997 GTS - Topgear Exhausts

[Ovb1]

I’ve got a full system on my GTS. I had to buy the 200 cell cats from Gert in Belgium. They actually modify the existing manifolds to add high quality sports cell. http://www.carnewal.com/

I then added the rest of the system from Top Gear. It sounds superb but I have wondered about a ECU tune to maximise the performance?

Seems to be different opinions on whether this is a good idea or not.

 

[veetwin]

Yes, the car went into GAD this morning with TG Manifolds, Sharkwerks X-Pipe, PSE and BMC Air Filters all fitted.

Sadly I don't have a standard car baseline Dyno Print to work from, for comparison.

Anthony at GAD did comment that the power was close to Stock, and that the Standard ECU calibration doesn't do well at picking up the exhaust modifications in isolation, so he wasn't surprised. A Custom Map is required to bring everything together.

I can totally understand that, that makes sense to me. Though if you read Sharkwerks website they maintain their improvements don't require a remap to realise!

Honestly, mapping an NA car I was less focused on the BHP increase and have been more focused on the Torque figures. I wanted to achieve a higher torque figure lower down in the Rev-Range.

Coming out of slow corners, with PDK in 2nd gear the engine gets bogged down and you have no option to slip the clutch. Shifting down to 1st gear, all hell breaks loose.

Ive only had the drive home to compare, but definitely feels more urgent now

I can believe those power figures, its the torque that seems unbelievable to me.

For example, the 997.2 GT3 / GT3 RS produces 430 Nm as standard, and even the GT3 RS 4.0 "only" produces 460Nm. Your printout shows 461Nm before, and 493Nm after!

Charlie at Surrey Rolling Road (An independent dyno that doesn't map cars) suggested that 997.1 typically dyno at 330bhp unless rebuilt, 350 ish if rebuilt and 997.2 around 355-360 ish on his rollers. I suspect that mods that reduce pumping loss' will produce a benefit on the dyno but that to maximise it you probably need to adjust variable cam timing as well as the fuelling and ignition timing. The ECU probably has some scope to apply mild tweaks to fuelling and ignition timing to self-learn but often this only applies at low/mid load areas of the map and the wide-open throttle section of the map is just a look-up table without O2 feedback or much scope to advance timing. I've not remapped a 997 so can't be sure what the OEM ECU can and can't do.

Tried to book the car into Surrey Rolling Road. I've been emailing Charlie and it transpires that any PDK car requires a 'Linked Dyno' to avoid the ECU seeing differences in front to rear wheel speeds and going into limp mode, or reducing power. Basically you need a dyno that runs the front wheels at the same time/speed as the rear (like they did at GAD tuning). Newer PDK cars from I believe 991/981 models onwards have a Dyno Mode that can be initiated by PIWIS to avoid this issue.

Sadly Surrey RR dont have a Linked Dyno, so its a no-go to validate the output on my car. Sorry chaps.

Took the car out yesterday for a breakfast run and butt dyno can assure you that it is now pulling much harder than before, especially out of slow corners. Regardless of any printouts, Im much happier with the car now.

 

[veetwin]

For anyone with a 997 2wd with PDK* wanting to Dyno their car before/after mods, please read this -

https://www.planet-9.com/threads/pdk-dyno.143673/

A linked 4wd Dyno will be required, as I just learned...

* does not apply to Manual Transmissions, apparently

Every day is a school day

 

[flatstick]

Is it worth me rolling reading the car stock and then going back to the same place after? I'm based in Leeds so won't be GAD.

Look forward to this, has TG sorted out there manifold issues then?
There is BHP UK Dyno at Burnley and he used to have a 997
Dean

https://bhp-uk.net/our-ecu-remapping-gets-an-upgrade-with-the-latest-in-dyno-technology

What are the issues you speak of? I'm having to have the manifolds manipulated to fit by Tony Banks.

Ok, i have not heard back from TG yet, will be nearly a year at this rate.

 

[drmark]

Is it worth me rolling reading the car stock and then going back to the same place after? I'm based in Leeds so won't be GAD.

Look forward to this, has TG sorted out there manifold issues then?
There is BHP UK Dyno at Burnley and he used to have a 997
Dean

https://bhp-uk.net/our-ecu-remapping-gets-an-upgrade-with-the-latest-in-dyno-technology

What are the issues you speak of? I'm having to have the manifolds manipulated to fit by Tony Banks.

Ok, i have not heard back from TG yet, will be nearly a year at this rate.

If you are still interested I would ring / email them.

 

[Mezgerite]

No 997 needs a linked Dyno.

2wd 4wd PDK Tiptronic or Manual, i Dyno them all regularly. Please contact Unicorn Motor Developments.

 

[flatstick]

Is it worth me rolling reading the car stock and then going back to the same place after? I'm based in Leeds so won't be GAD.

Look forward to this, has TG sorted out there manifold issues then?
There is BHP UK Dyno at Burnley and he used to have a 997
Dean

https://bhp-uk.net/our-ecu-remapping-gets-an-upgrade-with-the-latest-in-dyno-technology

What are the issues you speak of? I'm having to have the manifolds manipulated to fit by Tony Banks.

Ok, i have not heard back from TG yet, will be nearly a year at this rate.

If you are still interested I would ring / email them.

I nave called and messaged loads of times, had the money refunded even offered my car to help solve their problems

 

[drmark]

Weird. And annoying.

 

[IMI A]

do a 100-200kph run that's what matters not dyno's

+1

 

[flatstick]

Weird. And annoying.

Its getting that way, good job i don't need them,just like spending on the car :floor: i might give Steve one more call tomorrow

 

[nuts]

Just booked in with Tony Banks to have the manifolds fitted with an x pipe. So won’t be able to report back until 7th November.

In other news got myself some BMC filters…

 

[flatstick]

Just booked in with Tony Banks to have the manifolds fitted with an x pipe. So won’t be able to report back until 7th November.

In other news got myself some BMC filters…

looks like the mods i want to do to my 4s, look forward to the results

Dean

 

[veetwin]

Your printout shows 461Nm before ! now 493NM !

yes this is not right, is this a DMS dyno lol

Best thing to do is run a 100-200kph time before and after I do this with all my cars to see real time gains.

My 997 GTS is 10.5 seconds with a manual I would expect a PDK to be 0.5 seconds faster.

My 991.2 manual GT3 which was a weapon and too fast which has 460NM torque.
And runs 8.2 100-200 kph.

A PDK now with 415bhp and >490NM would be in the 9's even high 8's 100-200 and I don't think it would do that on a stock engine with bolt ons.

Thing is does it matter if you have a before and after the figures are pointless if done at the same place, as long as you can see the gains that's great.

but a 100-200kph run would be great to see time wise or a run at Surry RR to see what you really have.

all my manual Porkers plus my test track starts uphill sadly for 30 yards but it's repeatable so on a straight I would expect slighty faster times.
1: 997 GTS 10.6 seconds 402 BHP /420NM
2: 718 Spyder 8.98 414bhp/ 420NM (was shocked how fast this car is really)
3: 991.2 GT3 8.2 493bhp/460NM

Just came back from three runs (private road) 100kph - 200kph

Run 1 - 10.22
Run 2 - 9.53
Run 3 - 9.73

All timed with Sport Chrono

 

[PorscheGT]

Not bad a little faster than my 997 GTS, but not as fast as my 718 Spyder.

 

[veetwin]

Just had the first MOT Test with the Top Gear Sports Cats/Manifolds fitted.

Went for a drive prior to testing to ensure the Cats were warmed up.

Test was a PASS, emissions were close to borderline when I asked (tester didnt provide readings)