Janspeed manifolds - Worth the money?

[dave23572]

Subject says it all really.
Are the Janspeed manifolds for the 180 worth the money?

1. Is it a good and noticeable performance increase?
2. Is the increase all through the rev range or only in certain ranges?
3. Does it reduce torque in any rev ranges (compared to standard manifolds)?
4. Would the manifolds give a good performance increase when used with an otherwise standard exhaust system and CAT? or does it really need a sports cat etc?

Dave

[Drew]

yes.

http://i16.photobucket.com/albums/b5/Roverdose/RollRd10.jpg

i cant say how much you would get on a std exhaust as i already had a decat and full system, but the gains are there to see.

Drew

[dave23572]

So those gains were with the manifold replacement alone?

And what did the gains feel like when driving?
Very noticable?

Dave


yes.


i cant say how much you would get on a std exhaust as i already had a decat and full system, but the gains are there to see.

Drew

[redzed]

Throw a decat with it and it sounds amazing, very noticable gains and transforms the sound of the car

[dave23572]

Throw a decat with it and it sounds amazing, very noticable gains and transforms the sound of the car


But presumably then the car is not legal?
Don't you have to keep re-fitting a temporary cat for the MOT?

[Fred68]

From what I seen, the JS manifold is well short of optimum. It makes more power than the original manifold. Not because the JS is particularly good, more the standard manifold is particularly bad.
The primaries are way to short for decent torque at the kind of RPMs the KV6 can muster.
The finish on the standard manifold is dire. Just look at this collector. The JS has to be be than the standard manifold.

[dave23572]

From what I seen, the JS manifold is well short of optimum. It makes more power than the original manifold. Not because the JS is particularly good, more the standard manifold is particularly bad.
The primaries are way to short for decent torque at the kind of RPMs the KV6 can muster.
The finish on the standard manifold is dire. Just look at this collector. The JS has to be be than the standard manifold.



That really is disappointing to see.
Looks like with some more effort they could have designed something way better.

But I guess in the absense of anything better, the JS manifold may still be worth considering, given that it's still a good gain over the standard one?

Dave

[Fred68]

That really is disappointing to see.
Looks like with some more effort they could have designed something way better.

But I guess in the absense of anything better, the JS manifold may still be worth considering, given that it's still a good gain over the standard one?

Dave

The only other way is making a good manifold your self.
The primaries want to match the ID of the exhaust ports and be as close to 30" long as possible before the collectors. The bends need be smooth and mandrel formed. The collectors need to be 1 over 2 and correctly welded so as not to impede gas flow. The secondaries need to be around 2" ID and be approximately half the length of the primaries. These then need to collect into a 2 1/2 free flowing system.
It's possible to build up a much better set of manifolds than the JS version.

[dave23572]

The only other way is making a good manifold your self.
The primaries want to match the ID of the exhaust ports and be as close to 30" long as possible before the collectors. The bends need be smooth and mandrel formed. The collectors need to be 1 over 2 and correctly welded so as not to impede gas flow. The secondaries need to be around 2" ID and be approximately half the length of the primaries. These then need to collect into a 2 1/2 free flowing system.
It's possible to build up a much better set of manifolds than the JS version.

If only I were able to make such a thing!

It's a shame there was never a performance replacement for the entire plenum (apart from the Sprintex supercharger plenum).
The normal plenum really doesn't look like it would flow well. And we all know how well designed and reliable the VIS system is don't we?

Theoretically, I expect with the exhaust manifold you described and an optimal plenum, the KV6 would have performed much better.

[petet16]

The result of a limited development budget for the zs, and the need to package it to fit in the front of the 45/zs.

[Mark S]

If only I were able to make such a thing!

It's a shame there was never a performance replacement for the entire plenum (apart from the Sprintex supercharger plenum).
The normal plenum really doesn't look like it would flow well. And we all know how well designed and reliable the VIS system is don't we?

Theoretically, I expect with the exhaust manifold you described and an optimal plenum, the KV6 would have performed much better.

very true, if you sorted the plenum and exhaust, dropped in some cams you should see 200lb/ft and around 220-230bhp.

