44 replies to this topic

[void babydoll]

Am I a dumb blonde...well I'm not really I know a little about cars but my boyfriend is trying to talk me out of having a twin exhaust, while he's studying mechanical engineering I'd like to be explained in less ...technical terms why I shouldn't have one. The F1's have twin exhausts, and while he explained to me why a normal car shouldn't and it would make it slower, I've kind of forgotten. I should probably mention that I want to get a mini yes I know, but I'm a girl I think that's acceptable, and I'm a small girl so again acceptable big cars and me DO not work, and the mini's are easy to scoot around the city in. Anyway , aside from that, um would it be a bad idea to have twin exhausts at all ? I want a light fast car, as fast as mini's can get, so explain to me what I would be doing wrong by doing this

[garbo]

You have to remember that a mini is an in line 4. A F1 machine is a V10! The manifold or headers come of each bank into a single pipe. Thus giving twin pipes. The headers are tuned to the right length before they converge into one achieving the right amount of pressure. Running twin exhausts on a mini would lose this 'tuning effect ' and a loss of power! Despite a terrible sound I would think! Just watch how the performance on any race car drops when pressure is lost due to a broken manifold. They are also refered to as extractors due to their ability to help suck out exhaust gasses and increase cylinder efficiency. Twin pipes on a mini would lose this effect since this sucking out effect relies on all of the cylinders to be connected on the exhaust side. But of course there is nothing to stop you running twin pipes after the point where the extracters converge into one. If it tickles your fancy?

[Ray Bell]

Or having a twin pipe out the back of the rear muffler. These can be found with one pipe in and two pipes out.

Or you can fake it...

[Christiaan]

Garbo, I believe that the M3 is a flat six with twin exhausts.

Babydoll, my understanding is that the exhausts manifold (the thingimajic that links the silencer assembly to the exhaust ports) is specificillay designed to work for a given silencer dimension. I have seen kits where you can take your exhaust and branch it into two and have two tailpipes. The disadvantage may be that when you interefere with the path that your exhaust gases travel then they are not removed from the cylinder with maximum efficiency. If you have residual exhuast in your cylinder it can affect the effeciency of combustion. (Although this is not a hard fast rule)

What I thought of doing on my Ford was making two seperate exhaust manifolds, each servicing two cylinders. That way the manifolds could be designed around an available silencer and I would get twin exhaust with optimum performance. In reality I found that this was very difficult to make work.

[Korr]

There's a difference between having twin exhaust pipes from the exhaust manifold back and having twin exhaust pipes from the catalytic convertor back (or, simply two mufflers).

The Mini has an inline 4 cylinder with a 4 into 1 exhaust manifold. I don't see any benefit to changing this arrangement.

You may opt for an exhaust system that offers twin mufflers for that sporty look and sound, and you may pick up a few horsepower as well.

The M3? I ssume you made reference to the BMW M3. It has a straight 6 cylinder engine.

[DEVO]

twin mufflers is not a problem for any type of engine... now a true twin exhaust system on anything but a 2 engine (V or Flat) bank car is not going to happen. If you want twin mufflers or twin pipes out the back on a MIni then it's just for show and not really a twin exhaust system. no harm with this setup.

this is as non technical as i can make it.

[void babydoll]

OK i get it now , the whole efficiency issue i understand that having two er that is a geniune twin exhaust wouldn't really be worth it, considering the conversion work I'm GUESSING it would take which really on a mini why bother. No harm in having a sporty look though as I'm not intending to restore the car as an original seeing as that ultimately i'm the one who's going to be driving the damn thing and the woodgrain interior thing just doesn't do it for me either. I'm thinking it's pretty acceptable to have a dual looking exhaust , if the ...new mini's can and also given the stupid example i saw today . It was a lexus - rice mobile - with HUGE coffee can style exhausts i mean stupidly huge , one on each side that being a small female i could probably crawl into. This is not the look i'm after fear not ! Thanks for contributions to my feeble knowledge .

[nicholasc]

That lexus may have been rice but I've heard it is possible to dump some mighty big stuff under the bonnet.
Those Exhausts are usually connected to 200SX's and of course WRX's here.

