How to make a GT3 equal?
10-15-2007, 04:28 PM
#16
(back on topic from the chest beating and bench racing)
I think the GT3 is a track-prepped vehicle that still can be driven on a daily basis. It has SOME of its compromises shaved to the side of track use, and others are left alone.
When you purchase a GT3 today, you can get deviated stitching, GPS, AC, basically everything you can on a regular Porsche. But its supposedly lighter, it has a MUCH more serious engine and drivetrain, the suspension is much more robust and indeed quite adjustable.
Thats what I am shooting for, but I thought it was going to be to pozer to put GT3 on the 928, so I was going to do a simpe "RS" tag at the back.
I think the GT3 is a track-prepped vehicle that still can be driven on a daily basis. It has SOME of its compromises shaved to the side of track use, and others are left alone.
When you purchase a GT3 today, you can get deviated stitching, GPS, AC, basically everything you can on a regular Porsche. But its supposedly lighter, it has a MUCH more serious engine and drivetrain, the suspension is much more robust and indeed quite adjustable.
Thats what I am shooting for, but I thought it was going to be to pozer to put GT3 on the 928, so I was going to do a simpe "RS" tag at the back.
10-15-2007, 05:56 PM
#17
Rennlist Member
the only reason the 928 is such a great track car (well, several reasons) is that it can shed all of the luxury weight and be fitted with huge tires. the car has enough HP to race with some of the best cars ever made up until 2001.
once you compare apples to apples, say stock for stock, the 928 slides further down the list than most any car, mainly because of its weight. and skinny tires.
Again, that is good and bad. Good in that you can get a 928 pretty cheap and make it into a track car to beat or keep up with any street GT3, and fairly close to the stock vipers. But, its really not a fair comparison.
So, to answer what would it take to compete with the GT3? Well, the GT3 is almost the GT3cup car with a little more weight and almost the same HP. 390ish. if you could buy all of the heavy interior parts in Carbon fiber, replace all components like starters, exhuast, etc with lightweight versions, and were able to kick the hp to equal the HP to weight ratio of the GT3, you would still be a little behind the GT3's performance. the only real way to do this, would be to take a car like mark anderson's, Joe Fan's, and rebuild it custom to be a street car.
mk
once you compare apples to apples, say stock for stock, the 928 slides further down the list than most any car, mainly because of its weight. and skinny tires.
Again, that is good and bad. Good in that you can get a 928 pretty cheap and make it into a track car to beat or keep up with any street GT3, and fairly close to the stock vipers. But, its really not a fair comparison.
So, to answer what would it take to compete with the GT3? Well, the GT3 is almost the GT3cup car with a little more weight and almost the same HP. 390ish. if you could buy all of the heavy interior parts in Carbon fiber, replace all components like starters, exhuast, etc with lightweight versions, and were able to kick the hp to equal the HP to weight ratio of the GT3, you would still be a little behind the GT3's performance. the only real way to do this, would be to take a car like mark anderson's, Joe Fan's, and rebuild it custom to be a street car.
mk
(back on topic from the chest beating and bench racing)
I think the GT3 is a track-prepped vehicle that still can be driven on a daily basis. It has SOME of its compromises shaved to the side of track use, and others are left alone.
When you purchase a GT3 today, you can get deviated stitching, GPS, AC, basically everything you can on a regular Porsche. But its supposedly lighter, it has a MUCH more serious engine and drivetrain, the suspension is much more robust and indeed quite adjustable.
Thats what I am shooting for, but I thought it was going to be to pozer to put GT3 on the 928, so I was going to do a simpe "RS" tag at the back.
I think the GT3 is a track-prepped vehicle that still can be driven on a daily basis. It has SOME of its compromises shaved to the side of track use, and others are left alone.
When you purchase a GT3 today, you can get deviated stitching, GPS, AC, basically everything you can on a regular Porsche. But its supposedly lighter, it has a MUCH more serious engine and drivetrain, the suspension is much more robust and indeed quite adjustable.
Thats what I am shooting for, but I thought it was going to be to pozer to put GT3 on the 928, so I was going to do a simpe "RS" tag at the back.
10-15-2007, 06:07 PM
#18
Rennlist Member
The Pro's that did the test with the GT3 porsche are top porsche drivers in ALMS. I forget who did the test, but Ill see if i can dig up the drivers names.
mk
[QUOTE=SwayBar;
What do these guys normally drive?[/QUOTE]
mk
[QUOTE=SwayBar;
What do these guys normally drive?[/QUOTE]
10-15-2007, 06:15 PM
#19
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About the rear brake bias, I used (as did Mark Anderson at the PCA Sebring races now that I think about it) a 33 bar unit in the 1986.5 track car and found the brake balance with the stock S4 brakes just about perfect. Mark A. did not say anything negative about the brakes, except that I should not have changed both the pads and rotors just before the race. As he did more laps the brakes wore in and did very well. Mark A. can correct me on this point if needed.
