Well price cat back manifolds - Top Gear? - Page 1 - 911/Carrera GT - PistonHeads UK

well, they look nicely made and well priced, could be great ?! https://www.topgear.co.uk/porsche-997-2-carrera-ca...

Adrian-9iafn said: well, they look nicely made and well priced, could be great ?! https://www.topgear.co.uk/porsche-997-2-carrera-ca... I have the 997.1 ones. Very nice. Be warned though, if running with their 200 cell cats they do change the exhaust note. It is very loud above 4500 under load, so much so I never use the sport button on the PSE on ours. Some may like it. Some not. No droning.

Cool, thanks, any problems with sensors at all ? My car is a 997.2 3.6 with a X-pipe rear box delete and no sports boxes

expect to stick a 90 degree extender in for the o2 sensors as it may throw a code when pressing on

I'm pretty sure that these will justify (or need) a live remap as there are decent gains (circa 20hp) to be had from their fitment.

Slippydiff said: I'm pretty sure that these will justify (or need) a live remap as there are decent gains (circa 20hp) to be had from their fitment. No chance. I ran TG on 2 cars, both mapped, almost zero to no gain from the exhaust itself.

Great quality. When open it's virtually a straight through 3" pipe. Is a significant restriction when closed though, I wouldn't do WOT with it closed, but great for cruising when closed. Exactly how you want it.

ImbackYo said: No chance. I ran TG on 2 cars, both mapped, almost zero to no gain from the exhaust itself. DFi or M96/M97 engined cars ? If DFi it’s a reflection on the design of the TG manifolds and cats they use, because the DFi engines usually respond well to well designed long tube manifolds and less restrictive cats.

Slippydiff said: DFi or M96/M97 engined cars ? If DFi it’s a reflection on the design of the TG manifolds and cats they use, because the DFi engines usually respond well to well designed long tube manifolds and less restrictive cats. 997 GT3 and 996 Turbo. And later on a v10 R8. They're a good bunch and produce a great product, but you are not getting 20bhp from the exhaust and map on a N/A engine. Would love to see the results though if the OP wants to post them up.

ImbackYo said: 997 GT3 and 996 Turbo. And later on a v10 R8. They're a good bunch and produce a great product, but you are not getting 20bhp from the exhaust and map on a N/A engine. Would love to see the results though if the OP wants to post them up. Correct, you won’t get a 20hp gain from a 997 GT3 with an exhaust and remap, they were well optimised from the factory. My 996 GT2 with a Ruf exhaust and a map did 540hp (same engine as the non-X50 996 Turbo, but bigger turbos, bigger intercoolers) Mk 1 996 GT3 with a Manthey K400 conversion (long tube M&M manifolds , 200 cell HJS cats, bigger bore pipework, better flowing silencers, Cup air filter, MAF delete and remap) Increase of 40-45hp (the Cup filter and MAF delete were primarily to make the mapping more straightforward) MA1.01 responds really well to decent manifolds and cats (I’ll be brutally honest, the Top Gear stuff may be ok, I have no experience with their products) but there’s two German exhaust manufacturers whose products (manifolds and cats) will liberate 20hp from an otherwise stock 3.8 997.2 DFi engine with a remap. Edit to add video link. https://m.youtube.com/watch?v=sVFTypYmjqY This was the early days of Jens Ehresmann’s tuning the 3.8 DFi engines. The GT4 tuning package included a cool air induction package, but if you look in the description, he details the mods and the power gains. Decent manifolds and cars liberates 15hp, optimise them with a live remap and you can expect a total gain of 20-23hp. Edited by Slippydiff on Friday 12th April 20:54

Slippydiff said: I'm pretty sure that these will justify (or need) a live remap as there are decent gains (circa 20hp) to be had from their fitment. Not convinced. Took my car with to Wayne Schofield (who knows these cars well) with Topgear manifolds, 200 cell cats after Hartech 4.1 complete rebuild and only gained 30 bhp from the whole job (albeit masses more torque). And, to my surprise, the tailor made (expensive) remap added almost no extra to the standard factory one. Edited by anonymous-user on Friday 12th April 21:28

