Improve BHP without turbo

[swampy_donkey]

Ahh thanks Andy. The K&N is £135 at the moment, anything else around this price point?

[AndyM]

I'm not 100% sure as I'm not in the market right now (Markiii + K&N panel is fine for me at the moment). However when I first got the car I liked the look of the BMC. Think it comes in a bit higher at about £180 ish though.

If I was in your shoes though (you did ask for thoughts  s;) s;)  ) I'd put a Markiii pipe on (or even the DIY alternative) and put your pennies towards an exhaust and a can of carb cleaner for the MAF. Then maybe swap out the filter at your next service for something slightly better performance wise.

Once that's done its probably saving time until you can get the ECU/map/dyno to bring it all together and get some real benefit from it all.

[Wabbitkilla]

You have your options, pick one and jfdi.
Everyone is going to have a different opinion about what works.
Whatever you do, don't fit one of those horrible Blitz metal filters.

[nathanMR2]

The BMC pannel filter is well regarded. Its what i run and is supposed to be the same as TTE use for theirs

[jonty]

i would have thought would ribbed piping like seen above it would cause a poor air flow, a smooth pipe would allow the air to flow smoothly through rather than the ribbed pipe which i'm sure would be very disruptive. probably still an improvement on the stanard, just would rather a smooth pipe.

That's an interesting point.
The standard intake pipe probably narrows for a reason. A venture effect is created causing the air to flow faster as it enters the airbox; there will be a drop in pressure at that point but the kinetic energy in the air will be higher.
The 'straight through' Mark iii type pipe will have a lower air entry speed as it enters the airbox but a higher pressure and lower energy.
My simplistic interpretation of that is that is that the oe pipe will generate slightly more low end torque and that the 'straight through' pipe will transfer that slightly up the rev range.
If the piping is ribbed on the inside then there will be significant flow  turbulence which may affect both flow speed, pressure and energy.

That could be rowlocks so we now need the person with the degree in Physics.  s:lol: :lol: s:lol:  
.

air is drawn in by the piston moving down creating a vacuum, and the bigger the pressure difference the more air will be shifted. You never want low pressure into an airbox as this reduces the pressure delta, so a venturi on the way into the box is not desirable. As an extreme case F3 cars run a really small restrictor, which chokes the air as it reaches the speed of sound and gives very low pressure, so they use a diffuser behind the restrictor to slow the air down as much as possible and therefore recover pressure to make best power.

As for the pipe, a low cost ribbed pipe is indeed bad for flow because of turbulence - but if you buy some proper motorsport 2 layer ducting this has a smooth inner surface and avoids this problem.

I work for a large auto OEM, and I've got to say that most things are dictated by emissions and NVH not power, so there will defnitely be room for improvement - don't think just cos Toyota did it in a certain way that this is optimised for performance.

[Wabbitkilla]

That's a good point Jonty.

Road cars have all sorts of rules to obey, noise emmissions, chemical emmissions, the list goes on.
In motorsport and car modifying then performance is what you're aiming at, hence measured velocity stacks and more open exhausts.

If you're going to modify a cars intake then it's also worth modifying the exhaust to balance out stuff. The science can get boggling, which is why it's useful for people to list modifications with power gains proven so others can educate themselves and aim for proven results.

Tuning for more power is not cheap, you can get minor gains that give your butt dyno nice results. A long time ago someone on here compared the standard air box and various filters with the various after-market cold air intakes.  It was found that with the exception of the PPE and AEM intakes not a lot was to be gained by fitting a CAI. But the sound they made was more satisfying and gave you the sense that power was improved. Power was actually improved in places but lost in other places of the curves. TBH the only way I would take my Apexi power intake off would be if I got a PPE intake cheap.   s:wink: :wink: s:wink:  

You can also do a lot of damage with a bad cheap intake, we have seen one or two cars use the ebay cheapies and end up fubar, but then some people are running replica AEM intakes and they seem fine ... so far. One of the problems with most of these "Cold Air Intakes" is they increase intake temperatures ... which loses you power PPE and AEM avoid this by moving where they get the air from.