However I'm not trying to defend any position about the rear brake bias. Brake bias adjustment to me is a fine handling adjustment after a few track sessions with the newly built car to find out what needs to be tweaked.
If there is anyone out there who wants to commission such a car, I have a space open in my garage and could be easily convinced to undertake such a mission...
However I'm not trying to defend any position about the rear brake bias. Brake bias adjustment to me is a fine handling adjustment after a few track sessions with the newly built car to find out what needs to be tweaked.
If there is anyone out there who wants to commission such a car, I have a space open in my garage and could be easily convinced to undertake such a mission...
10-15-2007, 07:18 PM
#21
https://rennlist.com/forums/showthre...ghlight=tt+gt3
I think with a 5 spd supercharged 928, Devek Konis, Hyperco Springs and Devek Sway bar you will be pretty darn close to keep up with a GT3 or even beat him. I don't know how hard they were pushing the TT and GT3 but my car had no problem keeping up with them and it was by no means a walk in the park. I was gaining CONSIDERABLY on them on straighways and out of corners.
I think with a 5 spd supercharged 928, Devek Konis, Hyperco Springs and Devek Sway bar you will be pretty darn close to keep up with a GT3 or even beat him. I don't know how hard they were pushing the TT and GT3 but my car had no problem keeping up with them and it was by no means a walk in the park. I was gaining CONSIDERABLY on them on straighways and out of corners.
10-15-2007, 07:34 PM
#22
Rennlist Member
http://www.motortrend.com/features/1...onclusion.html
so, in the end, you have to ask yourself, if your car can run a 1:39.5 or better on DOTs at laguna, you are on parity with this car.
However, i do disagree with their unfair tire selection. the GT3 was able to run michelin sport pilots, while the Vet Z06 with a lap time of 1:40.xx had to run goodyear F1 supercar tires. (dont know what these are, but im sure they are not as good as the michelins)
mk
so, in the end, you have to ask yourself, if your car can run a 1:39.5 or better on DOTs at laguna, you are on parity with this car.
However, i do disagree with their unfair tire selection. the GT3 was able to run michelin sport pilots, while the Vet Z06 with a lap time of 1:40.xx had to run goodyear F1 supercar tires. (dont know what these are, but im sure they are not as good as the michelins)
mk
10-15-2007, 07:40 PM
#23
Rennlist Member
its very hard to compare street performance to actual performance. just too many variables, mainly driver.
I always like to tell this story about testing to see if my tires would rub before my race at sears point. i ran up and down the mountain road of hyway 9 in saratoga. good mix of high speed ,and tight turns, with big braking areas. everything went well. no rubbing. guess what, on lap 2 of the race, the tire rubbed so bad that it pushed it off the rim!! G loading on the street just cant be simulated on the street. I still try and bed my brakes on the street. It just isnt the same as one lap at laguna.
back to the point of all this. its not just about HP or HP to weight as you can get most any car do this. its about the handling and braking. (the other 2/3s of the equation) So, back to the question, what does it take to make a 928 equal to a GT3 street? make a car like mine, or do something pretty extrodinary with a street 928 as far as power and overall weight and tire sizes.
mk
I always like to tell this story about testing to see if my tires would rub before my race at sears point. i ran up and down the mountain road of hyway 9 in saratoga. good mix of high speed ,and tight turns, with big braking areas. everything went well. no rubbing. guess what, on lap 2 of the race, the tire rubbed so bad that it pushed it off the rim!! G loading on the street just cant be simulated on the street. I still try and bed my brakes on the street. It just isnt the same as one lap at laguna.
back to the point of all this. its not just about HP or HP to weight as you can get most any car do this. its about the handling and braking. (the other 2/3s of the equation) So, back to the question, what does it take to make a 928 equal to a GT3 street? make a car like mine, or do something pretty extrodinary with a street 928 as far as power and overall weight and tire sizes.
mk
https://rennlist.com/forums/showthre...ghlight=tt+gt3
I think with a 5 spd supercharged 928, Devek Konis, Hyperco Springs and Devek Sway bar you will be pretty darn close to keep up with a GT3 or even beat him. I don't know how hard they were pushing the TT and GT3 but my car had no problem keeping up with them and it was by no means a walk in the park. I was gaining CONSIDERABLY on them on straighways and out of corners.
I think with a 5 spd supercharged 928, Devek Konis, Hyperco Springs and Devek Sway bar you will be pretty darn close to keep up with a GT3 or even beat him. I don't know how hard they were pushing the TT and GT3 but my car had no problem keeping up with them and it was by no means a walk in the park. I was gaining CONSIDERABLY on them on straighways and out of corners.