[Fred68]

With a decent set of manifolds and well designed exhaust system, the standard ZS180 would be a ZS195 or there abouts. Include a well flowing air filter housing and the std 2.5 V6 will make 200 bhp.
We don't really know how much is gained or lost by the plenum as not many have replaced them. I know of a couple of Rover 800 KV6 twin TB inlets. As to the power of those, I'm not sure.
Looking inside the plenum, it's a wonder the engine makes what it does.
It's almost like MG Rover built in HP restrictions. As to why, who knows, but I suspect it was to do with budgets.
Don't forget that in the right hands, the works 2 Liter KV6 made near 300 Bhp!!

[top_man_eldo]

With a decent set of manifolds and well designed exhaust system, the standard ZS180 would be a ZS195 or there abouts. Include a well flowing air filter housing and the std 2.5 V6 will make 200 bhp.
We don't really know how much is gained or lost by the plenum as not many have replaced them. I know of a couple of Rover 800 KV6 twin TB inlets. As to the power of those, I'm not sure.
Looking inside the plenum, it's a wonder the engine makes what it does.
It's almost like MG Rover built in HP restrictions. As to why, who knows, but I suspect it was to do with budgets.
Don't forget that in the right hands, the works 2 Liter KV6 made near 300 Bhp!!

Fred you sound like you know what you're talking about, why don't you make up a batch of these exhaust manifolds for the 180?!

I'll be the first to put my name down!:shifty:

[Mark S]

I know of only one person who had custom mani's made (that were of a tuned length - forget haywood and scott) and they cost more than most people here would want to spend on a ZS!!! (although they are very good) Small quantities are still expensive until you get the numbers where its worth making a jig to produce them...unless you can find someone who would do it as a labour of love...???

[petet16]

Did Tony Law make some as well ?.

[top_man_eldo]

Did Tony Law make some as well ?.

I was talking to a fella from Ipswich way on MGR forums a while ago and he was going to have a go at making some for the KV6, not sure whether he eventually got round to it.

[Fred68]

Fred you sound like you know what you're talking about, why don't you make up a batch of these exhaust manifolds for the 180?!

I'll be the first to put my name down!:shifty:

My knowledge of what works and what doesn't comes from building some rather interesting engines back in the 80's. Then things were limited by head flow capacity.
With modern multi valve heads, it's the bolt on bits that limit power from the factory instead. The KV6 seems to be worse than other engine in this respect. It's almost like MR Rover were worried about warranty claims, deliberately down rating the engine.

I did loads of mods to my first ZS180 some time in 2003. I did use the JS manifold and custom made system to match. I was never happy with the manifolds though.
It wasn't until I did some number crunching that I realised that the primaries need to be long.
With the KV6, it's all about optimisation and knowing what does and doesn't work.

The problem with making up manifolds and systems now would be sales volume. There just isn't the demand for them to make it a viable proposition.
This would leave you, the owner to find an exhaust fabricator willing to make a 1 off.
The JS manifold will work for most owners needs and it is miles better then the factory manifold. But it's far from optimal.
This was discussed at length some years ago on XPF.
I don't have a ZS180 any more.
I do still run a KV6, sadly it's coupled to an auto box in a Freelander!!

[petet16]

The sales volume issue is a valid point, a while back I spoke with JS about making up some duel outlet systems for the 180, they would only make them in batches of 5, which I would have fronted the money for IF I thought there was any chance of selling the other four on, as it turned out I was pointed in the direction of a used system on ebay, so the JS idea never went anywhere.

[Skillen]

Just thought I would see how much a mandrel bending machine would be thought I may as well give it a blast by myself and what better way to start to learn to weld.
Well I gave up at the mandrel bender part. £15k for a pneumatic one. Nearly £600 for a manual one.
Ha. I'll stick with my janspeeds.

[Fred68]

Thankfully there are lots of ready formed bends available for the home constructor. These would need welding together to make pretty much whatever you need. ;)

[talkingcars]

As part of my maestro project I'm planning to do a night school course in welding, once the body's sorted I'm fancing knocking togeather a manifold............

[dave23572]

Just a thought.

If anyone knows a firm that is capable of making some custom manifolds to meet Fred68's specifications, I was wondering, if we got enough people together willing to buy one, then a batch could be made which would get the unit cost down to something possibly affordable.