What year is your mini?

[void babydoll]

Trust me hun this car was nothing special, it was looks only, though naturally i cannot be sure cos i don't know the person whos car it was. I haven't a mini yet am still looking around because the most available old ones are clubmans the fronts are sooo ugly and to buy one and get the bodywork converted into a morris or a city style wouldn't be worth it. I went to a mini place with my friend who has just purchased a mini that belonged to an old woman - who was once young naturally - however its in mint original condition , the seats perfect , but old still. I found a pink mini out there but alas it was a clubman with a steering wheel and little else. Considering the colour of the thing - i'm a girl shoot me - i got excited. But then i thought....nah i have taken to a sage green colour, but it's more likely that whatever i'll get it will be getting a bare metal respray . I was thinking red - too common, maybe black, i have no idea, but pink is SO not going to happen. Apart from the fact no one would buy it, i don't want to ruin it altogether and make it a barbie car - yuck. There aren't many places in melbourne that have old ones in good condition, i'm not willing to buy a shell that's just too much work, at the same time i don't want to buy one for seven grand that i have to spend 4 or 5 on because it looks crap and hasnt been looked after. Are you a mini fan yourself Nic ?

[CdnF1Fan]

Babydoll - You might think a twin exhaust (pipe) setup looks trick on a 4 cylinder engine, and I don't doubt that a very small improvement in HP might be made using a free flow - dual pipe exhaust setup. But you must ask yourself - if you were to gain 3 to 5 HP, would the added weight of the dual pipe setup offset the gains you make in engine HP? I think not ......

CFF

[void babydoll]

I know tsk tsk my bad i'll eventually get some roller rockers and got knows whatever else i can get my hands on , foregoing to few hp really doesn't matter - this i realise - and will go with the fake look.

[AS110]

A Mini with extractors and a Cooper S muffler sounds beautifull and distinctive - all the old farts will trip over their walkers when they hear you come down the road!

[void babydoll]

I do want the sporty look as i have said, but are you saying i should get my hands on a mini cooper s muffler as in from a new one ? I guess it wouldn't look that different - well der - tell me what your suggestion would do performance wise in more detail as opposed to scaring old people - not that i'm not into that they **** me like no other citizen on earth - well except small children.

[nicholasc]

Originally posted by void babydoll
Trust me hun this car was nothing special, it was looks only, though naturally i cannot be sure cos i don't know the person whos car it was. I haven't a mini yet am still looking around because the most available old ones are clubmans the fronts are sooo ugly and to buy one and get the bodywork converted into a morris or a city style wouldn't be worth it. I went to a mini place with my friend who has just purchased a mini that belonged to an old woman - who was once young naturally - however its in mint original condition , the seats perfect , but old still. I found a pink mini out there but alas it was a clubman with a steering wheel and little else. Considering the colour of the thing - i'm a girl shoot me - i got excited. But then i thought....nah i have taken to a sage green colour, but it's more likely that whatever i'll get it will be getting a bare metal respray . I was thinking red - too common, maybe black, i have no idea, but pink is SO not going to happen. Apart from the fact no one would buy it, i don't want to ruin it altogether and make it a barbie car - yuck. There aren't many places in melbourne that have old ones in good condition, i'm not willing to buy a shell that's just too much work, at the same time i don't want to buy one for seven grand that i have to spend 4 or 5 on because it looks crap and hasnt been looked after. Are you a mini fan yourself Nic ?

Bit of a fan - I grew up in one - my mum had one and my first GF had one too - lime green.
Not enough of a fan to get a modern day one though - I've got a 206.
I'm in Melbourne too so when it's painted let us know and I'll look out for it.

nick

[void babydoll]

I like peugeots is that even how you spell it lol ? yeah anyway the ah 306's are nice but i think they're a little...conformity like - poor english i know - performance is good though from what i guess/know - more guessing than knowing ! I grew up in mini's , my aunty who i now don't see had many and i remember every time i got into the backseat i'd cut my wee lil ankles and they'd bleed or...cut or something tragic. While they're not very safe unless you do a fair bit to them which i intend to do fear not ! The new ones are not my thing they are bigger but fit less in them or something the tacho's (spelling ???) are.....stupidly oversized and bigger than the size of my head - ok exaggeration. The sound of a lime green mini is NOT compelling !

