extra cone or 2;)
 

·
Registered
Joined
·
85 Posts
Discussion Starter #10
So on tonight's break in drive I specifically drove thanking about this thread. In 2nd gear in the GT4 your RPM's almost match your MPH. Doing 42 MPH = 4,200 RPM's ECT all the way up to 7,800. The GT4 pulls VERY hard at 4,200 RPM's vs any other 981 including the GTS. I have driven all models so I can say this with confidence. The gearing may be long but there is plenty of power to be had! The 3.8 makes all the difference in the world. I see the GT4 being a better car for auto X than the GT3 including the RS versions IMO. Better balance better breaking due to a lighter car and its smaller so its easier to squeeze through without hitting any cones. Those J-LO hips always seem to catch an extra cone or 2;)
As long as I can get equal tires I will be able to compare the GT4 to my RS. Mind you, my RS has aftermarket sways, -3 at the corners, cup car ring and pinion, massive lockup LSD, 18" wheels, and alignment. I get even wear on the 255s in front and the 315s in back.
Really hoping I can fit my 18s on the car. I have 3 sets for A7s and one set with Ho Ho rains.
 

·
Registered
Joined
·
448 Posts
Scruffy, I don't think you can compare any stock car with your RS. It is set up optimally for our autocross venue.
Dave in NE-SVT has come into his own this season and is now regularly FTD in a 981S on Hoosiers, running on tighter courses that keep the engine in the lower RPM range.
I think Ochocorona's observations give some insight into how the GT4 will perform at our venue. We have the room to get our cars up to speed so if what he says holds true, we'll be in the meat of the powerband in 2nd gear for most courses.
We may have to wait a while for tire sizes but Sport Cup 2s will work until something better comes along.
 

·
Registered
Joined
·
85 Posts
Discussion Starter #12
Scruffy, I don't think you can compare any stock car with your RS. It is set up optimally for our autocross venue.
Dave in NE-SVT has come into his own this season and is now regularly FTD in a 981S on Hoosiers, running on tighter courses that keep the engine in the lower RPM range.
I think Ochocorona's observations give some insight into how the GT4 will perform at our venue. We have the room to get our cars up to speed so if what he says holds true, we'll be in the meat of the powerband in 2nd gear for most courses.
We may have to wait a while for tire sizes but Sport Cup 2s will work until something better comes along.
So maybe it will take some time for me to learn mid engine. My steering inputs in Kermit tend to be very violent in order to kick the *** around.
 

·
Registered
Joined
·
183 Posts
No question the GT4 is highly compromised by its tall second on most courses. This is by design- 2nd is geared to Viper speeds, or almost as high as a 930 4 speed. If you're running the 'ring this might be ok, anywhere else it has the convenient side effect of keeping the GT4 slower than a Carrera S.

The resulting hole is too big for the 3.8 to cover. Rolling on from 35-40 mph there is no good gear- you're off boil in 2nd well below the torque plateau but you're too high for 1st. No question it's going to slow the GT4 down off hairpins, etc. The active first will help, easy to grab if the corner is slow enough, but what the car really needs is a ring and pinion and a 67 mph 2nd gear (like a 7.2 GT3 RS). Not just for the autocross.

I'm heading to my first event Sunday and intend to beat up on a few GT3s, but it will be in spite of the tall gearing, not because of it.
 

·
Premium Member
Joined
·
324 Posts
I'm heading to my first event Sunday and intend to beat up on a few GT3s, but it will be in spite of the tall gearing, not because of it.
And the verdict is???
 

·
Registered
Joined
·
85 Posts
Discussion Starter #18
I read it, good report. Yes you were a bit late in the slalom. Hoping mine gets here early enough in October to put 2-3 events on it before stuffing it in the garage before winter. Our courses here are a quite a bit longer than that one.
 

·
Registered
Joined
·
85 Posts
Discussion Starter #19
I have a feeling you'll adjust within a day!
I almost adjusted within a day. Thanks for letting me drive your "momentum" Cayman R. An all around good experience. One thing I learned is that some parts of the course where my RS would fly through really bogged down your CR. I had my foot down from the vendetta box exit to the end of the taxi way but it was like watching paint dry compared to my RS.
 

·
Registered
Joined
·
16 Posts
Subscribed! Will be autocrossing when I get mine in June. I will run in SS for SCCA, so locally I can run the stock tires,
or 200tw alternatives. Does anyone have feedback on how the stock tires do in autocross, vs the recent crop of sticky
extreme '200tw' tires? I also considered lowering the gearing by going to 19" wheels with other tires...
 
1 - 20 of 20 Posts
Top