Discombobulate said: Not convinced. Took my car with to Wayne Schofield (who knows these cars well) with Topgear manifolds, 200 cell cats after Hartech 4.1 complete rebuild and only gained 30 bhp from the whole job (albeit masses more torque). And, to my surprise, the tailor made (expensive) remap added almost no extra to the standard factory one. Yours is a Gen 1 car featuring an M97 engine, not a DFi engine, the OP’s car is DFi. IF the TG stuff is any good, it’ll liberate 20+ hp on a DFi 3.8 engine with one of Wayne’s live remaps. If it’s not, it won’t. End of. But if if it’s not any good, why would you fit it in the first place ? If you recall, I asked (on this very forum) why the peak gains for your 4.1 conversion weren’t as great as a 3.9 conversion carried out on 3.6 996.2. No one was forthcoming with an answer, but it was obvious to me why, because both the M96.1 and 2 engines, and the M97 engines were extremely well developed by Porsche, and they left little or nothing on the table unless you were prepared to open your wallet to the tune of £8k and tick the X51 option box, and a quick look at the sheer breadth of modifications included in the X51 kits tells you what was required to extract 20-26hp from the M96 and M97 engines. Ergo the standard 3.8 M97 heads (which I think are identical to the 997.1 3.6 Carrera items) are incapable of flowing any more CFM, so you can increase the capacity all you like, and you’ll see minimal if any horsepower gains over those you saw with your 4.1 conversion. Torque yes, horsepower no. The only way to get further power gains to the M96/97 engines is bigger ports and valves, along with higher lift, longer duration cams, something I believe Baz and Grant are pursuing with their development partners currently. Now you’ll say well how come it takes a factory X51 kit costing many thousands of pounds to increase the horsepower of the 997.2 3.8 DFi from 385hp to 408hp ? Yet you’re suggesting an aftermarket exhaust and remap can produce the same gains for at least half the cost? Well the DFi engines respond far better to “bolt on” tuning and remapping than the M96/97 engines, and Porsche has to meet stringent noise restrictions and emissions tests. The aftermarket doesn’t (currently). If you don’t believe the gains I’m suggesting are possible, feel free to contact Jens Ehresmann in Germany, or BGB Motorsports or Deman Motorsport in the States, and ask them. There is a caveat though, and that is those gains will only be seen with properly developed manifolds and a remap written by someone who understands how the strategy for the resonance flaps in the inlet plenum needs to be optimised to ensure the improved breathing afforded by the more efficient manifolds and cats. Wayne S is a genius at this stuff, and he proved it with the 997 Cup engine we’d shoehorned into the back of my 996.1 GT3. The OP may want to ask TG about the scope of their development program on the MA1.01 engine, and also ask to see some dyno sheets to back up any performance claims they make.