[dosco]

Originally posted by garbo
They are also refered to as extractors due to their ability to help suck out exhaust gasses and increase cylinder efficiency.

I thought this effect only applied to 2-stroke engines?

[DEVO]

void babydoll,

FYI, the Mini Cooper S (new version) has twin exhausts. Has 2 mufflers... but comes from 1 exhaust pipe (after the exhaust headers, don't know if it 4->2->1 or 4->1). So the "look" you are looking for comes in the cooper S. There are aftermarket exhaust for the cooper S that also take advantage of the 2 muffler slots.

My S2000 has twin exhaust but has single bank of cylinders. The twin exhaust gives a nice engine note. Even though a straight single exhaust could add additional power. But from a looks/sound perspective the twin is nice.

[VAR1016]

Originally posted by void babydoll
I know tsk tsk my bad i'll eventually get some roller rockers and got knows whatever else i can get my hands on , foregoing to few hp really doesn't matter - this i realise - and will go with the fake look.

Babydoll! roller rockers?

Your slip's showing

PdeRL

[void babydoll]

lmao yeah yeah i think what you think er i think is that i thought that's all was required to give the car some go or something if that's what you're mocking me for - don't, i know all cars have them but i was getting into something specific or at least hoping for more engine specific info about the cam etc - give me time i'll annoy you all some more with painful qestions. Man i know its roller tip rockers i wasnt aware i had to spell everything out for you ! : keep your ugly green man away !

[VAR1016]

Originally posted by void babydoll
lmao yeah yeah i think what you think er i think is that i thought that's all was required to give the car some go or something if that's what you're mocking me for - don't, i know all cars have them but i was getting into something specific or at least hoping for more engine specific info about the cam etc - give me time i'll annoy you all some more with painful qestions. Man i know its roller tip rockers i wasnt aware i had to spell everything out for you ! : keep your ugly green man away !

Well what I meant wasthat on the one hand your are asking about twin exhausts in an apparently naive fashion - and then just like that you chuck in roller rockers - which are a long way away from twin exhausts, go-faster stripes etc.

As for the green man? I am in clouds of smoke as I write this - in the words of the old song: "Been smokin' 'em all my life and I ain't dead yet."

PdeRL

[void babydoll]

ah ha sorry i had a moment of clarity . Well not really , i'll remember that anything outside of the topic MUST be placed in another post , give me time to adjust or ....get with the programme. :

[VAR1016]

Originally posted by void babydoll
ah ha sorry i had a moment of clarity . Well not really , i'll remember that anything outside of the topic MUST be placed in another post , give me time to adjust or ....get with the programme. :

Er, this is getting increasingly surreal! (actually surreality is something that I quite enjoy)

What I meant to say was that knowledge of such exotic components as roller rockers (wish I had them for my Lancia Fulvia) are a long way from decorative exhaust systems!

PdeRL

[Ray Bell]

I think there is some confusion and misinformation here...

First of all, let's clarify (this is the clarification, I'm not asking for clarification, it's been done before but ignored by some) that this is the type of Mini void babydoll is discussing...



Not a modern one built by BMW... and probably an Australian version with wind up windows.

Now, about this little question, so far unaddressed:

Originally asked by dosco
I thought this effect only applied to 2-stroke engines?

Not so... using the inertia of the flow from one cylinder to help draw the gas from another is a well recognised part of 4-stroke tuning. But on a Mini it would require a total exhaust system replacement to work properly.

And this little point...

Originally suggested by CdnF1Fan
Babydoll - You might think a twin exhaust (pipe) setup looks trick on a 4 cylinder engine, and I don't doubt that a very small improvement in HP might be made using a free flow - dual pipe exhaust setup. But you must ask yourself - if you were to gain 3 to 5 HP, would the added weight of the dual pipe setup offset the gains you make in engine HP? I think not ......

