stainless steel exhaust maniflod

[Jonathan]

I dont think you can be too critical of the manifold - your car is heavily modified, my stock car has done 45,000 miles, I beat the nuts out of it on a regular basis and its still on the original manifold. I agree they're not perfect but some of them seem to be reliable.

[Bibs]

If they were that bad then I'm sure Lotus would have had many warranty claims about them which they didn't. No car manufacturer really expects their cars to still be as good as new at anything up to 10-20-30 years old and if they did the manifold would weigh 8 tonnes. 'Cake/eat it' problem.

[waynef]

Bibs i'm shocked your car does not have the issues with manifold as you rag yours probably as much as mine.

I agree cake and eat it but then I guess one could say if all else is modified why have I not modified manifold.....answer) one does not exist lol.

Till then its just an achilles heel

Dave my car is going in next week on tuesday how far down the development route has this company gone, also are they going to make the headers of equal length? as this is really important to the performance?

Just out of interest how much is this costing as I would be willing to make a financial commitment and testing of this manifold for all to benefit. Theoretically we should be able to reduce exhaust gas manifold temps considerably by going to a tubular style. Keep me informed

Waynef

Edited August 13, 2009 by waynef

[Jonathan]

Keep in mind by reducing the temp you pass it on to the turbo and the cat (if you have one).

This is my issue with turbos/chipping and so on - I know of so many standard cars with no real issues and very good reliability, that said I dont drive mine hard in the rain and my car is pretty much alwasy garaged and kept out of the rain at home. I wonder also what affect the wide tyres on the back has affect on road spray....Mine does get a lot of rain use (when ever I drive it, it seems) but I never drive past 50/60mph on a wet road (ie when you can see spray from the other cars wheels / rooster tails).

In the dry however, well it gets ragged probably as much as any other.

My turbo glows orange most times (must take a picture, keep forgetting but it's really pretty as the orange parts are in the recess, looks like a thermograph picture).

Whilst I totally agree with and applaud people going out and trying new things, I do think certain parts of the engine are stressed to 90% their limit already - keep in mind this is only a 2.2 (in my case 2.0) producing more than 100hp / litre. Alright the Jap cars produce more than that but again I've seen them broken down by the road side by the dozen too so I'm not really that convinced.

I think if the car was stock and you had this problem again and again then Lotus would have a case to answer for, but there are a fair few cars out there without these issues.

I really hope someone over here manages to 'crack' it though - having the option to chose would be a huge benefit and a serious gift for some of your wallets !!!

[Dave Freeman]

We are still in the very early stages on this one. But I am as confident as I can be.

Due to my holidays and the suppliers I do not expect

to see much progress before the end of sept. I will post comments and pictures as they become available.

Take care all - happy holidays. Iam back late august.

Dave

[Bibs]

My manifold is fine (touches wood) and it gets so hot it glows enough to read a book by and that's just on a trip to the shops. I warm up and cool down the car religiously and it doesn't get ragged until it's fully hot plus it's not as much fun until the boost gauge needle is bending!

A tubular manifold is an advantage on an NA car as the pulses are tuned to scavenge. On a turbo car, the important thing is that the manifold is as small as possible and the distance to the turbo is as short as possible. Hotter gases are good, the hotter they are the quicker they wish to leave therefore the more (efficient) boost due to higher pressures.

[Jonathan]

All true - I also warm up and down and also dont put the boot in until it's warm (no point anyways becuase the play boost is not there).

The fun for me is to get the turbo glowing by the time I get up the drive, but I wait until it's stopped before switching off, couple - 5 mins at idle.

[Newts]

Hi Guys

A little information about the chap who's building this manifold for us. He's heavily into his Jap cars and runs a small business. He has built quite a few including one on his 700bhp Prelude (which he is now uprating to c1000bhp) another for a 1200bhp Skyline and a complete system for a heavily modified trackday RS500 Sierra Cosworth. All of these run Turbo's the size of dinner plates and the manifolds glow red/orange. He also makes his own design induction kits have been checked on Dave Walkers Dyno and produce 7bhp more than the K&N kits.

Anyway it a bit trial and error but we think its worth a shot...

[Jonathan]

Definatly - really hope it works !

[Bibs]

What's he charging?

[Dave Freeman]

Be happy to tell u thro pm but not sure it's right to broadcast on the forum

Also he has not confirmed the final price.

Dave

[red vtec]

Out of interest does anyone know what temps the N/A manifolds run at ?

[s4s]

Hi Waynef, SS header of Patpong's yellow S4 just broken last month. The broken point is at welding spot at turbo flange. This SS header was just last only few thousand Km. Our cars has full mods, I can say 350+hp, Marcus knows it very well. When we go out for sunday drive, we floor the throttle from 3rd to 5th gear all the way to 260 kph and killed all F cars. Mine has cast iron. Patpong has SS manifold.

I used to have replica X-180 SS exhaust pipe from Marcus on my car. It also cracked at welding spot at muffler. This one last around 40,000 km.

Temperature at muffler is by far lower than at the header.