Slippydiff said: Yours is a Gen 1 car featuring an M97 engine, not a DFi engine, the OP’s car is DFi. IF the TG stuff is any good, it’ll liberate 20+ hp on a DFi 3.8 engine with one of Wayne’s live remaps. If it’s not, it won’t. End of. But if if it’s not any good, why would you fit it in the first place ? If you recall, I asked (on this very forum) why the peak gains for your 4.1 conversion weren’t as great as a 3.9 conversion carried out on 3.6 996.2. No one was forthcoming with an answer, but it was obvious to me why, because both the M96.1 and 2 engines, and the M97 engines were extremely well developed by Porsche, and they left little or nothing on the table unless you were prepared to open your wallet to the tune of £8k and tick the X51 option box, and a quick look at the sheer breadth of modifications included in the X51 kits tells you what was required to extract 20-26hp from the M96 and M97 engines. Ergo the standard 3.8 M97 heads (which I think are identical to the 997.1 3.6 Carrera items) are incapable of flowing any more CFM, so you can increase the capacity all you like, and you’ll see minimal if any horsepower gains over those you saw with your 4.1 conversion. Torque yes, horsepower no. The only way to get further power gains to the M96/97 engines is bigger ports and valves, along with higher lift, longer duration cams, something I believe Baz and Grant are pursuing with their development partners currently. Now you’ll say well how come it takes a factory X51 kit costing many thousands of pounds to increase the horsepower of the 997.2 3.8 DFi from 385hp to 408hp ? Yet you’re suggesting an aftermarket exhaust and remap can produce the same gains for at least half the cost? Well the DFi engines respond far better to “bolt on” tuning and remapping than the M96/97 engines, and Porsche has to meet stringent noise restrictions and emissions tests. The aftermarket doesn’t (currently). If you don’t believe the gains I’m suggesting are possible, feel free to contact Jens Ehresmann in Germany, or BGB Motorsports or Deman Motorsport in the States, and ask them. There is a caveat though, and that is those gains will only be seen with properly developed manifolds and a remap written by someone who understands how the strategy for the resonance flaps in the inlet plenum needs to be optimised to ensure the improved breathing afforded by the more efficient manifolds and cats. Wayne S is a genius at this stuff, and he proved it with the 997 Cup engine we’d shoehorned into the back of my 996.1 GT3. The OP may want to ask TG about the scope of their development program on the MA1.01 engine, and also ask to see some dyno sheets to back up any performance claims they make. You misunderstand. I should have made my point clearer. I don't know which of the mods I did - a complete rebuild, oversize to 4.1, or the manifolds and cats - added which proportion of the power and torque to my car BUT, once all these were done, the remap on a rolling road added virtually nothing to the standard map. Hence my conclusion that a remap isn't essential if just fitting manifolds and cats. With the benefit of hindsight I needn't have bothered but wanted to check everything was optimised.

Discombobulate said: You misunderstand. I should have made my point clearer. I don't know which of the mods I did - a complete rebuild, oversize to 4.1, or the manifolds and cats - added which proportion of the power and torque to my car BUT, once all these were done, the remap on a rolling road added virtually nothing to the standard map. Hence my conclusion that a remap isn't essential if just fitting manifolds and cats. With the benefit of hindsight I needn't have bothered but wanted to check everything was optimised. Fair enough, though I’d suggest the TG stuff added no horsepower (or absolutely minimal gains for the reasons given above) and the stock ECU map would indeed have been able to re-adapt to the increase in capacity (something I believe Baz has alluded to in his posts on here and 911 UK, as has Jake Raby in his posts on Rennlist) IIRC, you were the first customer/guinea-pig for the 4.1 conversion. Grant offered me that first 4.1 build slot for my 996.2 C2 3.6 engine, but I was unwilling to be that guinea-pig. If Wayne was unable to find an additional horsepower from a remap, I’d suggest there was none to be had, due to the restrictions the heads/ports/valves present. I think it was also Jake Raby who suggested the 997.1 3.8S cylinder head ports were the same size as those of the 3.6, though I may have misconstrued what he said. No matter, the OP’s car is a DFi engined variant, and fitted with a decent (and reassuringly expensive) set of manifolds and cats, will see the gains I’ve alluded to, if properly mapped.

Slippydiff said: Fair enough, though I’d suggest the TG stuff added no horsepower (or absolutely minimal gains for the reasons given above) and the stock ECU map would indeed have been able to re-adapt to the increase in capacity (something I believe Baz has alluded to in his posts on here and 911 UK, as has Jake Raby in his posts on Rennlist) IIRC, you were the first customer/guinea-pig for the 4.1 conversion. Grant offered me that first 4.1 build slot for my 996.2 C2 3.6 engine, but I was unwilling to be that guinea-pig. If Wayne was unable to find an additional horsepower from a remap, I’d suggest there was none to be had, due to the restrictions the heads/ports/valves present. I think it was also Jake Raby who suggested the 997.1 3.8S cylinder head ports were the same size as those of the 3.6, though I may have misconstrued what he said. No matter, the OP’s car is a DFi engined variant, and fitted with a decent (and reassuringly expensive) set of manifolds and cats, will see the gains I’ve alluded to, if properly mapped. I wasn't the first Slippy, think they had done 5-10 before me, and far more 3.9s.

Discombobulate said: I wasn't the first Slippy, think they had done 5-10 before me, and far more 3.9s. Perhaps the first 996.2 3.6 to 4.1 conversion then ?