10-15-2007, 07:40 PM
#24
Race Director
http://www.motortrend.com/features/1...onclusion.html
so, in the end, you have to ask yourself, if your car can run a 1:39.5 or better on DOTs at laguna, you are on parity with this car.
However, i do disagree with their unfair tire selection. the GT3 was able to run michelin sport pilots, while the Vet Z06 with a lap time of 1:40.xx had to run goodyear F1 supercar tires. (dont know what these are, but im sure they are not as good as the michelins)
mk
so, in the end, you have to ask yourself, if your car can run a 1:39.5 or better on DOTs at laguna, you are on parity with this car.
However, i do disagree with their unfair tire selection. the GT3 was able to run michelin sport pilots, while the Vet Z06 with a lap time of 1:40.xx had to run goodyear F1 supercar tires. (dont know what these are, but im sure they are not as good as the michelins)
mk
Don't forget the GT3 already comes with Pilot Sport Cups...... the Z06 with its crappy run flats......I'm sure the Z06 could easily make up that 1.4 seconds with DOT R compounds.......I would guess a well driven R compound Z06 is probably a 1:38.?? car at laguna..just like the 20 year old 928 :>)
10-15-2007, 07:50 PM
#25
Rennlist Member
i just saw that!! what a CROCK!!!!! and angelelli couldnt figure out why there was oversteer with the vet???? 220tread wear vs a real DOT R tire like the sport cups!!! (tread wear of 80)
I dont think they are as bad as the toyo T1S that anderson and I used in my first speed World challenge race, but 1.5 seconds im sure would be expected, if not 3!
funny you wonder about a well driven vet. put it this way, one of the top vipers (scotty B White ) who use to be one of the top vet drivers ran his viper T1 car at laguna to a 1:38.xx. thats probaby where the vet would be. worst case, it would be a great race, one that I would love to participate in ! (either driving the vet, GT3 or my old 21year old dog 928!)
motortrend magazine, what a joke!!!
mk
I dont think they are as bad as the toyo T1S that anderson and I used in my first speed World challenge race, but 1.5 seconds im sure would be expected, if not 3!
funny you wonder about a well driven vet. put it this way, one of the top vipers (scotty B White ) who use to be one of the top vet drivers ran his viper T1 car at laguna to a 1:38.xx. thats probaby where the vet would be. worst case, it would be a great race, one that I would love to participate in ! (either driving the vet, GT3 or my old 21year old dog 928!)
motortrend magazine, what a joke!!!
mk
mk
Don't forget the GT3 already comes with Pilot Sport Cups...... the Z06 with its crappy run flats......I'm sure the Z06 could easily make up that 1.4 seconds with DOT R compounds.......I would guess a well driven R compound Z06 is probably a 1:38.?? car at laguna..just like the 20 year old 928 :>)
Don't forget the GT3 already comes with Pilot Sport Cups...... the Z06 with its crappy run flats......I'm sure the Z06 could easily make up that 1.4 seconds with DOT R compounds.......I would guess a well driven R compound Z06 is probably a 1:38.?? car at laguna..just like the 20 year old 928 :>)
10-15-2007, 09:06 PM
#26
Addict
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I like Constantine's recipe.
To be even more specific about it, the basic specs of a 997GT3 are:
hp: 384 rwhp
Curb weight: 3,075 lbs
Tires: 235/35 ZR 19 front, 305/30 ZR 19 rear
So if a 928S4 is your base, gut it to 3100 lb, mod the engine to 400 rwhp, put some custom wheels w/ appropriately wide tires, get a suspension pkg (springs, shocks & anti-roll bars) and hire Walter Rohrl to tune it. No problem.
GT3 also has some nice goodies like LSD, dry sump, aero mods, massive 6-piston ceramic brakes, Variocam, 6 spd, oil cooler, trans cooler, etc. Actually it kind of seems like a bargain for all the cool stuff you get . . .
To be even more specific about it, the basic specs of a 997GT3 are:
hp: 384 rwhp
Curb weight: 3,075 lbs
Tires: 235/35 ZR 19 front, 305/30 ZR 19 rear
So if a 928S4 is your base, gut it to 3100 lb, mod the engine to 400 rwhp, put some custom wheels w/ appropriately wide tires, get a suspension pkg (springs, shocks & anti-roll bars) and hire Walter Rohrl to tune it. No problem.
GT3 also has some nice goodies like LSD, dry sump, aero mods, massive 6-piston ceramic brakes, Variocam, 6 spd, oil cooler, trans cooler, etc. Actually it kind of seems like a bargain for all the cool stuff you get . . .