I saw many aftermarket SS manifolds for Porsche turbo. May be they know how to make it.

[Newts]

I think one of the main differences between the cast and SS manifolds, is that if the tubular one cracks it can be relatively easily repaired.

[OwenGT3]

Hi,

Agree Newts, this why I like my manifold, I've repaired it and it's still going, wouldn't have been possible with a cast one.

From what I understand, is it Power and Performance of Honingham making the manifold? The same people who make my exhaust and who I said I would get in another thread to look into making me a manifold for my car when I need one, similar to my spec already fitted.

Owen

[Dave Freeman]

Hi guys, to ensure that my supplier has all the facts and envolves everyone Whois interested he will be joining the forum so please welcome Nathan when he joins, the more help we can jointly provide the better and it will help us all, please look out for "I-tune" real name Nathan.

Take care

Dave

[Dave Freeman]

Well, I am happy to share any information I have regarding this new manifold, but it would appear that there are others on this site who are not prepared to share, that's a bloody shame and shameful. I understand that some other member has flange details for the new manifold but is not willing to share.

We can manage on our own, do not worry, we will share our finding with everyone

best regards

Dave, at the airport flying out at 7am

[mr.oogieboogie]

perhaps those may know something do want to share, but dont want a rough ride like dr hess. seems the topic has gone from it wont work to lets see if it will work and now lets try to get it to work.

[Jonathan]

Hang on a sec, no one gave anyone a rough ride !

Problem is you hear about people making these things - they go 10,000 miles without a hitch and then they disappear without any clue as to how it lasted.

People are talking about Patpong's manifold but he's gone off later to find his one has cracked too. I really like what people make and I admire the effort they put into them - would I buy one, nope - would I fit it to my car, probably not. If it works for them - superb, I couldn't be happier that people are enjoying their car once again !

The issue is when you look at say my GT3 car, it's done 45,000 miles over 12 years no manifold issues. Take my car as an example and you'd have to do over 12 years of testing/use until I'd get a good gauge of what works and what doesn't, that's totally unrealistic. The point also is I've never heard or seen anyone who's made an aftermarket exhaust manifold that can claim the mileage my standard one has done.

If my manifold cracked tomorrow and someone offered me a largely untested tubular stainless one at

[red vtec]

As know one has bothered answering my question i'll ask again,

What temp does the N/A Manifold run at? is it lower than the turbo manifold? as I know you can get SS Manifold for that application. If it operates at a similar temp it would indicate that it is the weight of the turbo that causes issues. ie the weight when the iron is soft with heat is causing stress issues. But if it a lower temp it would indicate that Temp is the problem. if its the former tahn it must be solvable with a Turbo bracket.

Does the Esprit run its manifold a lot hotter than other appliactions?

[cobraesprit]

Turbo engines exhaust manifold run at alot higher temperature.

I think that the main problem with the cracking is down to the mix of materials with different thermo-dynamic properties, in other words because the manifold expands and contracts at different rates to the cylinder head this causes the problem

I think that is correct...... someone will let us know if i'm wrong !!!!!!

[Newts]

Chris,

No Idea on the temps of the N/A manifolds, although they are a fair bit bigger as they have to have equal length primaries to maximise power output and exhaust gas pulse and flow.

This manifold will have a support bracket along the lines of the other two we have seen to support the turbo. Dave is also planning to have a flexi-joint inserted into his exhaust after the Turbo as is the norm' with modern systems as the engine vibration/movement moving against the exhaust could also be a contributing factor to tubular manifolds cracking.

One area I am still thinking about is the flange. What are thoughts on keeping it a one piece, or once completed, should it be split into four as with the cast one ?

[OwenGT3]

I've had no problems with my four separate flanges. Sorry don't have a template of the flange shape, didn't take one when it was off otherwise you could have it, but sorry I'm not taking the manifold off just to get one! If I remember rightly mine just follow the gasket shape, just a little bigger.

Owen

Edited August 16, 2009 by OwenGT3

[andydclements]

And considering the stainless will have a very different coefficient of expansion to the ali head the bolt holes (and probably appertures) will need to be elongated in order for the head and flanges to move against each other.

BTW, Dave, unless your car is very weird, the exhaust is mounted to the engine by way of the engine and gearbox being fixed, the exhaust carrier is mounted directly to the gearbox, so the exhaust is not mounted to the body.

Thus the flexi shouldn't have to cope with the engine moving relative to the exhaust. Having said that, there will be more expansion in the lenght of the exhaust than the gearbox (although ali expands more relative to temp, the exhaust will be several times the temp of the gearbox), so a slip joint after the turbo may not be a bad idea. Ditto, a slip oint before the turbo could help to reduce the strain on the manifold if the turbo is supported directly off the gearbox.

[Dave Freeman]

Thank Owen appreiciate your comments, Andy good point about the exhaust, but just to be sure, mine is mounted on rubber bushes as I think it should be the flex joint is to ensure no load comes from the exhaust. Colin, if the manifold flange was in one piece then if there were a problem it could be seperated.

Great holiday will be posting some pics later today.

Dave