I don't know anyone, but even if there was, I guess they would need some time to design and develop it, plus also I guess the designer/manufacturer would need a loan ZS180 car to develop around and do trial fitments and testing etc.

I guess this idea is pie in the sky...

[Fred68]

Manifold and exhaust design is extremely complex. In reality, to get optimum torque from any engine requires a custom designed system. A optimised manifold can help the cylinders fill with the next air charge. Now obviously anyone building systems for open market would need to compromise the system. Manifold primary and secondary length is dictated by many factors. The size of the pipes is very important. Too larger and gas speed will be slow. Too small and although gas speed will be high, back pressure will increase.
Primary length is dictated by many factors. Things like bore diameter and stroke, rod length and valve open/ overlap period are all important. To make things more complex. The optimum primary length is only beneficial at certain points in the rev range. The trick is to get benefits in key points in the rev range at the same time, not causing massive losses elsewhere in the rev range.
This is where secondary length helps. The secondaries can be optimised to lift low points in the rev range.
If all the science is removed from the design. The very best option is remove anything in the manifold and system that causes a restriction to gas flow.
This is why manifolds like the JS manifold work. It's not adding power to the engine, but it doesn't rob to much ether.

Years ago, I made several manifolds with slightly different primary lengths. The theory was to spread a smaller power increase over a wider rev range. It worked too but I found with this method, carburettor calibration almost impossible. Mostly because anything done to the exhaust is reflected in the intake.

[dave23572]

Very interesting and a shame such a manifold was never developed.

[top_man_eldo]

Interesting reading, the fella I was talking to who was designing and building his own manifolds for the 180 was "2bellys" on .org forums. I'll give him a PM to see how he's getting on as it was around 8 months ago that he mentioned this.

[Fred68]

Very interesting and a shame such a manifold was never developed.

The only way such a manifold would come to fruition would be if sold as a complete kit. This would come with heads, cams, ECU, air filter/cold intake and the manifolds and system. Going to this extreme would add lots of power over standard but the cost to many would be prohibitive.
As a DIY build, a well made manifold with longer primaries would be a viable alternative to the JS manifold.

[easytime]

'It's not adding power to the engine, but it doesn't rob to much ether.'

What you have just said is that the JS rob power?

[Mark S]

a diy build mani would not come cheap, if you count up the bends in a custom set of mani's which have 24" primaries (and you are talking about 30" here!!!) on a kv6, and multiply that number by £15, which is the typical cost for a mandrel bent piece of steel, perhaps more for stainless??? you will easily exceed the cost of the janspeeds, this is before you've had the header plates laser cut and attempted welding it together!!!
To add to this, you will be ordering bends which are not off the shelf - as in, not a 15, 30, 45 degree bend etc.

[Fred68]

'It's not adding power to the engine, but it doesn't rob to much ether.'

What you have just said is that the JS rob power?
Pretty much anything that is bolted to the exhaust or inlet ports of an engine will loose torque.
A correctly designed manifold will or can cause a vacuum in the exhaust port. This vacuum will draw extra air into the cylinder via inlet valve. This does add torque over and above that, that is generated by open ports.
This extraction only works for a set design of manifold. Any other type of compromised designed does in fact loose torque, when compared to open ports.
The JS manifold is much better in terms of flow over the standard manifold. This is why there is a torque gain.
It's not the last word in extraction manifolds for the KV6 though.

[redzed]

heres a very bad quality vid of the sound of my zs with janspeeds. http://s1363.photobucket.com/user/ian461/media/janspeedmanis_zpsbbd250d5.mp4.html

all i have is a induction kit and janspeeds (not been remapped and is on standard cams) and its rolling roaded at 175bhp @ the wheels (190-210bhp at fly depending on how its guessed ;-) ), which is not a bad amount of power

[easytime]

Pretty much anything that is bolted to the exhaust or inlet ports of an engine will loose torque.
A correctly designed manifold will or can cause a vacuum in the exhaust port. This vacuum will draw extra air into the cylinder via inlet valve. This does add torque over and above that, that is generated by open ports.
This extraction only works for a set design of manifold. Any other type of compromised designed does in fact loose torque, when compared to open ports.
The JS manifold is much better in terms of flow over the standard manifold. This is why there is a torque gain.
It's not the last word in extraction manifolds for the KV6 though.

