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58 minutes ago, crafty1 said:

Following this closely and some tangible gains from what you are saying here.

 

Fwiw and this is only what I am told that to really gain power you need to lose the cats or fit free flowing 200 Cel jobbies. It kind of make sense as not much point increasing air intake capacity if the car is strangled on the exhaust side. 

 

I asked Gert when I saw him and he said much the same. I've got my eye on a set of these www.topgear.co.uk/porsche-987-2-cayman-boxster-manifolds-and-cats

 

 

 

I'd like to get 200 cel cats, but the car will be too noisy for track work. I've decided to go with a DMS map, heading down tomorrow.....let's see what happens.

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I have a similar dilemma ref noise on track and catless / 200 cel headers. When I get them done (eventually) I may sell the Carnewal exhaust and get something switchable or alternatively invest in a set of these for tracks days.

 

http://www.actproducts.co.uk/product/si06-porsche-gt3-sliencers-pr/

 

Slighty off topic but relevant and a tip for noise tests. This weekend at Snetterton at the static noise test I turned off my A/C and depressed my clutch, the noise meter read 100db at 5,000 rpm, last time I was there and without doing the above my reading was 104.5 db.

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2 hours ago, Andrea Frasky said:

 

I think your map will be a waste of money if you first don't change the restrictive exhaust.  No point letting more air in if then can't escape as quick.... 

 

200 cells cats won't add any noise anyway. I have catless manifolds and PSE and yes it is loud when the valves are on but other than that it's farly quite. 

 

My 2 cents

 

Nope.  Plenty of gains to be had without touching the exhaust.

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12 hours ago, Andrea Frasky said:

 

I think your map will be a waste of money if you first don't change the restrictive exhaust.  No point letting more air in if then can't escape as quick.... 

 

200 cells cats won't add any noise anyway. I have catless manifolds and PSE and yes it is loud when the valves are on but other than that it's farly quite. 

 

My 2 cents

I know what you're getting at, the cats are a restrictive part of the system. But the my understanding is that the standard back-boxes were also a restriction (now remedied). Along with a with the inlet modification (IPD + TB + filter + de snork) I'd expect to see some reasonable gains, I'll upload the graphs later.

 

If I do get the headers replaced later down the line, then I'll get it remapped again then we''l know how restrictive they really are.

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10 hours ago, crafty1 said:

I have a similar dilemma ref noise on track and catless / 200 cel headers. When I get them done (eventually) I may sell the Carnewal exhaust and get something switchable or alternatively invest in a set of these for tracks days.

 

http://www.actproducts.co.uk/product/si06-porsche-gt3-sliencers-pr/

 

Slighty off topic but relevant and a tip for noise tests. This weekend at Snetterton at the static noise test I turned off my A/C and depressed my clutch, the noise meter read 100db at 5,000 rpm, last time I was there and without doing the above my reading was 104.5 db.

Great tip there Crafy! I'll give that a try.

 

My biggest problem is on track at Bedford at the final hairpin, I'm right at the top of third as I go past the mic and I'm about 0.5 DB under the limit. 

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13 hours ago, Craiglm68 said:

 

##In the interests of sharing and full disclosure, I've attached the 2 maps...1st is DMS's (they applied a mutiplier when printing it out so I never got to see the "At Wheel" numbers, but they suggested my engine was "very healthy" re its outputs before the map, no doubt in part due to the filter/Carnewal combo). The 3 maps on the next photo are for the 3 runs on Regal's Dynos and are "at wheel" numbers. I was sceptical of DMS's outputs initially (though the Backside Dyno definitely felt a difference), the later dyno run at Regal was for peace of mind (and came up with almost identical numbers)

IMG_2346 (1).jpg

IMG_2636 (1).jpg

Thanks for sharing these, I'll ask DMS what multiplier they are using and see if they'll print at the wheels and correct for the flywheel.

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The wheel/flywheel number shouldn't be a fixed multipler.  The losses between flywheel and wheels will increase with RPM.  You can't just say peak power is always 15% or 18% over wheel HP.

 

A good dyno can be configured to calculate flywheel/wheel losses rather accurately at each RPM interval.

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Posted (edited)
1 hour ago, Aaron said:

The wheel/flywheel number shouldn't be a fixed multipler.  The losses between flywheel and wheels will increase with RPM.  You can't just say peak power is always 15% or 18% over wheel HP.

 

A good dyno can be configured to calculate flywheel/wheel losses rather accurately at each RPM interval.

I see, that makes sense.

 

Just got back from DMS.....who wants to see the graph? 😎

Edited by Dougle_turbo
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22 hours ago, Andrea Frasky said:

 

I think your map will be a waste of money if you first don't change the restrictive exhaust.  No point letting more air in if then can't escape as quick.... 

 

200 cells cats won't add any noise anyway. I have catless manifolds and PSE and yes it is loud when the valves are on but other than that it's farly quite. 

 

My 2 cents

I'd have to disagree with you on how much extra noise having no cats will add. I know from personal experience on many different cars, and on the race cars I used to run that the difference is substantial. Thats also backed up by Gert Carnewal who specifically told me not to put in sports cats if I wanted to pass track noise limits, even though I was in his workshop at the time trying to pay him to do it.

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3 hours ago, Dougle_turbo said:

I see, that makes sense.

 

Just got back from DMS.....who wants to see the graph? 😎

Yep 

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Great result, that said it was pretty strong beforehand too.

 

Over 109bhp per litre with usable torque is impressive for any NA engine.

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Has anyone had an MOT with 200 cell headers and the carnewal GT exhaust? My car is close to the emissions on the new printouts you get, so I'm wondering whether I'd have issues with the headers on top of my exhaust.

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I might be wrong, but I'm not sure the back boxes effect emissions?

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I think Dougle is correct. most of the emissions are controlled by the primary cats. the secondary's are probably fitted as standard to allow Porsche to sell in countries with even stricter emission laws than us

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