Increasing HP in 996TT

[AZ996TT]

Can someone explain this: B&B exhaust, and others claim to increase hp in 996TT by 35-45hp for anywhere from $500-5000, while still meeting emissions testing. Has anyone done this and dynoed their car to confirm these claims? If so, why opt for X50 for the same hp increase and pay what $18000, prior to its inclusion in the 996TT S, besides that it is a factory option? Am I missing something?

Thanks,

JB ;)

[Beecher]

Can someone explain this: B&B exhaust, and others claim to increase hp in 996TT by 35-45hp for anywhere from $500-5000, while still meeting emissions testing. Has anyone done this and dynoed their car to confirm these claims? If so, why opt for X50 for the same hp increase and pay what $18000, prior to its inclusion in the 996TT S, besides that it is a factory option? Am I missing something?

Thanks,

JB ;)

I just installed a Fabspeed medium sport exhaust which is supposed to give an extra 35 hp. I haven't put the car on a dyno, I wanted some exhaust note beyond the baby's sneeze stock sound. Yes, the X50 package seems very expensive for what you get. I plan to go with a GIAC computer flash with their flashloader so I can return to stock at service time. I figure that I'll have spent $3500 for the exhaust and $2250 for the flash so I will be way ahead of the $17,500 X50 package. I would have been happy to buy a used turbo with the X50, but the car I bought didn't come with it. Used car prices don't seem to support the idea of buying the X50 and getting the money back when you sell the car. X50 cars seems to sell for about the same money as regular ones in similar condition. Just my 2 cents...

[Kiko]

your statement is like saying: Why spend X amount of money on a Porsche for 420 Bhp if I can buy a 'Vette for a lot less?.

The difference between X50 and normal Turbo is not just software. Its about bigger turbos (k24's), bigger intercoolers (same as GT2's), steel syncros reinforced gearbox (some say its not..), Heavy duty clutch and a different exhaust (some say its not but the truth is the part number is different) and different software. This set up will provide a rock solid reliability and a much greater potential for future mods...

[ari1856]

Most exhausts give you about 40HP increase in the midrange due to quicker spool up of the turbos, The peak power increase is more like 15HP. These figures are for an otherwise stock (non X50 car).

I just had a Remus exhaust installed. I find it is the closest to stock (but deeper) under idle and light cruise conditions with an incredible throaty howl at full throttle. There is NO droning when you take your foot off the gas and on downshifts. This exhaust costs 2-3 K less than the competion, is full stainless and performs very well on my 560HP X50 car. It comes with 200 cell cats and will probably pass emmissions long after 100 cell cats are worn out.

Here are some quick clips: http://members.dslextreme.com/users/twintu...emus%20Exhaust/

There is a dyno test by someone on 6speed that backs the performace quoted above.

BTW I asked abot B&B and got an almost unanymous NO due to poor sound and quality control issues. I have no personal experience with the B&B.

Edited January 18, 2006 by Ari

[Ed NY]

your statement is like saying: Why spend X amount of money on a Porsche for 420 Bhp if I can buy a 'Vette for a lot less?.

The difference between X50 and normal Turbo is not just software. Its about bigger turbos (k24's), bigger intercoolers (same as GT2's), steel syncros reinforced gearbox (some say its not..), Heavy duty clutch and a different exhaust (some say its not but the truth is the part number is different) and different software. This set up will provide a rock solid reliability and a much greater potential for future mods...

What specifically are additional mods that can be added to the X50 package? Do the increases in HP also add torque?

Edited February 10, 2006 by Ed NY

[Kiko]

I said future mods which means that for instance a software upgrade for the X50 will provide a lot more power and torque when compared with the normal Turbo which is limited by the K16's to provide reliable boost over 1,1 bar.

Increasing Power always means torque as well in these cars, actually in term of percentage, if I'm not mistaken there's a bigger increase in torque than in Power although power is torque x rpm.

