438 Cams, RS2 Inlet, PMS Exhaust... bhp?

[GasManLS7]

My Clio 182 Cup currently has matched inlets with KTR induction kit, 438 cams, decat and piper exhaust and was mapped by revlimit tuning at 189.3bhp @6450rpm and 163.2ft/lbs @5550rpm.

I have a 172 single race exhaust from PMS to go on and will be getting their race manifold and one of the new RS2 inlets, anyone have any idea what kinda performance these will generate after a map? Is there a limit the standard ECU can produce? Car is used for sprint and hillclimbs and the occasional track day so performance is key.

 

[Robbie Corbett]

Not sure you will see much improvement from a different exhaust manifold - the 182 unit is pretty well designed from the factory. I would guess with an RS2 you will be knocking on the door of 200bhp. I would save the money and put it towards head porting or a higher comp build if your after close or more than 200bhp.

No ecu limit, there is a limit to how much fuel standard injectors can flow. Standard injectors are 250cc/min and tbh they will be basically flat out at 200bhp assuming fuel reg is 3bar.

Would be best to find out from your previous tuner what the maximum duty cycle was for your last session, if your over 90% at 190 I would be looking to upgrade to megan rs which are circa 400 cc/min I believe. The 197 used slightly larger injectors than the 182 so Renault obviously thought along similar lines (need bigger injectors as you approach 200bhp).

Some people seem to be achieving 200 bhp on standard injectors but I can assure you the duty cycle will be close to 100% which is poor.

 

[GasManLS7]

Do the 197 and megane rs injectors have the same spray pattern as the 182 ones? And will they all fit straight into the rs2 inlet?

182 manifold as good as the pms race manifold on an engine my spec?

 

[Greeny.]

FYI Engine Dynamics swapped my injectors for 197 items when mapping my car with 421catcams as the 182 items were at 95% duty, im running matched inlets, ktec induction kit, janspeed supersport exhaust and at the time a de-cat.

Out of interest where are these new RS2's? I thought the last time they were available new was about 10 years ago back in the JMS days.

 

[Robbie Corbett]

Do the 197 and megane rs injectors have the same spray pattern as the 182 ones? And will they all fit straight into the rs2 inlet?

182 manifold as good as the pms race manifold on an engine my spec?

I should image we are talking marginal gains for a relatively large outlay and a bellend to install with engine in the car. Other modifications will give more power per £. The 182 exhaust manifold is well designed from the factory. Your spec isn't outrageous and many with similar or better specs have used the standard 182 manifold at over 200bhp.

I believe the meg injectors are more similar to the 182, although both fit.

Just to be clear about my point above - you might not have realised this and someone might correct this however I can't see how you could remove the 182 manifold without either removing the steering rack or the engine, its all very tight in there! If your removing the engine then I would still be spending the money in different areas for a bigger power improvement.

 

[Robbie Corbett]

FYI Engine Dynamics swapped my injectors for 197 items when mapping my car with 421catcams as the 182 items were at 95% duty, im running matched inlets, ktec induction kit, janspeed supersport exhaust and at the time a de-cat.

Out of interest where are these new RS2's? I thought the last time they were available new was about 10 years ago back in the JMS days.

Might be talking about the Turkish knock offs?

 

[GasManLS7]

I don't think they're Turkish knock offs, JMS have been making them again and selling them on Facebook since 2019.

https://m.facebook.com/RS2intake/

Think it's JMS anyway.

So the other modifications you suggest before looking at manifold, is it all engine internals?

 

[Robbie Corbett]

If your sorted on the boring gearbox, suspension and brake front then yes I would personally do some choice engine upgrades. I know the RS2, cams and ported head work very well together.

I had my engine out not so long ago and I'm still kicking myself that I didn't do more, would have been prime time to have head sorted and potentially look into 197 pistons/rods.

All depends on what your removing next tbh - like if your planning to remove the engine at any point you get access to lots of options. If I remove the box again I will be doing a lighter flywheel for example.

