Piper Exhausts turbo downpipe development thread

[PiperRS]

Back on topic.

The first batch of downpipes has been completed! I have limited stock of the downpipes ready for dispatch. they come with a fitting kit which include 35mm Studs for the turbo as the OE ones are prone to snapping on removal.

These are available now direct from ourselves, for £190 +VAT. They are stainless steel 2.5" bore downpipes.

Please contact our sales team for more information. sales@pipercams.co.uk or call us on 01303 245300

[surfboardfiller]

Thanks Tom!
Do you have a price for ceramic coating the inside of the pipe?

I'd recommend it to anyone buying a pipe as stainless holds more heat than cast iron.

Cheers,

Phil

Weight comparison.jpg

[PiperRS]

Thanks Tom!
Do you have a price for ceramic coating the inside of the pipe?

Cheers,

Phil

Hello Phil, A downpipe with external ceramic coating will be £260+VAT, however it will be about 2 weeks until the coating process is finished.

[Monty]

Back on topic.

The first batch of downpipes has been completed! I have limited stock of the downpipes ready for dispatch. they come with a fitting kit which include 35mm Studs for the turbo as the OE ones are prone to snapping on removal.

These are available now direct from ourselves, for £190 +VAT. They are stainless steel 2.5" bore downpipes.

Please contact our sales team for more information. sales@pipercams.co.uk or call us on 01303 245300

Nice work and a good price too I`d have one if i didn`t have one already fitted.

My down pipe aka The Stiffy has a bracket so it can be bolted to the block to stop any movement

Btw, i had mine ceramic coated at http://www.camcoat.com/ think at the time it cost us £50 each

[ccb056]

I'm confused as to what the final design looks like. Cliff posted some pictures a few pages back (shown below) and they look different than the one posted above.

Does the final design have separate flow channels for wastegate and turbo exhaust?
This is a key design component that IIRC both Lotus and Knox incorporated into their designs to prevent the wastegate exhaust from interfering with the turbine rotation.
The photo above appears to have eliminated this design component.

[HJ2]

The Lotus design does NOT have a separate wastegate traject like the Knox design. It does however have a small deflector directly after the wastegate flange that directs the flow of the wastegate downward. The Piper one does not have any of these features.
I am currently in the process of installing a Piperdownpipe as i desperately needed parts to replace the damaged sections and it is now ready available, so for me... a puzzle for beginners and i am happy with it. !
It's all about budget, and the best bang for the buck.

I'll post some pictures later on. I hope to do a testrun tomorrow

[surfboardfiller]

The Lotus design does NOT have a separate wastegate traject like the Knox design. It does however have a small deflector directly after the wastegate flange that directs the flow of the wastegate downward. The Piper one does not have any of these features.
I am currently in the process of installing a Piperdownpipe as i desperately needed parts to replace the damaged sections and it is now ready available, so for me... a puzzle for beginners and i am happy with it. !
It's all about budget, and the best bang for the buck.

I'll post some pictures later on. I hope to do a testrun tomorrow

The Piper has a deflector in it (typo?) and has much improved gas flow over the Lotus/Original Equipment Manufacture.

ccb056,
None of the down pipes have an external waste gate (and that is a good thing).
Piper have developed the pipe further since Cliff's; to improve gas flow and fit.
When the waste gate is open the flow from the turbine is reduced so the 2 flows won't compete much anyway, however the small pipe from the WG has been reduced and the hairpin bend eliminated to improve the blend between the 2 gas flows better.

[Rice crispy]

Questions from the non mechanic
1) will this fit with any exhaust ? I assume so as its just replacing the section as per Phils picture
2) does it matter if the whole exhaust isn't 2.5"? I have a 2" stainless system I think at present
3) could this cause overboost ? at present i don't suffer overboost and would need to pay for someone to do the wastegate if it did

Thanks
David

[whippit]

I know i'm being petty but are there any support brackets for the heat shield, i can see only the top support strap to the manifold heat shield,
if it only has this it wont be there long, ????

[HJ2]

I am just back from the garage building a bracket from a strip of stainless, running from the existing right hand hole in the shield to the front nut of the PAS pump.
I think 2 points will hold as it is not very heavy. I have a trip in Belgium sunday (Lotus Summers end, anyone else attending?) so i will be able to report how it holds after some serious driving on not so serious roads

[whippit]

i like the look of pipe but for that money i might ask them to weld a couple of brackets on it, the pre cat has them already welded on for the shield,
i dont understand why there not fitted especially when as phil says stainless transfers more heat, after thought may be !!!