[CO996C4]

Hey ARI where'd ya get the Remus exhaust at? Have you done any emissions tests with it? I live in Denver area and they are pretty stringent. I don't think 100 cell cats would cut it. Have you looked into EVO K24 headers for the X50?

Jim

[ari1856]

I live in CA. I believe we have THE most stringent tests in the country. My car easily passed emission testing WITH all of my mods installed.

I'll try and answer everyone's questions.

I have an 02 X50 with 11K miles. It is rated at 560HP/TQ. YES, 110HP AND 110 ft/lb more torque. I run 1.2 BAR with spikes seldom to 1.3. Compare this to .8 bar with spiuke to .9 bar stock.

Here is a list of the mods:

1. GIAC 91 Octane software with a handheld controller that can return the settings to stock. I do not have the "RACE" program as I don't really care for the extra 20HP/TQ and only put in the best pump gas we have (91 octane). I have never used the stock mode. :)

2. Remus Exhaust. This is the euro spec exhaust with bigger piping. I find this to be the quietest in cruise and seriously bad *** when you punch it. It doesn't get rid of the car's natural tendency to resonate between 2500-3000 RPM, I don't think anythig does. That is just a fact of this car. There is some "popping" under deceleration which is a product of the emissions doing their job (burning un-burned fuel before it goes into the air). The Exhaust just lets you hear it. I LOVE the sound and the quietness all at once. This exhaust like most 996TT exhausts give you quicker spool resulting in about 40HP/40TQ midrange and 15Hp/15 TQ peak (on a stock car). The best part? The price! Thousands less than the competition.

3. Evo V-flow intake. Agian quicker spool, more mid range torque and 15 HP peak.

4. Stock wastegate actuators upgraded to 1 BAR springs. I believe the factory springs are rated at .6 BAR. The stock wastegates tend to be "forced open" or "flap open" against the stock springs actually hurting spool up. This mod give you a LOT quicker spool but the same total boost. Net effect = more midrange HP/TQ

5. Billet diverter valves. I thought this was a BS mod, until one of my stock plastic diverter actually blew into pieces. You really need this. Stock or not.

5. FVDspec PSS9 suspention. Once you go Pss9 you won't believbe how bad the stock suspention really is! The 996 was actually RAISED 1" by the factory to meet US bumper specs. The dual springs allow for about 1" of super soft travel before totally collapsing, then the almost twice as stiff springs take over. Smoother than stock ride, and almost twice as stiff when you take a corner hard. Really the best of both worlds. FVD gives you stiffer secondary springs than stock PSS9. Same ride, stiffer seconary springs.

The car has gone from scary to of sh**t! It is totally drivebale and a blast. Just be careful because it will do 90+ on city steets before you can say ticket. It can also be deceptively fast going from staights into a corner. You get used to it, but THANK you for Porsche those brakes.

Here are is list of my vendors. Thay have been fantastic to deal with:

1. GIAC X50 Programming: Lucent motors http://www.lucentmotor.com . Arling is awesome.

2. Remus Exhaust, Billet Diverter Valves and Wastegate Actuator MOD. http://www.thespeedgallery.com a seriously great set of guys that know Porsches!

3. FVD Spec Pss9s. http://www.fvdusa.com. Jay from FVD actually checked out a 9700 mile car I bought out of florida sight unseen and had shipped. The car was spotless!

I know I can get EVO headers and get 600Hp/TQ and might do that in the future. Honestly, being a car freak I never thought I would say this, this car is already too fast for the street. But knowing me, I'm sure I'll get headers (or ported stock headers) soon!

Edited February 11, 2006 by Ari

[CO996C4]

Thanks! Have been wondering what mods really are worth it! I am installing the Bailey DV30 diverters and Porsche X73 suspension soon on My X50. Been checking out the airbox, tuning, exhaust,header stuff too but wanted to be sure

Jim

[glug]

I have been offered a cheap upgrade for my standard tt.