[swampy_donkey]

Thanks for the advice guys, I definitely agree with the placebo effect of a lot of modifications. I took the car to an F1 support racer who specialises in tuning (mostly classic racers) and showed him the bottleneck that the markiii pipe remedies. He agreed changing that would probably  be beneficial, but was sceptical about full after market intake systems (unless spending a lot of money). He also advised to get the full benefit of a markiii type pipe it should definitely be heat wrapped.

I have got on order now a silicone pipe to replace the bottleneck pipe and I have in my possession to install tomorrow a K&N panel filter. I will let you know how it goes! Unrelated to this I also have some half decent oil and a new oil filter to fit, as well as fixing the rattling from the 'pull' label. Busy day!

[James and his MR2]

Did the k+n panel filter and silicone pipe make it sound any better swampy?

[swampy_donkey]

Hi James,K&N made a slight difference to the sound,a tiny but throatier from about 3k rpm.  Bad news is I got the silicone pipe but it's too short(about 20-25mm each end). Good news is I picked up a Markiii pipe tonight from Dogsy on the forum so I'm installing that on the weekend. I'll feed back results. Cheers, Rob.

[James and his MR2]

Hi James,K&N made a slight difference to the sound,a tiny but throatier from about 3k rpm.  Bad news is I got the silicone pipe but it's too short(about 20-25mm each end). Good news is I picked up a Markiii pipe tonight from Dogsy on the forum so I'm installing that on the weekend. I'll feed back results. Cheers, Rob.

yea ive got the K&N filter too  s:) s:)  does make a small diffrence to be fair slightly louder. Nice on the markiii pipe Ill be waiting a while for mine I think. Yea let us know results  s:) s:)  If it dosnt make enough of a diffrence ill just go all out and buy an exhaust I think. Maybe removing my precats might make it louder too

[swampy_donkey]

yea ive got the K&N filter too  s:) s:)  does make a small diffrence to be fair slightly louder. Nice on the markiii pipe Ill be waiting a while for mine I think. Yea let us know results  s:) s:)  If it dosnt make enough of a diffrence ill just go all out and buy an exhaust I think. Maybe removing my precats might make it louder too

I was thinking an exhaust, but they're very expensive. I got a quote of £450 + £100 fitting at Cobra... Just not worth it IMHO.

[James and his MR2]

yea ive got the K&N filter too  s:) s:)  does make a small diffrence to be fair slightly louder. Nice on the markiii pipe Ill be waiting a while for mine I think. Yea let us know results  s:) s:)  If it dosnt make enough of a diffrence ill just go all out and buy an exhaust I think. Maybe removing my precats might make it louder too

I was thinking an exhaust, but they're very expensive. I got a quote of £450 + £100 fitting at Cobra... Just not worth it IMHO.

Yea I agree 100% mate when my car is only worth 2k in general(even if it is worth more than that to me). I might get a quote for a custom exhaust from longlife they can range quite a bit or maybe look out for a 2nd hand one on ebay/forums. Btw we did just pay £70 and £82 for a pipe   s:shock: :shock: s:shock:    s:shock: :shock: s:shock:

[swampy_donkey]

yea ive got the K&N filter too  s:) s:)  does make a small diffrence to be fair slightly louder. Nice on the markiii pipe Ill be waiting a while for mine I think. Yea let us know results  s:) s:)  If it dosnt make enough of a diffrence ill just go all out and buy an exhaust I think. Maybe removing my precats might make it louder too

I was thinking an exhaust, but they're very expensive. I got a quote of £450 + £100 fitting at Cobra... Just not worth it IMHO.

