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

[RatHead]

No its fine - not to loud at all. Its quietened down after just a few short drives already like yours has. As for long journeys - when I had the car on the motorway the noise level was only slightly higher than standard. Im pleased with it so far.

[Dovey]

It seems Jimbo's exhaust has highlighted a problem with his Elan

Speaking of exhaust and chips (yum) Alan says his chips don't stop boost creep. But if the boost creep is only to 0.7 say with this exhaust, can you just stick a chip in? Will the boost creep still happen when it's boosting at 0.8? Or will boosting at 0.8 overide the boost creep? Am I making any sense?

[GeoffSmith]

Sorry to hear about Jimbo - any details?

You are right that the only way to cure boost creep is to port the wastegate.

Having said that, using an ESM chip would probably mask the symptoms (as you suggest) for my everyday driving, as the overboost appears to be moderate. However, I reckon it would be dangerous not to cure the problem, because that odd time you floor the throttle is probably the time you don't want boost creep and fuel cutoff - the though of cutoff with oncoming cars doesn't bear thinking about!

Mind you if I had left the Superchip in, it would not have cutoff with any level of overboost, but that is a recipe for disaster IMHO.

Geoff

[Enright]

I couldn't agree more - I think you hit the nail on the head with every point there Geoff.

The biggest problem with wastegate porting is siezed fasteners. Turbo to manifold, and pre-cat to turbo.

And the very worst 3 are the pre-cat to exhaust ones, which you've just had shifted anyway.

So don't wait too long to do the job (i.e. get it done before they sieze again), and you'll find a detailed write-up of my experiences of doing it in Stevo's Stiffy thread.

[Nige]

You are right that the only way to cure boost creep is to port the wastegate.

Having said that, using an ESM chip would probably mask the symptoms (as you suggest)

Agreed, but Alan raised the fuel cut off level in his Everest chip to (IIRC) .98 Bar from the stock .92 bar. I have a 2.25" custom built exhaust and an Everest chip and do not hit the fuel cut off (and I do try sometimes!). Porting the wastegate is indeed the only way to cure the problem, however in my experience an Everest chip and a large bore exhaust combined means that you don't get the symptoms. I haven't been able to run Elanscan for a while as I no longer have a laptop but when I did it also indicated that the more effective boost control of the everest chip was a factor in not hitting the fuel cut level of boost.

[Dovey]

Sorry if this seems off topic but I think that a chip is the next progression for me, after the exhaust. That's why I brought it up.

Sounds perfectly reasonable to me Geoff. On the other hand porting would be a pain, and so I find Nige's words incredibly soothing. If the chip can control the boost like that in my Elan it would be ideal. I guess I could try it. Lincolnshire is full of old aerodromes which are handy for testing

[ab2cv]

Interesting discussions. Given the choice then, would it be better to get the garage (as I have no intentions of doing it myself) to port the wastegate at the same time as fitting the new exhaust or would that money be better spent on the chip instead?

Alan

[GeoffSmith]

No need for apologies Jay. Good to hear of another satisfied Peco customer!

Having experienced the full might of 1 bar boost, I'd recommend anyone considering upgrading to ESM's chips to seriously consider a brake upgrade (better be quick if you want F1 LOTUS's superbly engineered solution). It was very easy (and quick) to get to wholly inappropriate speeds on the back lanes to work and the stock brakes left a bit to be desired.

I'm not doing anything on mine for the time being, so I'm going to think about whether to open up the wastegater or not - my gut feeling is that it would be better to compensate for the exhaust but as Nige says, it doesn't look like it is too much of a problem if you don't. One thing I might try is to put the Superchip back in to inhibit the fuel cutoff and perform some Elanscan runs to see how high I can get the boost when it starts creeping.

It would be good to hear from others who've upgraded the exhaust before re-chipping.

Neil, I keep forgetting to ask you, but are you still interested in the Peco flexi pipe at £75? I need to talk to Dave and it would be nice to confirm one way or the other.