A few kgs of weight makes absolutely zero difference to running costs...

Apart from that, the reason you get the power is because you make the engine more efficient, so driven the same way it will use less fuel. But there will only be a gain if there's a proper extractor system.

I don't think you can get roller rockers for a Mini... nor roller cam followers...

[stuartbrs]

Ive seen a REAL Mini down here in Tassie with twin exhausts...it can be done, no idea as to the performance hit/gain though.

And as Ray says, you can always fake it,get the look without the hassle, no one would really know anyway.

[Greg Locock]

"But you must ask yourself - if you were to gain 3 to 5 HP, would the added weight of the dual pipe... "

Whoever wrote that originally has never played with a Min. Taking that as 4 hp,a 10% horsepower boost from diddling the exhaust only? Dream on.

I used to have a Min. One of the few cars I've really liked, as opposed to used.

[Leo]

Originally posted by DEVO
twin mufflers is not a problem for any type of engine... now a true twin exhaust system on anything but a 2 engine (V or Flat) bank car is not going to happen.

Well, how about this nice 4-in-2 example.. (oops, it's not a car ;) )


Click to enlarge

[VAR1016]

The only example I can think of of a genuine twin-exhaust four cylinder car is the famous Bertone Lancia Stratos prototype, known as the "tart-catcher" of 1970.

This was fitted with the engine, transmission etc. from a 1600 Fulvia (4-cyl) and strangely had a dual exhaust system. It would not have worked very well....

I have yet to find out if it ever actually worked; the car definitely still exists and was photographed (on a trailer sadly) quite recently in Italy.

PdeRL

[Yorgos]

Originally posted by VAR1016
The only example I can think of of a genuine twin-exhaust four cylinder car is the famous Bertone Lancia Stratos prototype, known as the "tart-catcher" of 1970.

This was fitted with the engine, transmission etc. from a 1600 Fulvia (4-cyl) and strangely had a dual exhaust system. It would not have worked very well....

I have yet to find out if it ever actually worked; the car definitely still exists and was photographed (on a trailer sadly) quite recently in Italy.

PdeRL

From all sorts of Minis and dolls to the original Stratos...in fact a surrealist discussion.
The first Stratos (that wedge shaped...er..contraption) did actually work. Quattroruote took it for a drive in the center of Milan sometime in 1971. I have the issue somewhere, if/when I find it I will scan the article, complete with photos from the inside looking out.

Cheers
Yorgos

[VAR1016]

Originally posted by Yorgos


From all sorts of Minis and dolls to the original Stratos...in fact a surrealist discussion.
The first Stratos (that wedge shaped...er..contraption) did actually work. Quattroruote took it for a drive in the center of Milan sometime in 1971. I have the issue somewhere, if/when I find it I will scan the article, complete with photos from the inside looking out.

Cheers
Yorgos

Dear Yorgos,

As a a hopeless Fulvia (and indeed Lancia addict) I am very keen indeed to see this.

Thanks

PdeRL

[Ray Bell]

Is it possible that SAAB tied a dual exhaust on their V4 model at some time?

[VAR1016]

Originally posted by Ray Bell
Is it possible that SAAB tied a dual exhaust on their V4 model at some time?

I suppose that that may be possible; it was a 90 degree engine wasn't it?

Of course the most popular one would be the VW Beetle - not renowned for its efficiency or for a mellifluous exhaust note!

PdeRL

[Ray Bell]

Wasn't the SAAB engine one they shared with Transit vans?

Not sure about the included angle of the vee, Ford had a few different engines at that time, some from England and some from Cologne... which leads me to remember another car that might well have had dual exhausts on a four... the original Mustang concept car... if only for the visual impact.

[VAR1016]

Originally posted by Ray Bell
Wasn't the SAAB engine one they shared with Transit vans?

Not sure about the included angle of the vee, Ford had a few different engines at that time, some from England and some from Cologne... which leads me to remember another car that might well have had dual exhausts on a four... the original Mustang concept car... if only for the visual impact.