Yea I agree 100% mate when my car is only worth 2k in general(even if it is worth more than that to me). I might get a quote for a custom exhaust from longlife they can range quite a bit or maybe look out for a 2nd hand one on ebay/forums. Btw we did just pay £70 and £82 for a pipe   s:shock: :shock: s:shock:    s:shock: :shock: s:shock:

Yeah that's what I'm thinking. I was thinking 2nd hand too, there is a thread about a Che Lotus style, that looks pretty good to me.

[James and his MR2]

Hmm im not liking the center exit style, looks a bit porsche to me. But then i dont like the quad exhausts either so maybe im a bit picky haha. I love it one each side  s:) s:)  I love the exhaust exit on the clio 200 moulded into the diffuser LUSH lol

[Flipside]

Any exhaust you get, fit yourselves it's very easy.

[swampy_donkey]

Yes two single exits are better than quads IMHO too. True, exhausts can be an easy fit, most garages charge around £30ish I think. Which is what annoyed me about the cobra quote, £100 is just greedy.

[nathanMR2]

You need to consider that bolts being removed from a car of this age, especially around the exhaust area can be notoriously difficult. They can often break or sheer. Whilst a £100 is a little steep they are probably covering their backs should something become less simple than a bolt off, bolt on job. It is by far a £30 job and if I was in the trade there is no way id be charging that. It's an hours work at the very least and im sure that garages changing £30 per hour these days would be out of business very soon.

It is a DIY job and I've installed and removed a few now. But give yourself around half a day to do it especially if you havent done it before. Also consider replacing the bolts/springs that run thought the cat pipe into the exhaust as they are likely to be rusted beyond reuse.

[James and his MR2]

Thats true to be fair. I have been quoted £70 for gaskets and bolts for the pre-cat removal!

[swampy_donkey]

You need to consider that bolts being removed from a car of this age, especially around the exhaust area can be notoriously difficult. They can often break or sheer. Whilst a £100 is a little steep they are probably covering their backs should something become less simple than a bolt off, bolt on job. It is by far a £30 job and if I was in the trade there is no way id be charging that. It's an hours work at the very least and I'm sure that garages changing £30 per hour these days would be out of business very soon.

It is a DIY job and I've installed and removed a few now. But give yourself around half a day to do it especially if you havent done it before. Also consider replacing the bolts/springs that run thought the cat pipe into the exhaust as they are likely to be rusted beyond reuse.

Fair point, I thought £30 an hour with no parts is about right for a mechanic at a garage - if not I'm way off!

I was thinking about doing it myself if I got one, like you say, half a day and replacing the bolts etc as I go.

On a side note, do you (or anyone) happen to know the bolt size that holds the underneath shield things on?

Cheers

Rob

[James and his MR2]

For the heatshields? You can use any bolts I used M8 nuts and bolts to solve my rattle

[swampy_donkey]

Cheers James. I'll get that sorted ASAP. Some sheered off on the recent oil change.

[swampy_donkey]

Does the markiii pipe need jubilee clips? I've seen a couple of installation guides. However, does it go in or out of the pipes in the car? I noticed the weld on the inside of the pipe isn't too neat. Should that be a concern? Could I file it down?

[swampy_donkey]

Hi folks, another bit of advice required if poss please.

After installing the markiii pipe, would it be advisable to reset the ecu?

If so, is that easy to do?

Cheers

[nathanMR2]

Jubliee clips would be a good idea. Its pretty tight as it is but it wouldnt hurt as long as you dont over tighten.

I see no problem with filing the weld a little.

Resetting the ECU would be advisable. To do this disconnect the battery for 30mins and reconnect. This should reset the ECU.

[swampy_donkey]

Jubliee clips would be a good idea. Its pretty tight as it is but it wouldnt hurt as long as you dont over tighten.

I see no problem with filing the weld a little.

Resetting the ECU would be advisable. To do this disconnect the battery for 30mins and reconnect. This should reset the ECU.

Thanks Nathan. That's this weekends job sorted then!