New Large Bore Exhaust by PECO for S1 Elans with no flat bit

[Paul.P]

David, can you make different end sections for the back box, not sure if i'm keen on the oval ?

[Monty]

just like to point out that the welds on our stainless systems are stainless and will not rust.
the only mild steel part on our system is the flange, the reason for this is that stainless flanges are prone to cracking.

Also like to say that this system does fit an S2 and it will still pass the MOT emission test providing your pre-cat is in working order.

Dave Jones
Head of R & D
PECO

David,

What about doing us LEC`ers a discount on the Exhaust system fitted and not fitted as i`ll be after a system hopefully in a months time once i get the gearbox and stiffy fitted.

ps i`ll be after a 2 1/2" straight through system with just the oval pipe (with out the inner one )

[stevieshag]

yeah i too would be interested in a 2 1/2 inch stainless for my SE, so if we are looking at discount for a group buy, consider me in..
stevie.

[ailwyn]

yeah i too would be interested in a 2 1/2 inch stainless for my SE, so if we are looking at discount for a group buy, consider me in..
stevie.

2.5" with oval (no inner pipe) tail for my S2, as long as the price is right

Ailwyn

[Dico]

yeah i too would be interested in a 2 1/2 inch stainless for my SE, so if we are looking at discount for a group buy, consider me in..
stevie.

And me (Dico SE)

2 1/2 is the way to go

[David]

We would certainly be able to offer a discount for an LEC group buy.
Various tail pipe designs are available.
The system is 2.25".
2.5" system is not available.

Dave Jones
Head of R & D
PECO

PS. we can also offer a Rolling Road day if anyone is interested.
£25 per car, minimum of 10 cars, maximum of 25.
Only on a saturday.

[ailwyn]

2.25" is not the end of the world.

Can you please post an indication of the group buy price so that we can decide. Might be worth putting up a list if there is going to be a variance based on numbers e.g. 10 = £x each; 7 = £x each; 5 = £x each.....

Ailwyn

[Dico]

2.25" is not the end of the world.

Tiz for me. Any future upgrades may benefit from a 2 1/2" exhaust and i only want to do it once.
Are you sure you can't acomodate for people intrested in a 2 1/2" set up David?

Mine or Montys Elan may be available as a guinea pig.

Note - Many 2 1/2" systems have been fitted previously on Elans.


Rolling road sounds interesting.

[stevieshag]

yeah i am with dico, if we are going to upgrade might aswell go for the bigger bore 2 1/2 inch system as only want to upgrade once.

[JIMBO]

I will be needing an exhaust later this year, and would also prefer to do it once. If 2.5" is the best way to go then count me in too. (that's just 1 exhaust)
Jim

[Dico]

1) PaulP - 2.5"
2) stevieshag - 2.5"
3) Monty - 2.5"
4) Ailwin - 2.5" or 2.25"
5) Dico - 2.5"
6) JIMBO - 2.5"

Got to be worth a go David?

Any more intrested parties please cut/paste and add your name to the above.

[Paul.P]

Did i say 2.5 ?, wouldn't mind though if this goes ahead ?

[nitroman]

I had boost creep with the stock turbo at sea-level with Bill's 2.5" IsuzuPerformance system & no cats at all. This was solved by using a single 2 1/4" gasket at one junction. It was also solved by moving to 1000-feet above sea-level! *

In any case, there is a difference between 2.5" & 2.25".


On another point Porsche uses a round inner outlet on their rather unique oval exhaust outlets, so I have no doubt the PECO man is correct that it smoothes the exhaust-flow.


* - That is why I am installing the larger T-bird compressor-wheel & housing which is a bolt-on upgrade to the stock turbo. It flows 388CFM of air vs only 200CFM for the stock turbo. I'm also machining the wastegate outlet from 16mm to 22mm to make sure I don't re-introduce boost creep again. This seems like a logical upgrade since it is the most you can do to the turbo without having to install larger injectors or fiddle with the ECU. Also there are several companies which supply the wheel & housing as a kit as it is the ultimate IHI RHB5 upgrade for a host of cars using this turbo.

[David]

Hi all

I drive an M100 as my everyday car so the guinea pig is not a problem.