Right ok, so I should have a net improvement over the MGR units with my JS manis?

[easytime]

heres a very bad quality vid of the sound of my zs with janspeeds. http://s1363.photobucket.com/user/ian461/media/janspeedmanis_zpsbbd250d5.mp4.html

all i have is a induction kit and janspeeds (not been remapped and is on standard cams) and its rolling roaded at 175bhp @ the wheels (190-210bhp at fly depending on how its guessed ;-) ), which is not a bad amount of power

I have an iTg, JS manis and cat back system twin exit, would love to know how much that makes. I did have a decat but she felt really flat with it so the cat went back on.

[redzed]

Right ok, so I should have a net improvement over the MGR units with my JS manis?

Definately

[Lukeus101]

Id love to see what the full janspeed on ours has done

[easytime]

I saw a plot for iTg and cat back at 196Bhp, so I will guess at 205 with manifolds too.

[Maxfly]

Mine, with manifolds, sports cat and stainless catback has consistently made around 203bhp. What the manifolds seemed to add to on this car is the torque and I would need to pull out the last RR printout to see what it ended up at.:)

[easytime]

Mine, with manifolds, sports cat and stainless catback has consistently made around 203bhp. What the manifolds seemed to add to on this car is the torque and I would need to pull out the last RR printout to see what it ended up at.:)

Sooo, not a bad guess then, There are 2 mods where I could feel the difference. The first was the iTg Maxogen, that really made a huge difference, they claim 12-14 gain and I fully believe that, the second was the manifolds but have no numbers for that. They say you cant feel anything less than 5% gain so with the iTg thats at least 9.6bhp. Total that and you are a hairs width away from 203.

[Maxfly]

Aye very close:) forgot to say it is a Bmc-CDA I have for induction:)

[Fred68]

A good cold air feed is so important. The KV6 seems really sensitive to it. The number of 180's that I've seen with a small cone filter slapped onto the standard intake pipe is untrue. I wonder how the owners don't notice the lack of gain.
I did an experiment with my V6 Freelander last year.
The standard filter housing is dreadful as it sits on top of the engine. This causes it to warm the intake charge considerably, I've recorded 55°C!! I thought I'd try a large cone filter instead.
Not wanting to waste dyno time, I just rode my own dyno (the car).
I did a few 1/4 mile runs with both filters fitted.
The result was pretty much what I expected.
No difference between the two. Both filters give the same times.
I'm currently working on a nice cold are feed for my KV6 engine as they are proved to work well.

[easytime]

A good cold air feed is so important. The KV6 seems really sensitive to it. The number of 180's that I've seen with a small cone filter slapped onto the standard intake pipe is untrue. I wonder how the owners don't notice the lack of gain.
I did an experiment with my V6 Freelander last year.
The standard filter housing is dreadful as it sits on top of the engine. This causes it to warm the intake charge considerably, I've recorded 55°C!! I thought I'd try a large cone filter instead.
Not wanting to waste dyno time, I just rode my own dyno (the car).
I did a few 1/4 mile runs with both filters fitted.
The result was pretty much what I expected.
No difference between the two. Both filters give the same times.
I'm currently working on a nice cold are feed for my KV6 engine as they are proved to work well.

Years ago I stuck a K&N cone right onto the TB with Duck tape, took her out and was blown away with the noise, it was sweet. What caused me to subsequently rip the cone off was the total loss, yes loss of power. I was amazed after that to see people blowing hard about open cones in 180's, you really need to be brain dead not to notice the missing 40BHP with a cone. In-fact you deserve a cone if you like a cone.

[talkingcars]

Even an enclosed cone sucking heated air in the engine bay will lose you power.

[Fred68]

Years ago I stuck a K&N cone right onto the TB with Duck tape, took her out and was blown away with the noise, it was sweet. What caused me to subsequently rip the cone off was the total loss, yes loss of power. I was amazed after that to see people blowing hard about open cones in 180's, you really need to be brain dead not to notice the missing 40BHP with a cone. In-fact you deserve a cone if you like a cone.