Geoff

[Monty]

Been back to Peco today as my Exhaust was a little to load and think this was down to having a stiffy fitted. So Dave has fitted a 2nd Silencer in where the gap where the main cat would sit in an S2 and has just taken the edge of the exhaust note.
As u know Dave is trying to develope a system with a Maincat for the S2 but he`s going to try and design the system were u can put a cat or silencer or just have completley without. But this would all depend on if new jigs would have to be made etc. Obviously the 2nd silencer and cat will come at extra cost.

[JIMBO]

It seems Jimbo's exhaust has highlighted a problem with his Elan

Speaking of exhaust and chips (yum) Alan says his chips don't stop boost creep. But if the boost creep is only to 0.7 say with this exhaust, can you just stick a chip in? Will the boost creep still happen when it's boosting at 0.8? Or will boosting at 0.8 overide the boost creep? Am I making any sense?

Woa, hold on,
I'm not saying the exhaust has caused the problem, just that it is the only thing that has been changed. I am very happy (but a little deaf) with the exhaust. My Wife can now hear me coming home from half a mile away and has a cup of tea ready for when I walk in. Now that's what I call a result!
The problem could have been there when I bought it, and is showing up now because I am driving it harder.
Regards
Jim

[algirdas]

Dear David at PECO:

Just for my own education, how much of a silencing effect does a catalytic converter have in comparison to a second silencer? I ask this because I see my car someday having a Stiffy (Stiffy II for the air-conditioned lot) and because I motor in wide open spaces, the droning of too loud an exhaust could become a bit wearisome.

And, for whatever it is worth, I like the idea of a "drop-section" where we can simply bolt-in and bolt-out either a straight pipe section (as in track days), additional silencers (day to day use) and catalytic converters (emissions testing days).

Sincerely,

Algirdas

[Enright]

Geoff,

Sorry, I should have confirmed one way or the other earlier.
I don't think that the price is unreasonable, but I need to spend my money on other areas at present, so I'm going to have to leave it for now.

Jimbo,

I am sure that the exhaust HAS caused it, and have heard of lots of others who experienced the same with any larger bore exhaust. It just surprises me that it doesn't happen to everyone.

The boost creep issue for some and not others really is an odd one. I had a K&N insert and Everest chip installed already and had experienced no problems. But after fitting Avonvilla's old 2 1/4" system (which seems quite similar to the Peco), I regularly hit the fuel cut. Switching back to a standard ECU (I have a spare) was no better at all.

Porting the wastegate to 20mm completely cured it. However, I quite understand why this would have been ridiculous to perform on every car as it was built. It must have been far easier to "engineer" a squish into the exhaust to match it to the turbo instead, which I'm sure is exactly what happened.

Bit of a bugger to have to engineer it out again after 15 years of heat cycles, but at the same time, quite progressive for a bunch of amateurs on a website!

[GeoffSmith]

Thanks Neil - fully understand the financial bit especially!

I'm hoping to talk to Dave tomorrow and I'll sound him out about this - we've stuck to our collective word and bought more than 10 systems and hopefully there should be some sales of S2/Fed systems later on, so he may keep the offer open for longer.

Geoff

[GeoffSmith]

Link to ESM info on boost creep and big exhausts

[Dovey]

Sorry Jimbo, I did not mean to give that impression. I did refrain from using the word 'caused'.

It seems this overboost is not a black and white issue. So to port or not to port? I reckon the car will make up my mind for me. Fit exhaust, test. Fit chip, test. If it hits fuel cut off, port. If it doesn't, be smug.

[Dovey]

Oh yeah, then buy new head gasket

[johnbenk]

Hi

Have you tried using Shell Optimax, or BP Ultimate.?????

With my Peco exhaust and K&N filter the car hit the "rev limiter" when
flooring the gas pedal, never had a problem with "boost creep" the Boost gauge hits 0.75 bar just as the rev limiter cuts in.

Dont do this often , but the power is better on this grade of fuel lower down the rev range and runs smother.

Just an idea to see if the BIG BORE EXHAUST likes higher grade 97-99 ron
fuel. as the gases are flowing more smothly from the engine after firing and going out through the exhaust without the flat bit.

[ab2cv]

Peco system ordered up and being dispatched to me today - it should arrive Monday (looking forward to it ). Then I just need to find a 'reputable' exhaust fitter to fit the thing for me.(not looking forward to that bit)

Alan