The problem is at this moment we do not have the tooling to bend 2.5" T304 stainless tube on our mandrill bender. We can bend it on a compression bender but as you probably know this reduces the diameter of the pipe on the bend making the whole exercise pointless. It is possible that in the near future we will have the tooling to do this, I will keep you informed.

Dave Jones
Head of R & D
PECO.

[davidjt]

According to everyone I've spoken to, 2 1/4" will flow perfectly well up to 250bhp; 2 1/2" looks butch, but really isn't necessary.
Unless of course you're chasing Costas, in which case, Good Luck!

[Nige]

According to everyone I've spoken to, 2 1/4" will flow perfectly well up to 250bhp; 2 1/2"

That is exactly what my exhaust builder told me as well. However I agree with the sentiment that if you're going to upgrade only do it once.

[John_W]

All,
My 2p’s worth on this is that a 2-1/4” exhaust is all you need. I’ve examined data from dyno runs and ElanScan logs for cars with up to 2-1/2” exhausts and Everest chips. If you are planning to fit a bigger turbo or go over 215 BHP, then I have no data to allow me to comment (but I still think 2-1/4” should be adequate).

The standard exhaust system on the Elan is made of 2" pipe with an 8" long squashed section over the front frame which takes it down to the equivalent of a 1.75" diameter pipe (I've measured it). There is reportedly another restriction within the silencer (which I have not measured). Larger exhausts commonly fitted are 2.25" or 2.5" diameter.

Hereare some pictures

It is worth noting the cross-sectional areas involved:
• 2" diameter (standard): 3.142 sq in
• flattened section (standard): 2.5 sq in
• 2.25" diameter: 3.976 sq in.
• 2.5" diameter: 4.909 sq in.

Thus the squish loses 20% of the cross-sectional area of the standard exhaust. Therefore, although the 2.25" exhaust only increases cross-sectional area over the standard nominal 2" pipe by 27%, it effectively increases the area over the squished pipe by 60%, and the 2.5" exhaust offers a massive 96% increase over the squished standard pipe. All of this means better breathing, but how much do you need?

From dyno and “30-70 full throttle in 3rd” datasets I’ve examined:
• Using the standard chip with the standard exhaust gives an ultimate boost of 0.56 bar, well-controlled and constant. (see pink dashed line here )

• The standard chip with the 2.25” exhaust shows incipient "boost-creep" above this 0.56 bar level after 5 secs full-throttle acceleration (see red dashed line here and also the red solid line here marked “standard boost 0.56 bar”) Doug’s 2.5" exhaust shows the same creep effect when using a standard chip and no mbc (light blue dashed line here).

• The Everest V3 boost falls off after 13 seconds of full throttle, see 731 secs here. I regard this as the turbo running out of puff as its delivery limits are reached (but somebody may have another explanation). Once you’ve been on full Everest boost for 13 secs you’re going quite fast, so this is from a dyno run.

Note that my exhaust is 2-1/4” but not mandrel bent, therefore a mandrel bent exhaust will produce results at least as good.

So what?

I reckon that once you’ve lost the squish, you’ve done most of what you need to do. Improving the breathing by using a 2-1/4” exhaust works well, and mandrel-bent will give a true 2-1/4" even round the bends. In the limited data I’ve seen I haven’t observed any benefits form the 2-1/2” exhaust over the 2-1/4”. If a 2-1/2” exhaust is more money and more hassle, why bother?

John

[Monty]

Most places don`t charge any more for the 2 half inch + it no more hassel. The only thing i was worried about was losing power by going bigger, but stevo has no problems with his. + maybe one day i`ll go for the 260 bhp

Blueflame quoted me £425 and that was having the pre-cat replaced, all fitted and life time garantee. But now got the stiffy and hoping to get the rest of the system for £300

[Avonvilla]

One thing to bear in mind that no ones mentioned is a bigger exhaust sits lower so grounding is easier, i grounded my 2.25" several times but the 2" never and would assume a 2.5" would be slightly worse, just a thought.

[John_W]

Most places don't charge any more for the 2 half inch + it no more hassel.

Monty,
if that's the case then go for it. I just couldn't see 2-1/2" being an absolute requirement for any sensible power output.

You're right to mention the stiffy/wastegate enlargement, as that should get rid of the creep seen in all the graphs I refered to.

John