[Boodzz]

has anyone considered getting an aftermarket exhaust system ? if so which (if there is any)

 

[widowmaker911]

has anyone considered getting an aftermarket exhaust system ? if so which (if there is any)

If you opted for the sport exhaust (INCONELS) there is NO NEED for after market. That is about as good as it gets and McLaren's (I don't know who built is, if it was made in house (Porsche uses Akrapovic )) is just beautifully made.
If you didn't get it I would see if dealer can swap to SPORT

 

[MP4ME]

This was one of the questions i had for McLaren and i was told that from the cats back there is no advantage to and aftermarket exhaust, they seemed to think they have it optimized.
On Ferrari's and Porsche's putting on higher flowing cats has a huge improvement in power and also weight saving. I would be interested to here if someone is working on a cat replacement option.

 

[andy c]

This was one of the questions i had for McLaren and i was told that from the cats back there is no advantage to and aftermarket exhaust, they seemed to think they have it optimized.
On Ferrari's and Porsche's putting on higher flowing cats has a huge improvement in power and also weight saving. I would be interested to here if someone is working on a cat replacement option.

Probably,but many of the tuning houses will just want to make their own just for sales rather than optimizing something that is just so.I shouldnt think its a big deal putting in a higher flowing cat for extra performance,but they will want to re-design the whole thing to say its unique and charge a higher price for something that isnt.As widowmaker says how can you improve on inconel with a tiny baffle box thats almost a straight through exhaust system,at this level its a backward step.
As a foot note Mclaren spent so much time on the exhaust system,they mangaged to homologate the steel version at the last minute in thinner lighter steel than originally specced making it only a kilo heavier than the inconel one,in my mind no other manufacturer would have gone to those lengths other than a race team that never stops development untill the last minute,its what they do.
I will just catch my breath and get off my soap box now,rant over,imop

 

[GT-TT]

4 cats. At -2 cats you ll get performance. But only if the rest of the tuning package is in place (ECU etc).

 

[andy c]

4 cats. At -2 cats you ll get performance. But only if the rest of the tuning package is in place (ECU etc).

Agree on that GT,if you can find the room,why not just put 100 cell cats in place of the standard ones,probably not as good but you wouldnt have to find the space??Always easier on a 911 they can just hang down a bit lower?

 

[widowmaker911]

4 cats. At -2 cats you ll get performance. But only if the rest of the tuning package is in place (ECU etc).

The 12C has 4cats? I only see two and they look 200cell types?......I wonder what McLaren did to get extra 75hp (rumored) on the HS. I would guess turbo/intercoolers upgraded and INCONEL manifolds with retune ECU ;0)

 

[MP4ME]

of course doing ECU tuning with changing the exhaust/cats is the optimum way to go, but my experience with both forced induction Porsche's and NA Ferrari's is that simply reducing the"plug" that is the cat/exhaust system allows the motor to suck and blow much more freely which means more BHP! . I have not seen a production header on the 12C, but the ones i have seen on the "rolling chassis" look very basic and not tuned, which is indicative of the fact that Mac got the power from the turbo/intake instead of trying to super tune the exhaust.
Either way i think that there is way more power to e tapped from this engine, but how does it effect the traction control and all relevant systems !!

 

[andy c]

of course doing ECU tuning with changing the exhaust/cats is the optimum way to go, but my experience with both forced induction Porsche's and NA Ferrari's is that simply reducing the"plug" that is the cat/exhaust system allows the motor to suck and blow much more freely which means more BHP! . I have not seen a production header on the 12C, but the ones i have seen on the "rolling chassis" look very basic and not tuned, which is indicative of the fact that Mac got the power from the turbo/intake instead of trying to super tune the exhaust.
Either way i think that there is way more power to e tapped from this engine, but how does it effect the traction control and all relevant systems !!

You make a good point,would it be usable power without altering the current systems?Only at the top end as the TC is so good im sure anything under 125 mph would slow the car unless you increased the contact patch and re-tuned the TC,also they had initial problems with the cooling,so for the HS to get more power they had to increase the cooling,so an after market bolt on exhaust /turbo/ ecu could be a major backward step for engine life IMO,might be good for drag racing!!
Just look how good it was against the r8gt,similar power against fwd and it was dead meat

 

[GT-TT]

- 2 cats, ecu will (should make) 60hp on this car. Headers is another area of improvement as there were compromises made for the acoustic character of the engine and thus this cast design is not optimal for power.
Andy, am not sure about the space as I don't own a 12c (yet) and i can't quite remember the design. But speaking to engineers a while ago i heard it was certainly possible to just delete 2 cats (if i remember correctly) and then improving on the other 2. However if I am not mistaken the ecu is Bosch which means it is "torque" based which means that exhaust flow alone will not make substantial increases. Probably more midrange & response than peak power.
Beyond the 660-670hp area you would need better flowing turbos (yes they exist by same brand) and also after that, improvement in cylinder head flow. The big question about this drivetrain for me however is the rods and gearbox allowance for torque. 600nm is on the low side for a 3.8tt V8 and although mclaren has hinted on flat torque/power curve, i think that there is more behind that decision.