Yes the 2-litre V-4 was used in Transits; as far as I recall it first appeared in that horror the Corsair GT about 1966 - the only good thing about that car was the "Bullet" gearbox that evrybody wanted.

Last time I saw a Ford V-4 I was amazed that SAAB managed to get any power at all from it; horrible thing. I have been told that SAAB built prototypes using the Lancia Fulvia V-4 (a proper engine) but that that idea was killed by the cost.

I suppose that a V-4 was essential since the car was based on the old 3-cylinder two-stroke car.

PdeRL

[Ray Bell]

I don't think it was anything like two litres either... in fact it was 1498cc... the Mustang prototype had a Taunus 12M engine of 1.9 litres apparently.

[VAR1016]

Originally posted by Ray Bell
I don't think it was anything like two litres either... in fact it was 1498cc... the Mustang prototype had a Taunus 12M engine of 1.9 litres apparently.

I can only recall the Corsair 2000GT as the first user of the V4. Certainly the Transit had a 2-litre engine.

I have now a vague recollection of a 1700cc version though.

And to think I used to have a memory!

PdeRL

[Ray Bell]

So what pommie Ford had the 1500? I'm sure SAAB didn't get a total orphan...

Oh, here's a photo of the SAAB Sonett with the twin exhausts we've been looking for!



And it was a pommie engine, not a German one. Was there a base Corsair with the 1500? Not according to the Motorbase website... but like I said, it's hard to imagine SAAB getting an orphan engine.

Am I correct in recalling that the pommie Vees were 90 degrees and the German Ford ones somewhat different?

[VAR1016]

Originally posted by Ray Bell
So what pommie Ford had the 1500? I'm sure SAAB didn't get a total orphan...

Oh, here's a photo of the SAAB Sonett with the twin exhausts we've been looking for!



And it was a pommie engine, not a German one. Was there a base Corsair with the 1500? Not according to the Motorbase website... but like I said, it's hard to imagine SAAB getting an orphan engine.

Am I correct in recalling that the pommie Vees were 90 degrees and the German Ford ones somewhat different?

Blimey Ray,

Now you're asking.

I really cannot remember . The Ford V4 was a dreadful thing anyway and I was never interested in it; I felt sorry for the people at SAAB being stuck with it.
I would have loved to have seen what their development people could have done with the Lancia V4

PdeRL

[Ray Bell]

Well, if nothing else we've found an example of twin exhausts on a 4-cyl engine....

And that without looking at a single Formula Vee.

[se7en_24]

A addition:

If you're talking about the old mini the cylinder head only has 3 exhaust outlets.

[SeanValen]

Originally posted by se7en_24
A addition:

If you're talking about the old mini the cylinder head only has 3 exhaust outlets.

Heard of the clutter twin nosel exhaust ideas, it boosts efficiency by a ci ci vin menchaism chip located near the exit of the exhaust, designs are very skecthy right now, but you heard it here first.

[VAR1016]

Originally posted by SeanValen


a ci ci vin menchaism chip located near the exist of the exhaust,

A what?



PdeRL

[Ray Bell]

Originally posted by se7en_24
If you're talking about the old Mini the cylinder head only has 3 exhaust outlets.

Yes, the centre two are siamesed and there's no way of separating them with the original head... there are crossflow heads, but that's not an issue here.

I thought everybody realised that?

[se7en_24]

Originally posted by Ray Bell
Yes, the centre two are siamesed and there's no way of separating them with the original head... there are crossflow heads, but that's not an issue here.

I thought everybody realised that?

It wasn't mentioned in the thread before as far as I noticed, and with regards to having 'twin exhausts' it is quite an important detail Ray ;)

I only mentioned it because it is fairly unusual and very relevant to the topic. But carry on talking about windup windows if you like

[SeanValen]

Originally posted by VAR1016


A what?



PdeRL

Futuristic chip in design, I'll tell you more in the future when more info is revealed.

[Ray Bell]

Originally posted by se7en_24
It wasn't mentioned in the thread before as far as I noticed, and with regards to having 'twin exhausts' it is quite an important detail Ray

I agree, perhaps it should have been spelled out earlier.