Exhaust Overpipes

[Keethos 842]

Hi,I've been advised by Mark from Abbey Motorsport that an overpipe for an N/A engine isn't worth the money, anyone on here in the know agree or disagree? What are the benefits of an overpipe? Is it just better flow which should mean better performance but because it's an N/A engine, the gains in minimal? How much gain are we talking? Would it feel any different? Makes more sense on a FI engine I assume?

[GT86-Ian 351]

You wont gain much with just a new over pipe, If you go F1 you should really change the complete exhaust, all depends what your plans are keeth... If I go F1 or stay n/a with a new manifold the over pipe will be changed.

[Lauren 2259]

I did it as part of the decat. As for gains, well, it's just hard to say. As with all these things you need to see how it complements other mods. It is less restrictive flow wise from a visual perspective. I noticed that when I did the decat and overpipe it made the exhaust a fair bit more vocal. I didn't do a before and after comparison on the rollers so I don't really know, but I think losing the 2nd cat certainly freed up the exhaust somewhat and seemed to improve throttle response.In summary I wouldn't bother with just the overpipe, but if you're doing a decat you may as well do the overpipe as well.

[Keethos 842]

That's the thing, I'm looking at getting the Cobra Exhaust system, non resonated with the cat delete. I originally included the over pipe but Mark said: "To be 100% honest on a N/A car the over pipe is a waste of extra money". So just wanted a second opinion really. There are no plans to go FI any time soon so if there are no real benefits then may save myself some cash!

[Lauren 2259]

Well, I guess it's one of those things. If it adds a fair bit to the cost, it may well not be worth it. I'm sure Mark is right, gains would be minimal. But, remember it is shiny.

[Special K 442]

Keethos - speaking from memory I think the OEM is somewhat 'squashed' where it avoids the bellhousing. As part of a (secondary only decat) full system it is debatable whether it is worth it - I'd agree with Mark - I went for the (both cats deleted) and replaced with an overpipe, high-flow cat in the midpipe and non-resonated system - which is the only way to go if, like me, you want to replace your exhaust headers with a non-catted system (or turbo) and want to remain MOT legal. Spec K

[GT86Jay 202]

Keethos, As you know i've got the full Cobra Decat system. But didn't go for the overpipe. Cobra were still in development with it when I had my kit fitted. They've said I can go back and fit it at anytime within my initial cost. But to be honest. I saw most the improvement with the 2nd cat delete! The thing flows so much better. I will eventually go and get the overpipe. I know Fensport are developing some or 'working on making' some. Not sure what this entails yet. But i'm in no hurry to change. You certainly will not be disappointed with only the 2nd cat delete system! When I change the overpipe in the future i'll report back on the differences. I may even just go with a Miltek overpipe. It'll be cheaper than driving to sheffield to get the overpipe fitted. Or see if Mark@Abbey can sort me one through Cobra.Unless you've got $$$ to spend. I wouldn't worry too much about the overpipe at this point.

[Riceburner 284]

The overpipe will make a difference if changed as part of the full flow system be it cobra or Milltek because the OEM is restricting the flow.To get the max benefit though Ecutek remap is required but I recommend to change it.

[Special K 442]

Can I just mention that Mark@Abbey prototyped an OEM exhaust manifold for me with the cats deleted... this made a significant difference in bhp over the standard kit but, to take full advantage of it, the overpipe/midpipe second cat needs removing/replacing with an HFC. Mark was talking about offering this modification on a part-exchange basis - not sure how far this plan has progressed but he has the jig for it... (I still have this manifold if anyone is interested in it - replaced with turbo). Spec K

[rob275 1817]

Adrian also told me not to bother with it as the gains for the price was really not worth it, which is cool, saved me £170 odd

[Riceburner 284]

I disagree any small gain is a gain so change the overpipe and move on to the next

[rob275 1817]

This is you, but personally for an increased airflow of maybe 1 or 2 grams or whatever it is for near on £200 it's not worth it in my opinion unless you really are doing extensive N/A or F/I tuning. As i won't be for the foreseeable future it wasn't worth it. It all depends on peoples future plans i'm sure you will agree.And probably how serious you are going to be taking the TSS if you take part in it.

[Keethos 842]

Well I think I've got my mind made up and guna save some money by not getting the overpipe, thanks everyone for your inputs. Since my main goal is getting some more sound out of the exhaust, whatever gains would be great, but since it's not my main priority, unless the overpipe changed the sound dramatically then I'm not chasing every little bit of performance, especially for that price. If I was to change the manifold then I'd probably change it, but I can see myself doing that any time soon.

[toyokid 27]

side by side with a 2.5" replacement

[Keethos 842]

:+: awesome, thanks for the pic. Mark e-mailed me 2 pics, one of each and like others have mentioned in the past, the OEM one does look proper battered to fit correctly, but again doesn't improve much by replacing it.

[GT86-Ian 351]

So your not going Turbo then Keeth

[Keethos 842]

LOL, no time soon I'm afraid, definitely can't afford it now, thinking IF I do, it'll be in about 3 years time when I might start to get a lil bored of the car, if there's nothing else out there that tickles my fancy, bam, turbo, body kit the works! :32 (18):The question is when will you be turbo'ing yours? You've got the awesome looks, now you need the boost :32 (17):