Sports exhaust manifold exaggeration?

[Blufreak]

"at least 10bhp", does this sound right for just an exhaust manifold on a car that as standard is sub-100bhp? it will be accompanied by an new exhaust system too but want to make sure of how much bang-for-my-buck im getting

PEUGEOT 206 1.4 1.6 8V 4-2-1 TUBULAR STAINLESS STEEL RACE EXHAUST MANIFOLD 98-10 | eBay

This is likely the exhaust

http://www.ebay.co.uk/itm/PEUGEOT-20...item2eb864d6f4

[chopper1192]

A good tubular manfiold can give a little, but not nearly 15% gains! In general terms, exhaust and inake mods give a touch more power, but the biggest effect they have is to shift the pwer around the rev range rather than give much more area "under the graph", as they say.

A 10BHP gain on an engine that has to clench its buttocks and get a good run up to develop even the claimed 75BHP is hokum I'm afraid. It's a smooth unit and can be economical if driven delicately, but it is the slowest accelerating engine in the current PSA range (it's still in use in the 207, but even the far from rapid 107 kicks it in the nuts for acceleration).

These motors don't respond well to tuning, and you'd have to bin the stanard management in favour of seperate TB's or quad carbs to open it up, and even then you'd be spending a fortune and would be lucky to get it far North of 100BHP.

Keep the engine well maintained, but any ideas about more shove should be set aside in favour of a faster car.

[Blufreak]

yeah,was never expecting it to be the ferrari of the hatchback world,just want to liven it up a bit really. besides,go too far and it'll be sat on my drive going nowhere for want of funds to insure it

bodyworks much improved over the last month. only thing thats driving me mad is HOW THE HELL do you remove/disconnect/destroy the roll-pin that holds the brake-stem onto the servo inside the car? everythings ok apart from that one bit i just cant get it off hmmmf

[Blufreak]

quick question, the manifold i posted doesnt appear to have the place to fit the sensor that is in the standard manifold. is this going to cause me much of a problem? any recalibration work etc that would need doing if i cant install that sensor?

[Bird dog]

Originally Posted by Blufreak

quick question, the manifold i posted doesnt appear to have the place to fit the sensor that is in the standard manifold. is this going to cause me much of a problem? any recalibration work etc that would need doing if i cant install that sensor?

Car won't run right if sensor isn't doing its thing.

Chances are that your new manifold won't give you any increase in power at all, since it was probably already flowing well enough with the original one.

It used to be that these things were always worth replacing on cars from years gone by. Back in the 60's, 70' and 80's, things like manifolds and exhaust systems were very, very restrictive. But these days most engine manufacturers already fit cars with exhausts manifolds, inlet manifolds, exhaust systems etc, that can easily handle what's being thrown at them. But that doesn't stop people from trying to sell you something that in times gone by would have been a no-brainer mod.

As an example, I once witnessed two similar cars on a rolling road. Both were Vectra 1.9 cdti's. One had a K&N filter, air box mod, decat, and DPF removed (nice estate car, 75,000 miles) and the other had a dirty air filter, cat, and an 80% blocked DPF (a bit of a dog to look at with 180,000 on the clock). Neither was remapped or boxed. Both put out bhp figures within 2 or 3 bhp of each other on all runs and the torque figures were similar too.

So, unless you plan on pumping lots more fuel and air into your engine, it's not worth the bothering with things like manifolds etc.

[Blufreak]

Ok i've checked out the maifold,it DOES have the space for the lambda. Not to be disrespectufl but i find it hard to believe that performance exhausts/manifolds etc offer no improvement on performance whatsoever. It would render them pretty much obselete as they just wouldnt be bought as it would be common knowldge by now among tuners etc. and i dont see manufacturers pouring money into parts like that to release all the potential from the engine,maybe on GTI etc but not on a 1.4 quicksilver. surely better/larger flow of gases is a positive in that respect?

Secondly, the current bogo one is slightly beggared anyway as you can see so it needs replacing and the new one is shineeeeeeeeeeey and pretty,means i can do away with the butt-ugly heat shield

[Bird dog]

Originally Posted by Blufreak

Ok i've checked out the maifold,it DOES have the space for the lambda. Not to be disrespectufl but i find it hard to believe that performance exhausts/manifolds etc offer no improvement on performance whatsoever. It would render them pretty much obselete as they just wouldnt be bought as it would be common knowldge by now among tuners etc. and i dont see manufacturers pouring money into parts like that to release all the potential from the engine,maybe on GTI etc but not on a 1.4 quicksilver. surely better/larger flow of gases is a positive in that respect?

I've seen kids replace a complete DPF/CAT system on a diesel with a full free flow system and not see any gains at all. I've also seen the same thing on petrol engined cars. In other words, the DPF exhaust on a diesel car has more than enough gas volume capacity as standard so that even when the DPF is ready for regen, the performance of the car isn't affected at all. There seems to be some absurd reasoning by some people who think that the more the DPF fills up the less power the engine produces! Thicko's! This doesn't fit with the time that one kid came in with a fully blocked/knackered DPF and still hit the bhp figures that you would expect to hit!

The standard exhaust manifold on your engine doesn't look that restrictive, which is what most manufacturers are capable of doing these days. There seems to be some feeling that engine manufacturers aren't capable of designing decent inlet and exhaust manifolds for their engines at present, even though they know better than we do how they work!

Originally Posted by Blufreak

Secondly, the current bogo one is slightly beggared anyway as you can see so it needs replacing and the new one is shineeeeeeeeeeey and pretty,means i can do away with the butt-ugly heat shield

The fact that yours is cracked means that it needs replacing. Maybe the heatshield was for a reason? And you may have it upon the 'bling words' as to why so many of these things get bought these days.

[Blufreak]

Fair point on the bling but but then why spend on "performance parts" that dont look the part hey,theres always strange things like that,i've had old knackered cars that still went like the day they came off the floor,and much newer cars that might aswell been driving round with the handbrake on despite looking like its in perfect nick........ partly depends on how the cars been driven. Nanny it and its gonna flop when you grill it. Grill it too much and the whole thing goes to pot.

Yeah that manifold def needs doing and is on the menu anyway,rather fit a shiney aftermarket one and chance some extra bhp along with a nicer sound than spend almost the same on a bogo ugly peugeot thing

[Bird dog]

Originally Posted by Blufreak

Yeah that manifold def needs doing and is on the menu anyway,rather fit a shiney aftermarket one and chance some extra bhp along with a nicer sound than spend almost the same on a bogo ugly peugeot thing

Probably the 'bling' part is much cheaper than a brand new part from Peugeot ? But there are plenty of good'uns around in the scrap yards.

Unless you also alter the engines fuelling in some way, it's very unlikely that you'll see any gains. Peugeot will have mapped the car to be well within all the tolerances of the intake, combustion (engine), and exhaust system capacities that were fitted as standard. They run these motors for hours on end on proper dynamometers to get the mapping just right, so that the engine is running as efficiently as possible.

[chopper1192]

Originally Posted by Blufreak

Ok i've checked out the maifold,it DOES have the space for the lambda. Not to be disrespectufl but i find it hard to believe that performance exhausts/manifolds etc offer no improvement on performance whatsoever.

On it's own, I find it very easy to believe in little improvement, if any. The laws of thermodynamics tell us so. At the very best, any gain you see will be at the expense of losses elsewhere in the rev range. You can take that to the bank.