 

[falb]

Simply unleashing the boost bleed in the mid range should up the torque quite a bit but will create a very un-linear power curve that will certainly make the car harder to control on a road course.

I believe the headers are a single cast unit that is integrated with the turbine housing. A little machining may be okay but you are looking at a complete unit.

As for the exhaust, perhaps a couple pre-cat boost actuated dump tubes to relieve any back pressure!?!?! This way you retain the factory exhaust, cats, emissions, and get to increase flow when needed.

 

[andy c]

I agree with you all about the potential of the engine,its just the amount of work they have put into the electronics and how it would affect the drivabilty of the car and ultimatly the outright performance,as they say power without control !!
It will certainly be an interesting few years as everyone in the tuning market will have their say,lets sit back and see who comes up with something that works better and is just as robust,and i might consider it when my warrenty runs out.We know through experience how far you can take it on a flat 6,and the internals of this engine must be impressive if its been de-tuned from the original 10,500 rpm unit.
Still its the first car ive owned that i didnt want to mess with

 

[falb]

The power delivery on this car is sooo linear that it doesnt feel explosive in a strait line, but after taking this car on the track it really highlights how much power this car has across the rpm range. No power for me thanks!!

 

[andy c]

The power delivery on this car is sooo linear that it doesnt feel explosive in a strait line, but after taking this car on the track it really highlights how much power this car has across the rpm range. No power for me thanks!!

Voice of reason,after watching your vid,what more does it need??

 

[GT-TT]

in my track time i thought that more low/mid torque (and less lag) would be desirable in this car, especially since the smart suspension gives a lot of corner exit traction.
I think around 700-720hp with around 750-800NM would be perfect and still very driveable. I think we are 6 months to 1 year before someone offers this power level.
Andy the rods are apparently nth special so lets forget about 900-1000nm of torque here. Also this gearbox is an unknown entity but i heard that 700nm+ is probably ok for it.

 

[Senna]

I would not mess with it ( the 12C). I spent a couple of days in a Friends
GT2 RS last week , and as impressive as it was, the car felt archaic, in the power delivery, and the traction control intervention, and for want of a better description just "to fast for a stick shift"
Build quality is to usual German standards, but the ride quality was of Flintstones proportions ..12C ! don't mess with near perfection
I think if we start messing with the 12C we will end up with a GT2RS !!!

 

[andy c]

in my track time i thought that more low/mid torque (and less lag) would be desirable in this car, especially since the smart suspension gives a lot of corner exit traction.
I think around 700-720hp with around 750-800NM would be perfect and still very driveable. I think we are 6 months to 1 year before someone offers this power level.
Andy the rods are apparently nth special so lets forget about 900-1000nm of torque here. Also this gearbox is an unknown entity but i heard that 700nm+ is probably ok for it.

Interesting about the rods!If they do use this engine in the F1 looks like they have left plenty of potential in it,i assumed the rods would be better than you say given the internal speed of the original engine, i know the torgue is the more important factor,but given the quality of the engine it seems to be a small expense.As for the gearbox i agree thats a completely different matter

 

[BIG_DJE]

mine will be going in for ECU software and remove the 2nd set of cats and myabe x pipe

#1 is louder sound
#2 more power

 

[falb]

I'm confused. What is the deal with the rods? Hard to imagine them not being up for serious additional boost.

 

[Senna]

mine will be going in for ECU software and remove the 2nd set of cats and myabe x pipe

#1 is louder sound
#2 more power

I don't mean to be rude or disrespectful in anyway, but please explain to me the X-pipe ?
Have you actually looked at the configuration of the 12C's exhaust ? From the cat back it is basically a straight pipe with either a link pipe or small muffler joining the tail section above the gearbox. I cannot believe there is any power to be found there ! or noise for that matter. But if you still interested in an X pipe, i have some land in Florida and a bridge from London for sale