911 vs Boxster - 3.4 . . . .

[khushy]

so - how do Porsche get 350BHP out of the same engine - both 3436cc???

Discuss :-)

khushy

[MadMark911]

Could be different cams (and hence cam timing), a less restrictive exhaust, different ECU program and maybe a larger inlet manifold?

[nickfrog]

And different mapping?

[khushy]

like an x51???

[Bennachie]

You develop a 3.4 with a cooking output and put it into say, a 987.2 knowing that the motor has tuning potential way beyond the initial outputs and very early on decide to use that engine (and its economies of scale) in all of your upcoming new sports models with varying outputs achieved by altering fuel maps, ignition maps, changing the throttle bodies, cam profiles/timing/lift, changing exhaust manifolds/system and possibly changing the heads.
VW/Audi have been doing it for years with their engines, particularly the diesels. Two litres but several spec. outputs. Admittedly it is easier with a turbo motor but the principles are similar, develop a 'base unit' knowing that it can be developed from there. The original 9A1 engine was probably designed to produce to produce, say, 400hp and was initially detuned for its initial installation. It is then fairly simple to produce sequentially more powerful versions of it for 987S, 987R, 981, and 991/991S etc.

[khushy]

so how much would it cost to put a "cooking" kit together for a Boxster 3.4 DFi and what would be the ingredients . . .

cams
ECU remap
Exhaust
Air Box
Plenum ??

khushy

[Ian_UK1]

khushy said:

so how much would it cost to put a "cooking" kit together for a Boxster 3.4 DFi and what would be the ingredients . . .

cams
ECU remap
Exhaust
Air Box
Plenum ??

khushy

Essentially, you'd need to look into what parts were different in the Boxster version of the engine compared to the more powerful 911 variants and modify accordingly. But... This mightn't be possible if the difference in output is caused simply by the engine's installation in the car. It could be, for example, that the positionining of the engine in the Boxster simply means the intakes and exhaust are more restrictive (but I doubt it).

I'm sure I read somewhere (on an American forum) that someone had put a 997 3.8 DFI lump in a Gen-2 Boxster S to very good effect. Doing a complete transplant might eventually cost less than stripping the 3.4 and changing however many components are required. You also know with a transplant that there's a standard Porsche ECU map that will work perfectly with the engine.

There's also the traditional n/a tuning methods available to you (intake, cams, manifolds, exhaust etc.) or - again from America and FAR more effective - a forced induction kit. I think TPC do something appropriate and you'll see an extra 80/90 BHP not just an extra 10/20 for your outlay. The F.I. kits can also be removed completely, returning the car to standard, before resale/trade-in.

For the money that you might spend on big engine mods, I think an F.I kit will give massively bigger increases for a similar outlay.

[khushy]

if someone was after 10% only it cannot be that hard/expensive surely?

khushy

[uktrailmonster]

khushy said:

if someone was after 10% only it cannot be that hard/expensive surely?

As the old motorsport saying goes "speed costs money, so how fast do you want to go?"

You'd probably get 10% on an exhaust kit and aggressive re-map. The next 10% would probably start getting much more expensive.

[khushy]

320 bhp (boxster) to 350 bhp (911) = ???

[HokumPokum]

perhaps there is also the element of whether the throttle is fully open on the 987. I think that on C63s , the main difference was this vs the E63 with the same engine and a slightly different exhaust. I am not saying this is the only difference but could be a significant one.

[SonnyM]

khushy said:

320 bhp (boxster) to 350 bhp (911) = ???

After all the mods you'll realise it costs the same or less to buy a 350hp 911, ffs.

[mollytherocker]

SonnyM said:

khushy said:

320 bhp (boxster) to 350 bhp (911) = ???

After all the mods you'll realise it costs the same or less to buy a 350hp 911, ffs.

Its nearly always cheaper to buy the 'right car' in the first place. Money spent developing a Boxster is dead money in my view.

Sell up and buy the car you want.

MTR

[BubblesNW]

Have a look at this ...

http://www.tpcracing.com/products/TPC-Racing-9872-...

Pretty impressive as it's a PDK car. No performance numbers but the dyno readings are impressive.



I think Parr would be willing to install.

Edited by BubblesNW on Friday 22 June 14:26

[rob.kellock]

I'm guessing he wants a Spyder that's a bit more powerful. Can't otherwise get one of those!

[mrdemon]

khushy said:

so how much would it cost to put a "cooking" kit together for a Boxster 3.4 DFi and what would be the ingredients . . .

cams
ECU remap
Exhaust
Air Box
Plenum ??

khushy

it's all tried and tested

race exhaust deleting all 4 cats
997 GT3 throttle body
remap to tie it all in and stop the cel light
and a vflow intake.

should be 345 to 350BHp and not that expensive.

get the weight out and a Spyder would be 278BHp/ton :-)

[OlberJ]

khushy said:

so how much would it cost to put a "cooking" kit together for a Boxster 3.4 DFi and what would be the ingredients . . .

cams
ECU remap
Exhaust
Air Box
Plenum ??

khushy

The 1st 5 will help but not sure a khushy will actually improve performance.

Maybe make a bit more noise but real world gains won't be much.

[MadMark911]

OlberJ said:

khushy said:

so how much would it cost to put a "cooking" kit together for a Boxster 3.4 DFi and what would be the ingredients . . .

cams
ECU remap
Exhaust
Air Box
Plenum ??

khushy

The 1st 5 will help but not sure a khushy will actually improve performance.

Maybe make a bit more noise but real world gains won't be much.

A Khushy permanantly installed in the car? The Amercians could use him to replace the white noise generators that they use for torturing innocent terrorists ....

[Ekona]

mrdemon said:

it's all tried and tested

race exhaust deleting all 4 cats
997 GT3 throttle body
remap to tie it all in and stop the cel light
and a vflow intake.

should be 345 to 350BHp and not that expensive.

get the weight out and a Spyder would be 278BHp/ton :-)

GT3 throttle body on a DFI engine?

[mrdemon]

Ekona said:

GT3 throttle body on a DFI engine?

Yes it's a larger 82mm unit.