911Time's Project 991 - Cargraphic Manifold Upgrade

Hi all,

Sorry, I've not posted for a while - maybe that's no bad thing - but here I am to bore you senseless again Healthwise, I'm still battling on with my cancer/chemo and using a variety of projects to keep me fully occupied. Porsche related Facebook stuff, various clubs and shows all keep me busy now but I thought some of you might be interested in the latest developments with the car.

For those that remember, I bought a lovely 991 C4S back in 2019 and carried out a number of (hopefully) tasteful mods, to make it into one of a kind - all whilst keeping it sufficiently OEM, to maintain the extended warranty:

Previous Projects
Re-trim in Black/Grey Pepita: http://www.911uk.com/viewtopic.php?t=141075&postdays=0&postorder=asc&start=0

Gauges Re-Printed in 901 Spec Green: http://www.911uk.com/viewtopic.php?p=1561015

Bespoke 'Exclusive' Mats: http://www.911uk.com/viewtopic.php?p=1564061

Bespoke Grille Badge & Carrier: http://www.911uk.com/viewtopic.php?p=1579365











Moving Forwards
That was all Phase I. Since then a few years have rolled by, I've re-filled the coffers, dropped the warranty (self insured) and am embarking on Phase II.

My car came fitted with PSE, which sounds amazing but after 4 years, I was starting to look for something more. Preferences for exhaust sound are very personal but for me, I wanted to retain the 991 sound but with a bump in volume - there was also the opportunity to improve gas flow over OEM.

After a lot of thought and research, I settled on changing the stock manifolds and cats, for less restrictive ones and looked at (in no particular order), Fabspeed, Soul, Cargraphic, Topgear, plus a few less well known bespoke manufacturers.

All were good, most very responsive to enquiries and technical questions but for me, Cargraphic ticked all the right boxes and they couldn't have been more helpful! So, it was that I ordered a pair of their long tube manifolds in stainless steel, with 200 cell (Cargraphic specific) HJS cats and Modena style exhaust tips.

I always prefer dealing direct and importing them from Germany, with an FX transfer, helped me to save some money for other things.







Mad I know (as they're hidden and discolour anyway) but I'm a bit obsessive and fancied having the manifolds mirror polished. Back in the good ole days, I'd have done it myself but I'm not really up to that sort of thing now. So my good friend and neighbour Peter, stepped up to the plate.

We cordoned off an area of my garage and used an angle grinder (guard removed) with a Norton blending disc (2SF) to give a satin finish, then a felt flap wheel, with fine metal polish and finally a cotton wheel, with Meguiars NXT.











The next job was getting the old manifolds off and the new ones on: Despite changing exhausts many times in the past, people told me no end of horror stories about corrosion & snapped bolts on 911s and after my "I've done this sort of thing before and in any case, it's just a bl**$y exhaust" comments wore thin, it became apparent my original idea, to undertake the work at my home (with Peter lending his strength) probably wasn't the best approach - particularly if it all went pear shaped and bolts needed to be drilled out of the heads!

Peter generously spent the next week under my car, wire brushing the bolts and dosing them in Plus Gas, whilst Mike at Sports and Classic Ltd kindly agreed to remove the old manifolds and fit the new ones. I should add that fitting customer supplied parts isn't something they normally do - so it was very kind of them, to bend the rules for me! Thanks guys!!

Finally, we were ready to go:



Ten years old - not bad actually...



18 external Torx bolts to go...



Thankfully, with a combination of the 3 P's, Preparation, Percussive shock from the air gun and Perseverance, all the bolts finally succumbed and wound out cleanly - I can't tell you what a relief that was!

I'd bought some Silverlake Titanium studs and K nuts to replace the bolts with, so they went in next, with anti seize, to make any future removal easier. New OEM gaskets were fitted throughout.



New Vs Old



Unfortunately, one oxygen sensor refused to budge and had to be replaced (OEM), which meant coming back at it the next day but in the grand scheme of things, that was a good result!

New manifolds in place and torqued to spec.



After testing.





After the new tips were fitted.





Initial Impressions
The HJS cats flow so much better and have made quite an improvement in how the engine responds. PSE has more of a growl in Normal and a HOWL in Sport but isn't offensive, even on cold start.