[ccb056]

Yeah, I'm also a bit concerned with the lack of mounting for the heatshield.
I would imagine there is a lot of radiant heat (as opposed to convective) generated by the turbine and the hood of the car is very close...

[Steve A]

I would be very interested in any feed back from someone who has got a downpipe on their car

[rip]

Questions from the non mechanic
1) will this fit with any exhaust ? I assume so as its just replacing the section as per Phils picture
2) does it matter if the whole exhaust isn't 2.5"? I have a 2" stainless system I think at present
3) could this cause overboost ? at present i don't suffer overboost and would need to pay for someone to do the wastegate if it did

Thanks
David

Answers from another non-mechanic who has read a little on this forum

1) I believe it will. My Piper 2¼" fit on my OEM downpipe. I suspect your 2" system fit your OEM downpipe too so any replacement downpipe should fit either or none.

2) The closer you get to the engine, the more critical the exhaust flow because you are trying to get pulsing gas flowing from 4 different directions to all go the same direction through 1 pipe. Turbulence is unavoidable, but the aim of this downpipe is to reduce it as much as possible, so it should still make a difference with a 2" system.

3) Very possibly. As mentioned above, the downpipe is much more significant to performance than the rest of the exhaust. The aim of replacing the OEM downpipe is to allow better gas flow. More gas flow means that you may need the wastegate to allow a higher flow than what it can actually cope with. The result is boost creep & eventually overboost.
On the other hand, the downpipe may reduce turbulance & allow gas to flow more smoothly through the wastegate (& therefore increase the maximum flow).

Turbulence is a black art for all except the extreme experts in the subject & I certainly don't claim to be one!

[Steve A]

Question:
Is the down pipe a direct replacement that will conect to a standard exhaust ?
i.e is the exit of the down pipe the same orientation and length as the catalyst housing (the big cast lump we're trying to replace)
or is it only designed to fit the Piper system ?

[dapinky]

Steve,

I don't actually have one, but as the whole Piper ethos has been to provide a 'modular' system then it is fair to say it should fit a standard system (or Peco, Quicksilver etc).

As the Piper exhaust will fit onto either the PCE or the standard PCH it is obvious that the flange has the same fittings and location os the original OE exhaust.

Therefore, common sence says that if the two endpoints are in the same places (wastegate housing at one end, exhaust pipe at the other), then the downpipe will be a straight swap for the PCH/PCE and the iron bit above it, and it wont matter what exhaust system is fitted.

(That said, I'm only guesstimating, and it may be designed for specific diameter(s) of exhaust pipe??????????)

[paulsmithmk]

I ordered a piper system yesterday exl down pipe (nexy job!) I'm sure if you call them they will discuss as were very helpful when I spoke to them yesterday

[PiperRS]

:? Question:
Is the down pipe a direct replacement that will conect to a standard exhaust ?
i.e is the exit of the down pipe the same orientation and length as the catalyst housing (the big cast lump we're trying to replace)
or is it only designed to fit the Piper system ?

Hello,

Our downpipe will replace the stock cat pipe, and will fit to either our exhaust system or the standard lotus system (and in theory a Peco or Quiksilver) This means that it can also be fitted at a later date and does not have to be fitted when the system is changed, and here is the pipe in question, posted here first, just for you guys

[paulsmithmk]

:? Question:
Is the down pipe a direct replacement that will conect to a standard exhaust ?
i.e is the exit of the down pipe the same orientation and length as the catalyst housing (the big cast lump we're trying to replace)
or is it only designed to fit the Piper system ?

Hello,

Our downpipe will replace the stock cat pipe, and will fit to either our exhaust system or the standard lotus system (and in theory a Peco or Quiksilver) This means that it can also be fitted at a later date and does not have to be fitted when the system is changed, and here is the pipe in question, posted here first, just for you guys

so I could fit this to my S2 and have a totally new system - am wondering if I should have odered after all now?!!

[PiperRS]

so I could fit this to my S2 and have a totally new system - am wondering if I should have odered after all now?!!

As mentioned, it can be fitted after our exhaust has been fitted (although it will be easier to do it all in one go!)

I have these in stock ready for dispatch if you wish! Il even offer you free postage with it! (saving £15!)