Toyosports Exhaust Manifold - performance wise

[J_gadd4]

Well all I can say is don't bother, unless your Renault manifold is broken.

Renault:



Toyosports:




Mine had lost 6bhp from putting the Toyosports manifold on it, so that's a bit disappointing. Although there could be any number of factors which could cause that, like spark plugs being older and having suffered the engine running lean after fitting the new manifold but before mapping, and there's a possibility that I over-oiled my ITG filter after cleaning it. But in any event,

Paul managed to get it back up to 188.3bhp after a good deal of effort, which is 0.8 more than what it ran with the standard manifold before mapping. I'd like to know what mine would have got with a map on the standard manifold - probably more than that. The final run was with the manifold glowing though, so heat soak might have been an issue!

Anyway, I'd say it was worthwhile if you have a broken manifold, but if yours is fine, just leave it and spend the money elsewhere. It does drive much more smoothly now, so I'm pleased in that respect. And it did all come in less than the cost of a new manifold from Renault. But I am a little disappointed because in the end I think I've sacrificed everyday drivability with it being a bit more drony (and not in a good way) and having more vibration from the Powerflex insert, and ended up with basically what I used to have... with my wallet being £1k lighter. The joys of Renault Sport ownership, eh?

Joe

But they are good power gains low down though, are you just running the toyo manifold and itg ? Or do you have other parts on the car?

 

[lostmotel]

But they are good power gains low down though, are you just running the toyo manifold and itg ? Or do you have other parts on the car?

Oh yeah it's like having another engine strapped on between 2,500-300rpm! For normal driving it's really nice now, much more driveable out of second gear corners for example. And yeah it's just got the ITG panel filter and the Toyosports manifold. Like I said, I'd be interested to see what Paul could have got out of it with the standard part on.

I'll make sure to take it back and see if it runs any better when a bit cooler, just to satisfy my curiosity more than anything.

Joe

 

[Raptor6767]

What's the optimal AFR on our cars 5-7500rpm?

 

[J_gadd4]

Oh yeah it's like having another engine strapped on between 2,500-300rpm!

Sounds very sarcastic , but it will be rely hard to drive normally with out having the front cat in because there is no back pressure which creates the flat spots

 

[TB Rich]

Absolutley, the std manifold is poor. Short small primaiers and also having a slightly larger primary diameter compared to the exhaust port is often a good method of ensuring to minimise returning low pressure waves from entering the cylinder on the intake stroke (under valve overlap).

I'll post up results when my R3 is fitted.

Really!
Have you actually removed one & had a look ?
The primaries are way smaller than the head ports, crap flex joints, pipes poorly finished at head plate (squashed & misaligned pipes, crap welds).

Yes the Renault manifold design is ok but get a Toyosports manifold & actually have a look at it first hand. The difference in build, finish & design is night & day.

Unfortunately like some other parts on the Clio III (engine mounts, strut tops etc), the oem suppliers to Renault leave a lot to be desired in build quality.

 

[lostmotel]

What's the optimal AFR on our cars 5-7500rpm?

Looking at other print outs from the RR printout thread, it looks to vary over that rpm range between 12.5:1 and 13:1 or lambda 0.85 to 0.88.

Sounds very sarcastic , but it will be rely hard to drive normally with out having the front cat in because there is no back pressure which creates the flat spots

In retrospect it was bloody awful driving it before the map. It's made a huge difference to driveability and refinement - it feels OEM now. The thing about back pressure is it's usually a bad thing - in a properly tuned exhaust system. But I expect the whole intake, timing and exhaust will have been optimised for there being the pre-cat and the back pressure that it creates. So for instance I'd expect the Y-pipe to cause problems, never mind a completely different manifold design.

 

[TB Rich]

Looking at other print outs from the RR printout thread, it looks to vary over that rpm range between 12.5:1 and 13:1 or lambda 0.85 to 0.88.



In retrospect it was bloody awful driving it before the map. It's made a huge difference to driveability and refinement - it feels OEM now. The thing about back pressure is it's usually a bad thing - in a properly tuned exhaust system. But I expect the whole intake, timing and exhaust will have been optimised for there being the pre-cat and the back pressure that it creates. So for instance I'd expect the Y-pipe to cause problems, never mind a completely different manifold design.

Quite correct, back pressure is a bad thing, it's a common mis conception that back pressure is good for low end torque. No it's not, it's just that things like having a cat causing a restriction which increases the gas velocity (which actually lowers internal pressure!!) and therefore helps the bottom end because at those rpm's the pressure delta between the cylinder and exhaust is better suited. Remember you can't tune a non active system to be optimal at all rpm's. When you remove the cat the overal amount of flow increases which in turn helps with the higher rpm's. The slower gas actually causes more internal pressure and the engine at low rpm can't make any use of the overal increase in flow - hence the bottom end dropping on a de-cat for example.

*Basically what people say is correct, but the termionlgy used is incorrect - back pressure, pah!!*

It's a big friggin subject and beyond me or at least beyond what I can be arsed to learn more to the point!! Primaries and collector design are the 2 most important aspects and you may find that the Toyo is poor or just ill suited in either one of those. Bash in a set of cams though and everything changes because the timing will radically alter, the cam is probably the most important component to design the engine peripherals around (exhaust lengths, induction lengths etc).

 

[J_gadd4]

toyo manifold yes or no ? that is the question

 

[smoggy mark]

toyo manifold yes or no ? that is the question

Yes you need to do something to keep up hahaha! :thumbsup:

 

[J_gadd4]

Yes you need to do something to keep up hahaha! :thumbsup:

ha dont make me laugh mark :thumbsup:

 

[TomPenn]

Sorry to resurrect this thread but would like your advice. Flexis have gone in standard Renault manifold. I've got a couple of options, which would you go for based on your experience? A) fit the toyosport for circa £500 Inc labour b) ktec can can weld in some new flexis on the Renault manifold for about £500 c) get the ktec manifold fitted for £900

 

[suj]

If you modify, you will need a remap (Toyo or KTEC manifold) as any exhaust modification causes a flat spot, so you will need one or you'll hate this flatspot.

Questions:
1) Do you want to start modifying the car, or are you happy with current setup / performance?
2) If answer to 1) is you want to put an exhaust on it also, then yes consider the 2 manifold options.
3) If answer to 1) is you are happy with current performance / noise, then go for new flexis on your standard manifold

 

[TomPenn]

Really appreciate that @suj Will go with welding in the flexis if I need to factor in the cost of a remap. Thanks

 

[suj]

Really appreciate that @suj Will go with welding in the flexis if I need to factor in the cost of a remap. Thanks

No worries, some people live without a map, but why would anyone live with a flatspot between 2000 and 3000rpm, especially if you use it daily, it's like where most of your driving is!

I did same as you are, I got standard ones welded up, I also went from a Milltek that the car came with, for a standard system, I prefer it that way (yes I'm getting old before my time lol).

 

[Ichigo27]

Following this, previous owner had a Toyo manifold fitted, & I never noticed a flat spot.. However it does have a "powerchip" cs1 box cable tied into the battery cover. Now I was going to remove this as it's not a particularly expensive thing and I was dubious it even helped performance, now I'm wondering if this was added to help remove the flat spot?