At some point I might get the car onto a Dyno but this was never about chasing a few extra horsepower (hard to do with an already efficient NA), so for now I'm happy with the way it sounds and if there's been a small increase, then that's a bonus.

Thanks again to Cargraphic, Design911, my long suffering friend Peter, the guys at Sports and Classic Ltd and anyone who read this far

Please Note: I have no financial interest in any of these companies and just report good service where I find it.

Til next time...may you enjoy your car in good health.

Mark Davis (AKA: 911Time)

Mark, a fantastic write-up. :thumb:
New manifolds looking (and sounding) superb. :lol:

Fabulous looking exhaust tips.

Thanks Gents :thumb:

Very impressive as always Mark! This is something I would like to consider doing in the coming years. I was thinking of Topgear as I've had one of their crossovers for the 997 and was impressed. What was the reason you ruled them out?

Would love to see a video if you can be bothered!

Looks really good, I love the seat trims, very nice :thumbs:

The Cargraphic exhaust looks good too, but I'm also curious why you went with those over the other ones you mentioned. On my 997.2 the Cargraphic ones would be 4 times more than Topgear, though its it seems to be 2.5 x for the 991 versions.

So I'd be really keen to know if you think the extra cost for Cargraphic would be justified if I was to change mine?

Great write up :thumb:

ps Can I borrow Peter :grin:

JonnieD said:

Looks really good, I love the seat trims, very nice :thumbs:

The Cargraphic exhaust looks good too, but I'm also curious why you went with those over the other ones you mentioned. On my 997.2 the Cargraphic ones would be 4 times more than Topgear, though its it seems to be 2.5 x for the 991 versions.

So I'd be really keen to know if you think the extra cost for Cargraphic would be justified if I was to change mine?

Click to expand...

The research took me so far in terms of material specs, tubing size & design, weld quality etc and identified where there was parity between products until finally, after ruling out the ones that in my opinion didn't offer enough extra to justify the higher price, the Cargraphic manifolds seemed to represent the middle ground. First class service counted as well.

Along the way, I also spoke with 3 long established Porsche experts, who gave Cargraphic their vote and mentioned running them on their own cars.

Having said all that, the Topgear manifolds represent fantastic value for money and lots of folks on here use them. I think there have been a few group buys, so that must say a lot!

jonttt said:

Great write up :thumb:

Click to expand...

Thanks :thumb:

jonttt said:

ps Can I borrow Peter :grin:

Click to expand...

He's a star but expensive to keep in beer

That looks stunning - love how elaborate 911 exhausts & manifolds are. Amazing the finish you (or rather your friend) managed to get on those, perfection!

Great write up and love the Mods on your car, looks OEM!

Very nice!
Individual choice but rear wiper delete would have been spot on

Thanks guys - much appreciated

Pete did a great job on the polishing and it still looks good under the car :thumb:

OEM+ was always the aim, so that's good to hear - thanks :thumb:

Looks superb 8)

911Time said:

JonnieD said:

Looks really good, I love the seat trims, very nice :thumbs:

The Cargraphic exhaust looks good too, but I'm also curious why you went with those over the other ones you mentioned. On my 997.2 the Cargraphic ones would be 4 times more than Topgear, though its it seems to be 2.5 x for the 991 versions.

So I'd be really keen to know if you think the extra cost for Cargraphic would be justified if I was to change mine?

Click to expand...

The research took me so far in terms of material specs, tubing size & design, weld quality etc and identified where there was parity between products until finally, after ruling out the ones that in my opinion didn't offer enough extra to justify the higher price, the Cargraphic manifolds seemed to represent the middle ground. First class service counted as well.

Along the way, I also spoke with 3 long established Porsche experts, who gave Cargraphic their vote and mentioned running them on their own cars.

Having said all that, the Topgear manifolds represent fantastic value for money and lots of folks on here use them. I think there have been a few group buys, so that must say a lot!

Click to expand...

Thanks for the update Mark.

Frightening though that the Cargraphic was the middle priced option

I guess that the USA (or non European) manufacturers are always expensive here though by the time you've added further distribution and customs duties etc.

I agree about Topgear though, and their deserved reputation here, they're great quality products and a UK manufacturer too which I'll always support if I can. I posed my question as I also want to replace the headers on my C4S. I've got the switchable TG system upstream of that already.