991 TT Aerodynamic Data
#46
There was a small period in time last year where I was on the hunt to be as light as a GT2 RS without spending thousands and thousands of dollars and losing creature comforts. The main difference really is our AWD system. If we were also RWD the weight difference would be negligible to 90% of drivers.
#47
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
I went through the same thinking process, but there is a bit more to it, and the GT2RS is simply a fabulous car. My 991TT is currently about 3 seconds faster than the fastest GT2RS on Cup2R, on a 5.4 mile circuit, but it took a lot of money, research and testing to get there, and a very powerful stage 4 by Sam with methanol and waterspray. If I was to do it again I would definitely go the GT2RS way and modify it further, but I already have a turbocharged 997 GT3 RSR which is my true race car so it would be a bit silly.
The following users liked this post:
pepinozaur (04-24-2020)
#48
[QUOTE=Jean;16575765]I went through the same thinking process, but there is a bit more to it, and the GT2RS is simply a fabulous car. My 991TT is currently about 3 seconds faster than the fastest GT2RS on Cup2R, on a 5.4 mile circuit, but it took a lot of money, research and testing to get there, and a very powerful stage 4 by Sam with methanol and waterspray. If I was to do it again I would definitely go the GT2RS way and modify it further, but I already have a turbocharged 997 GT3 RSR which is my true race car so it would be a bit silly.
[/QUOTE
]
Excellent info Jean.
If you were to replace your 991TT with a GT2RS, would you add Meth to the GT2RS or just run the external spray system ?
[/QUOTE
]
Excellent info Jean.
If you were to replace your 991TT with a GT2RS, would you add Meth to the GT2RS or just run the external spray system ?
#49
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
To be honest I wouldn't know at this stage, I would have to test first. Knowing how fast I go down the slippery slope, car would have another 70-80HP at a minimum, new suspension, smaller wheels and aerodynamics. I have been amazed by methanol, after over a decade pushing back on it, I feel the 991 knock sensing and electronics make it a very safe bet nowadays. I just hate having that meth tank in the front on a street car and all those hoses and wires..
#50
Rennlist Member
#51
Racer
9A1 111 335 80 (i think these are the brackets. But not 100%. Need to check)
9A1 111 336 80
991 504 257 81 (tthis is the diffuser. You can also get it from Suncoast)
BTW i have all of this brand new never used. Went on a different direction. Check you oil pan to see if it has holes to bolt it on. If it doesn't you will need to tap the areas where the bolts go. Pretty easily done by a good shop
9A1 111 336 80
991 504 257 81 (tthis is the diffuser. You can also get it from Suncoast)
BTW i have all of this brand new never used. Went on a different direction. Check you oil pan to see if it has holes to bolt it on. If it doesn't you will need to tap the areas where the bolts go. Pretty easily done by a good shop
#52
Intermediate
9A1 111 335 80 (i think these are the brackets. But not 100%. Need to check)
9A1 111 336 80
991 504 257 81 (tthis is the diffuser. You can also get it from Suncoast)
BTW i have all of this brand new never used. Went on a different direction. Check you oil pan to see if it has holes to bolt it on. If it doesn't you will need to tap the areas where the bolts go. Pretty easily done by a good shop
9A1 111 336 80
991 504 257 81 (tthis is the diffuser. You can also get it from Suncoast)
BTW i have all of this brand new never used. Went on a different direction. Check you oil pan to see if it has holes to bolt it on. If it doesn't you will need to tap the areas where the bolts go. Pretty easily done by a good shop
#54
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
#55
@Jean , did you just fit the OEM GT2RS Decklid to the 991TT, and then no modifications required?
Since you seem to have upgraded Wings to a larger one, would you be interested in selling your GT2RS Rear Wing?
Also, if you remove the Active Aero Rear Spoiler, does it cause the Front Inflatable Rubber Spoiler to cease working?
Since you seem to have upgraded Wings to a larger one, would you be interested in selling your GT2RS Rear Wing?
Also, if you remove the Active Aero Rear Spoiler, does it cause the Front Inflatable Rubber Spoiler to cease working?
#56
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
@Jean , did you just fit the OEM GT2RS Decklid to the 991TT, and then no modifications required?