A local garage say they have achieved 480bhp by giving a tt the GT2 map. They say they can overcome the potential problems with the differences in the cams.

The cost of this will simply be the time taken, 1 hour at the hourly rate so $75 for 60 bhp.

Can anyone see a danger in this method?

[ari1856]

Sounds like they are re-programming your ECU with aftermaket performace software which is fine. That should give you about 480 HP.

What he ARE NOT doing is putting in GT2 software. You have smaller turbos which flow differently, but baically the same engine.

[glug]

I'm not too sure of the tech but the garage said they bought from Porsche the capability to reinstall the maps for the cars that they service. This is presumably to remedy faults in customers cars. They said they have applied a GT2 map to a tt tip' and achieved 480 bhp.

This sounds like a great opportunity for a very cheap increase in power when most tuners in England want $1700+. Surely someone has done this before if it's so easy?

I'll post in a couple of weeks with an update when it's done.

[Kiko]

glug,

I seriously doubt it, do you mind if I post this on another forum? give it a try but PLEASE show us the dyno afterwards to check if the car is running lean, rich, kicking the timing back or whatever...

Loren please step in...

[glug]

Kiko,

Please feel free to ask other folks. I guess I should take her for a dyno run before the remap as a comparison.

Am I right in thinking that the engine could detonate if the car was set up too lean?

[Kiko]

If theres something wrong with the software the dyno will be all over the place...

[glug]

I need to find a specialist to run the dyno. I'm told that unless the front propshaft is disconnected before the power run the viscous clutch and front diff can be seriously damaged. It seems the only way to get a figure is to run it 2wd. Anyone heard these horror stories?

[aracerx]

I need to find a specialist to run the dyno. I'm told that unless the front propshaft is disconnected before the power run the viscous clutch and front diff can be seriously damaged. It seems the only way to get a figure is to run it 2wd. Anyone heard these horror stories?

ANYTIME, ANYONE doesn't know enough to disconnect the coupling shaft for a "pull" Methinks you would be better off NOT doing business there. We "repaired" a few TT's that have had this issue. MAN, it's terrible to see some of the shafts that come out of those poor machines. AND, the viscous coupling gets damaged at the same time.

I do have my doubt of substantive HP/TORQUE improvement through exhaust change. It's mostly a sound change that people equate to improvement in performance. M

[glug]

Which parts would be damaged, shafts in front diff?, viscous clutch?, other? How would the damage show?. Would it be obvious when driven?

[Zippy]

I have been offered a cheap upgrade for my standard tt.

A local garage say they have achieved 480bhp by giving a tt the GT2 map. They say they can overcome the potential problems with the differences in the cams.

The cost of this will simply be the time taken, 1 hour at the hourly rate so $75 for 60 bhp.

Can anyone see a danger in this method?

Running a GT2 file, designed for K24 turbos on a K16 car is stupid. Stay away from that garage. There are several options available to increase performance of a K16 car, but running a K24 file is not 1 onf them.

[alexcwt]

I need to find a specialist to run the dyno. I'm told that unless the front propshaft is disconnected before the power run the viscous clutch and front diff can be seriously damaged. It seems the only way to get a figure is to run it 2wd. Anyone heard these horror stories?

ANYTIME, ANYONE doesn't know enough to disconnect the coupling shaft for a "pull" Methinks you would be better off NOT doing business there. We "repaired" a few TT's that have had this issue. MAN, it's terrible to see some of the shafts that come out of those poor machines. AND, the viscous coupling gets damaged at the same time.

I do have my doubt of substantive HP/TORQUE improvement through exhaust change. It's mostly a sound change that people equate to improvement in performance. M

Are you saying that it should be disconected or not? Why would it incur any damage if it's disconnected and no power going to it? The viscous clutch is in the front axle housing.

[wross996TT]

Are you saying that it should be disconected or not? Why would it incur any damage if it's disconnected and no power going to it? The viscous clutch is in the front axle housing.

Disconnect it for most (if not all) dynos.