Absolutely. If the standard filter housing could be insulated from the heat of the rad. It would work much better than standard. The 180's standard filter is nice and large, so should flow well enough. Provided there is plenty of cool air available, power should improve.
Did you know that most pleated paper filters will flow around 4 cubic feet per minute, per square inch of area. An engine requires 2.2 cfpm of air per Bhp. So a 200 Bhp engine requires a filter that can provide 440 cfpm of cool filtered air.
If you work out the area of the standard paper filter in the ZS180, then multiply by 4, you will see that it will flow enough for the engine. Obviously this is when the filter is new. Once it's beginning to clog with debris, it's capacity drops of sharply.
I reckon that K&N cotton filters are hard to beat. They flow as well as new paper and don't clog to fast ether. I've found that foam filters that flow lots of air, don't actually filter that well. Foam that filters well doesn't flow well, this is a bit pointless really.
So a good set up would have a good size filter picking up cool air. Much like the inner wing set up, most in the know favour.

[easytime]

Absolutely. If the standard filter housing could be insulated from the heat of the rad. It would work much better than standard. The 180's standard filter is nice and large, so should flow well enough. Provided there is plenty of cool air available, power should improve.
Did you know that most pleated paper filters will flow around 4 cubic feet per minute, per square inch of area. An engine requires 2.2 cfpm of air per Bhp. So a 200 Bhp engine requires a filter that can provide 440 cfpm of cool filtered air.
If you work out the area of the standard paper filter in the ZS180, then multiply by 4, you will see that it will flow enough for the engine. Obviously this is when the filter is new. Once it's beginning to clog with debris, it's capacity drops of sharply.
I reckon that K&N cotton filters are hard to beat. They flow as well as new paper and don't clog to fast ether. I've found that foam filters that flow lots of air, don't actually filter that well. Foam that filters well doesn't flow well, this is a bit pointless really.
So a good set up would have a good size filter picking up cool air. Much like the inner wing set up, most in the know favour.

Standard setup flows well? Have you seen the diameter of the air inlet on the bottom of the filter box? It is about 1 inch or 30-35mm feeding a 100mm throttle body. Yes the filter could flow that much air IF it could be fed that much air which it can't, done on purpose by MGR to slow down the ZS in speed and BHP to boost the ZT190 figures. Ever wonder why the zt was 190 and the ZS was 180? All key engine parts have the same numbers except the induction and exhaust manifolds.
If you could get the 35mm inlet enlarged you would feel a big difference, Maxogen is worth a good 12bhp just by getting the right amount of air to the engine at ambient air temps.

[Fred68]

Standard setup flows well? Have you seen the diameter of the air inlet on the bottom of the filter box? It is about 1 inch or 30-35mm feeding a 100mm throttle body. Yes the filter could flow that much air IF it could be fed that much air which it can't, done on purpose by MGR to slow down the ZS in speed and BHP to boost the ZT190 figures. Ever wonder why the zt was 190 and the ZS was 180? All key engine parts have the same numbers except the induction and exhaust manifolds.
If you could get the 35mm inlet enlarged you would feel a big difference, Maxogen is worth a good 12bhp just by getting the right amount of air to the engine at ambient air temps.

I'd forgotten about the bottom entry, it's a long time since I've seen a standard 180 filter box. That D shaped hole has a larger area than the butterfly. Did you know throttle butterfly is only 55mm across?

The 190 engine has many differences to the 180. The inlet cam is different. It has a couple of degrees extra open time and it's been advanced 4 degrees too iirc.
The ECU mapping is slightly different too. Air filter is different as is the exhaust system. Otherwise the engines are the same.

[talkingcars]

done on purpose by MGR to slow down the ZS in speed and BHP to boost the ZT190 figures. Ever wonder why the zt was 190 and the ZS was 180? All key engine parts have the same numbers except the induction and exhaust manifolds.

Not quite, the KV6 induction was originally designed for the 2.0 auto in the Rover 45 to run against the small Jags.

The ZT auto KV6 is also 180bhp and there are differences in valve timing between the 2 models.

[easytime]

I'd forgotten about the bottom entry, it's a long time since I've seen a standard 180 filter box. That D shaped hole has a larger area than the butterfly. Did you know throttle butterfly is only 55mm across?