Since you seem to have upgraded Wings to a larger one, would you be interested in selling your GT2RS Rear Wing?
Also, if you remove the Active Aero Rear Spoiler, does it cause the Front Inflatable Rubber Spoiler to cease working?
Since you seem to have upgraded Wings to a larger one, would you be interested in selling your GT2RS Rear Wing?
Also, if you remove the Active Aero Rear Spoiler, does it cause the Front Inflatable Rubber Spoiler to cease working?
I only used them for one race and then took them out because I am planning to stop racing the 991TT, the car is now back with stock aero, the parts are stored at home, soon to be joined by Manthey competition KW, a bunch of Tarrett parts and a full stage 4 Bydesign system.
I had the front inflatable spoiler removed and disabled as well when I fitted the front GT2RS bumper. The custom made aero parts in the pictures above will be fitted on the GT2RS.
#57
The decklid and wing were decent replicas (so not worth international shipping costs etc) and the fitment was not simple at all, not because of the quality, but because of the disposition of the air intakes on the GT2 decklid being on the sides while the turbo is a central intake on the decklid.. Also the stock filter box doesn't fit and the lock was another issue.
I only used them for one race and then took them out because I am planning to stop racing the 991TT, the car is now back with stock aero, the parts are stored at home, soon to be joined by Manthey competition KW, a bunch of Tarrett parts and a full stage 4 Bydesign system.
I had the front inflatable spoiler removed and disabled as well when I fitted the front GT2RS bumper. The custom made aero parts in the pictures above will be fitted on the GT2RS.
I only used them for one race and then took them out because I am planning to stop racing the 991TT, the car is now back with stock aero, the parts are stored at home, soon to be joined by Manthey competition KW, a bunch of Tarrett parts and a full stage 4 Bydesign system.
I had the front inflatable spoiler removed and disabled as well when I fitted the front GT2RS bumper. The custom made aero parts in the pictures above will be fitted on the GT2RS.
Seems like it's a bit of a pain to get it all done and sorted out then?
#58
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
It is not the easiest conversion if you want to do it yourself, but an experienced shop who has done it before can get it sorted quickly.
#59
Racer
- Decklid, decklid plate, actuator, airbox, intake / inlet to air box and struts. Off course uprights wing etc.
- 1 3RS: Shares the same position on the fans therefore you can retain the top cover. You will need to make a hole on the center of the decklid to make sure the inlet works. Additionally you will need to shave the fins down on the airbox to make sure the box fits under the decklid plate.
- 2RS: Best scenario here is that you buy the 2RS inlets and air box. Fans are positions difference so you will need new engine cover as well. Second option is to modify this and treat them similarly to how you would do the .1 3RS. Defeats the purpose of the air inlets on the decklid as the fans are position to extract air not bring air in. You will loose efficiency this way. Third option i have seen if to remove the air box all together and put two single filters in the engine bay. This would be the most economical not sure how efficient and you would probably be sucking some of the hot air from the engine bay as well.
Under either scenario OEM parts are really expensive. With that said i have found that most after market parts are really heavy and or need a lot of work to make them fit well, ultimately ending costing almost the same. If you can find some used OEM parts or a good supplier of dry carbon Fiber parts probably the best way to go
- GT3 Cup: What i like about this scenario is the ability to use OEM parts at somewhat more reasonable prices. Also you can definitely find good quality aftermarket race parts at even better prices. For this scenario you will need to custom make the airbox. Non of the scenarios above (other than using two open single filters) will work.
Once you do this you need to be mindful that the front spoiler wont work. You will need to change that as well. If you are heading this route you will need to change A LOT of parts. Front bumper, center radiator, center radiator duct work, side radiator duct work, front splitter, front side splitter, left and right fenders, fender liners, front wheels (if you want to fill in the fenders), etc. Happy to send you a full list. Each model is a bit different as well.
Hope this helps
#60
Racer
The guys at Orbit Racing will coordinating the sale of these plus a bunch of other parts I have. Unfortunately I sold some parts to another forum member and got burned pretty bad. These are brand new, still in the box. They also have tons of parts from my initial build btw. Talk to Shawn. let me know if you need his contact info