10-15-2007, 09:45 PM
#27
Race Director
don't forget some moton 4 way adjustables + the ability to change the internal pressure...so its like 5 way adjustables......those + some monster swaybars and huge tires on a lightweight 928 would be bad ***.....but it would take a while to get it tuned correctly with all those variables... a 928 with 315 front and 345 rear tires.....with over 500whp and 2850lbs with driver.....that would be silly fast.....oh wait I just described Andersons car!! :>)
10-15-2007, 10:06 PM
#28
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Have to agree with Dennis K., the street GT3 is really a bargain for what you get, and you can pick them up used nowadays.
Then again the street C6 Z06 is even a better bargain...But we're talking Porsche here, right?
And the GT3 Cup Car is a bargain in the race world really. A race team can buy a GT3 Cup, go racing in the pro ranks and have a good chance of finishing really well. Hire Mr. Pobst or some other hot shoe and you could potentially win. But then again nothing is ever a sure thing in racing.
Okay back on the subject. I conservatively calculate building a street 928 that can hang with a street GT3 would cost about $40-$50K including the 928S4.
Then again the street C6 Z06 is even a better bargain...But we're talking Porsche here, right?
And the GT3 Cup Car is a bargain in the race world really. A race team can buy a GT3 Cup, go racing in the pro ranks and have a good chance of finishing really well. Hire Mr. Pobst or some other hot shoe and you could potentially win. But then again nothing is ever a sure thing in racing.
Okay back on the subject. I conservatively calculate building a street 928 that can hang with a street GT3 would cost about $40-$50K including the 928S4.
10-16-2007, 12:15 PM
#29
Rennlist Member
Have to agree with Dennis K., the street GT3 is really a bargain for what you get, and you can pick them up used nowadays.
Then again the street C6 Z06 is even a better bargain...But we're talking Porsche here, right?
And the GT3 Cup Car is a bargain in the race world really. A race team can buy a GT3 Cup, go racing in the pro ranks and have a good chance of finishing really well. Hire Mr. Pobst or some other hot shoe and you could potentially win. But then again nothing is ever a sure thing in racing.
Okay back on the subject. I conservatively calculate building a street 928 that can hang with a street GT3 would cost about $40-$50K including the 928S4.
Then again the street C6 Z06 is even a better bargain...But we're talking Porsche here, right?
And the GT3 Cup Car is a bargain in the race world really. A race team can buy a GT3 Cup, go racing in the pro ranks and have a good chance of finishing really well. Hire Mr. Pobst or some other hot shoe and you could potentially win. But then again nothing is ever a sure thing in racing.
Okay back on the subject. I conservatively calculate building a street 928 that can hang with a street GT3 would cost about $40-$50K including the 928S4.
New 5.4GTS engine with GT cams, 928 Intl Headers, X-Over, 2.5” custom exhaust and Dry Sump
New GTS gearbox
2-way LEDA adjustable suspension
Big Blacks with SS Braded Hoses
Cobra Bucket Seats
FIA Approved Cadge
6-point TRS harnesses
18” OZ Racing Wheels
Pirelli Rosso Corsa Track Tyres 285/30/18 and 225/40/18
Fully Plumbed in Lifeline 2000 Fire Extinguisher
Removed Sound deadening
Removed interior
Total cost £20,000 excluding my labour, but including the 1990 GT, which is the base car. I am left with a GT engine with 25,000 since a total rebuilt, a GT gearbox and a set of S4 front brakes, which were rebuilt with the engine. Theroretically I can recoup around £5000 from the costs if I was to sell the GT parts... But they are my precious
10-16-2007, 12:45 PM
#30
Drifting
alex, i think your GT gearbox might make a good blender as its done a nice job smoothing out the diff you forgot to mention the 968 intake valves and headwork in your engine build spec, i do wonder what the relative gain is from the 968 valves versus the GT cams. save the S4 brakes for another 928 project...
the 911s are such a different car with all the weight in the back and they drive differently to a 928. ive only been round the ring once in a GT3 but it was interesting to see the way power could be applied earlier in the corners. i wouldnt say they need to slow down much before turning in either although there were a few times when it seemed the driver was 'slower in and faster out'.
by comparison the 928 is really quite benign in its balance and i think more forgiving to a novice driver, so i think to make it the equal of a GT3 you would have to compromise its handling first...
you forgot to mention the 968 intake valves and headwork in your engine build spec, i do wonder what the relative gain is from the 968 valves versus the GT cams. save the S4 brakes for another 928 project...the 911s are such a different car with all the weight in the back and they drive differently to a 928. ive only been round the ring once in a GT3 but it was interesting to see the way power could be applied earlier in the corners. i wouldnt say they need to slow down much before turning in either although there were a few times when it seemed the driver was 'slower in and faster out'.
by comparison the 928 is really quite benign in its balance and i think more forgiving to a novice driver, so i think to make it the equal of a GT3 you would have to compromise its handling first...