The 190 engine has many differences to the 180. The inlet cam is different. It has a couple of degrees extra open time and it's been advanced 4 degrees too iirc.
The ECU mapping is slightly different too. Air filter is different as is the exhaust system. Otherwise the engines are the same.

The D shape hole is the same size as a 50p, thats much smaller than the butterfly.

[dave23572]

This thread that I started has been very interesting, lots of good posts, thanks guys.

I'm certainly now very tempted to go for a Janspeed manifold and sports cat, to go with my (already fitted) ITG Maxogen.

I was a little surprised with some of the power gain figures banded about though, but actually I hope they are true. 12BHP for the ITG seems on the high side as I didn't notice a huge difference, but then again, I'm not a dyno.

So if these figures are to be believed, a ZS180 (starting at 175BHP) with an ITG Maxogen, JS manifolds and sports cat, should be pushing out 190 to around 200BHP?

One thing I have noticed, even with the ITG maxogen cold air feed, the KV6 is still very sensitive to air temperature. Producing a lot more power in cold air than on a hot day.


Slightly off topic
While I'm very tempted to go for the power mods (above), before I do those, I'd really like to improve the ZS steering to make it a lot more responsive/aggressive. I've done a lot of research on this and it seems to be an area hard to improve.

I've driven another member's 180 back-back with mine (someone that was very happy with his steering/handling) to see if there was any difference, it was exactly the same. So there's nothing wrong with my car, I guess my driving style / handling taste is different to most. I like a very responsive front end with a very quick "turn in", needing relatively less steering wheel input for any given corner.

I tested a 2010 CTR(FN2) and the steering was just what I'm looking for, but while I have flirted with the idea of just getting a CTR(FN2), I'd rather stick with the ZS and do some mods. It will actually be a cheaper overall route to a better car.

It sounds like the steering issue is related to the overall steering wheel to turning wheels ratio. I've looked into a quicker steering rack but there aren't any (that I've found anyway, Quaife certainly don't do any).

I also learned that lock-lock turns of the steering wheel isn't a good comparison between cars (such as the ZS180 and CTR), because the maximum steering lock may be different as well as other factors. I suspect the ZS has a relatively limited max steering lock, perhaps because of arch clearances or to protect the CV joints. The ZS180 has 2.5 turns lock-lock, a CTR(FN2) is 2.3. That's not enough difference to explain how much sharper the CTR steering is over the ZS. I suspect the CTR has a faster overall ratio because it may have a better max lock angle, and possibly other factors in the suspension geometry giving it this property. It may also be a shorter wheelbase. It definitely has lower profile tyres, could it be that?

It's such a shame (for me at least) that this seems to be an area that can't be improved in the ZS. It seems most owners are quite happy with their steering response and rate it highly, but different drivers have different tastes/preferences. Maybe it's because I've done a bit of karting in my time.

A quick-rack (if it existed) would be a way to go, but we would need to get the turns lock-lock to probably under 2.

Dave

[talkingcars]

Owners of 45's, 400's and civics look to the 180 for quicker racks.
Owners of 180's fit MGF/TF steering wheels for smaller wheels.

The only "improvement" you might make is increasing camber and toe-in.

You could increase feed back by disconnecting the power steering.

What is a CTR(FN2)?

[Fred68]

The KV6 is very sensitive to intake temps. The colder the better.
The ZS has one of the best steering racks available. All the Civic boy's want them.
At 2.5 turns, that's about as little as you need on a road car. Any less and you will be doing a slalom as you drive straight.
It's a personal thing but for me, the ZS rack is fast enough.

[dave23572]

Yes it seems most ZS owners are happy with their steering.
I was until I drove a CTR(FN2)

The CTR(FN2) is the 2006-2011 Honda Civic Type-R, code named FN2.
I tested it to see what a good more modern FWD car would steer like, and I was very impressed. Unfortunately the car is not as practical as a ZS saloon so not really an option for me, hence why I'm looking at mods for the ZS instead.

[talkingcars]

The KV6 is very sensitive to intake temps. The colder the better.

Agreed, I'll post my findings with O/E and BMC CDA induction.

[petet16]

The Civic may have speed sensitive steering which may be giving the difference in feel that you're looking for.
Possibly using a different sized pulley on the pas pump might give the desired effect.

[dave23572]

One final question about the Janspeed manifolds and sports cat:-

If you fitted these to a 180, would it likely make the fuel economy better or worse?

[petet16]

Worse without a doubt :D

[talkingcars]

The old argument that if you drive at the same speed you will be using less power and therefore less fuel should apply..............

[petet16]

The old argument that if you drive at the same speed you will be using less power and therefore less fuel should apply..............

It should James, but you just know it won't.

[easytime]

Honestly i did not notice any difference to fuel consumption, when bog standard she got about 230 miles to a tank, and I am still getting that 11 years and lots of mods later.

[MG ZS STE]

Honestly i did not notice any difference to fuel consumption, when bog standard she got about 230 miles to a tank, and I am still getting that 11 years and lots of mods later.

Should be getting about 100 more than that. Unless your driving it very hard everywhere you go that is.

[dave23572]

My theory was that if the car was faster, you'd be more tempted to drive it fast more often, hence worse MPG.

But if driven normally, standard vs a KV6 with JS manifolds and sports cat, would the economy be different.

ie, the engine wouldn't have to work as hard so would it be more efficient?
Or on the other hand maybe if it's making more power, it's using more fuel.

I guess without hard data, you'd just have to take a punt.

[talkingcars]

Should be getting about 100 more than that. Unless your driving it very hard everywhere you go that is.

I'm lucky to get 220 with my regular commute.

[MG ZS STE]

The only time I've seen mileage that low was when I've had a faulty precat lambda.

[talkingcars]

Basically 10 miles each way, national speed limit virtually all the way, dual carriageway for 95% but broken up by 12 roundabouts and a set of lights - fun but no good for economy.

On the other hand I have achieved 400 miles on a tank so I know it is possible on a long run.

[Maxfly]

I'm get about the same as James, 12min drive to work so car barely gets warm and the majority of it is 30-50 zones so poor mpg to be expected....part of the reason I now bike to work and only take car if I have to plus it's only 3mins more cycling.

Although when it was a 70 mile round trip for work I would easy pass 300miles but that was the previous zs's so not a direct comparison I suppose..

[Fred68]

I'm lucky to get 220 with my regular commute.

I get more than that out of my V6 Freelander!! And way more out of my 180. Do you have a heavy right foot?

[Deckz]

I worked out mine at 32mpgs

[easytime]

I live 1.8 miles from work, she is not even warm when I knock her off at work. Also there are only 2 motorways in N. Ireland! And none of them near me!

[talkingcars]

I get more than that out of my V6 Freelander!! And way more out of my 180. Do you have a heavy right foot?

As per post 62.

[dave23572]

I average 29.5 since I bought my ZS in 2006

[talkingcars]

vvvvv

[Fred68]

As per post 62.

There are lots of reasons for low mpg.
Lots of roundabouts is obviously 1 of them.
My daily commute is a mix of winding B roads with a 2 mile blast of duel carriageway. My 180 averaged 28mpg on the commute.
My ZS replacement a V6 Freelander does bang on 20mpg on the same route. It uses considerably more fuel than the ZS even though it's powered by the same engine. The Freelander is coupled to an auto box and weighs some 400 Kg's more than my old ZS180. Thus affecting the fuel consumption some what.

As for the breathing mods affecting fuel efficiency. In theory anything that helps the engine breath, in and out will improve economy. Sadly the extra performance is used by the driver. This generally makes economy worse.

[easytime]

Tell you what, I get 270 miles from super unleaded, my heart always says dont fill on super, too expensive, but my brain says fill on super as it will yield more miles than you'd save in regular.

[talkingcars]

I was achieving less than 1mpg more on super over normal.

[easytime]

I was achieving less than 1mpg more on super over normal.

Wow, I dont know why, I get real extra miles.

[Deckz]

I live 1.8 miles from work, she is not even warm when I knock her off at work. Also there are only 2 motorways in N. Ireland! And none of them near me!



Where ya at mate?

[easytime]

Where ya at mate?

Bangor, you local?