 

[GasManLS7]

Yeah happy with gearbox, brakes and suspension for now. No plans for taking the engine out any time soon, so probably just rs2 and remap before season starts again

 

[leeds_182]

I’m old. I just read this and wanted to type don’t bother but I stopped myself.

well, I kind of did.

 

[bashracing]

You'll put in quicker times by spending money on a gripper and 5.1 CWP.
all you do by increasing power is move it up the rev range and spend the whole run in second gear (loosing time)

 

[GasManLS7]

Already got a gripper thanks. I'm happy with gearbox, suspension, brakes, geo, wheels, tyres, weight, my body weight, tuition etc etc

Just looking for advice on where to go next with the engine.

 

[bashracing]

fair enough. shorter intake runners will reduce mid range torque and that doesn't bode well with the 438 cams on standard timing marks, re-time them to 421 cam timing for a better match with something like a RS2.
personally id be going itb's and well ported head

 

[Chambers_RS]

I wish I stayed on the RS2 manifold and grpN timing. Drivability was spot on, simple and reliable.

 

[GasManLS7]

Was your engine untouched, just bolt ons? That's pretty much the spec I'm looking at but with 438s instead of group n timing. Did you have different injectors and what bhp/torque were you getting?

Also what air box is that?

 

[Yarp]

I should image we are talking marginal gains for a relatively large outlay and a bellend to install with engine in the car. Other modifications will give more power per £. The 182 exhaust manifold is well designed from the factory. Your spec isn't outrageous and many with similar or better specs have used the standard 182 manifold at over 200bhp.

I believe the meg injectors are more similar to the 182, although both fit.

Just to be clear about my point above - you might not have realised this and someone might correct this however I can't see how you could remove the 182 manifold without either removing the steering rack or the engine, its all very tight in there! If your removing the engine then I would still be spending the money in different areas for a bigger power improvement.

the 182 manifold comes out no bother with both engine and subframe in situ. It’s quite a recip blade heavy process though 🤣

 

[Robbie Corbett]

Torque curve

fair enough. shorter intake runners will reduce mid range torque and that doesn't bode well with the 438 cams on standard timing marks, re-time them to 421 cam timing for a better match with something like a RS2.
personally id be going itb's and well ported head

Torque curve on RS2 and group N looks spot on. itb's would do nothing for low/mid range torque lol

You won't better that for a torque curve.

 

[Robbie Corbett]

the 182 manifold comes out no bother with both engine and subframe in situ. It’s quite a recip blade heavy process though 🤣
View attachment 1521059

Good work mate, when's the refit? lol

 

[Eddie555]

Today i completed everything i wanted to do. My spec.
197 cams with 8deg advance inlet.
197 injectors at 85%.
Port matched inlets.
182 manifold.
Ktec decat and Resonated supersports exhaust.
Ktec induction kit
TTV lightened flywheel
E'PAS

Mapped at Efi.

 

[Robbie Corbett]

Nice! Very decent torque too - you must be dead chuffed.

 

[bashracing]

Torque curve

Torque curve on RS2 and group N looks spot on. itb's would do nothing for low/mid range torque lol

View attachment 1521060

View attachment 1521061

You won't better that for a torque curve.

You're producing 13ft lb less than the op and only producing the same HP but at 1000rpm higher rpm

the argument towards against the RS2 is that 438's suit standard inlet manifolds as the long runner lengths work nicely with the high lift short duration of 438 timing but are nearing the upper limit of the standard inlet power wise,

by fitting the RS2 you'll loose the mid torque on 438 cams at a cost of a few hp high up the revs which due to the JC5's poor gearing isn't that useable on Hillclimbs,

The argument to fit itbs over an RS2 is the ability for further tuning potential

 

[Eddie555]

Nice! Very decent torque too - you must be dead chuffed.

Thanks. Yea im well happy with my results. Just need to get back out on track and use the thing..

Sent from my SM-G977B using Tapatalk

 

[frayz]

The RS2 torque curve is completely flat, so yes it has a little more torque than stock between 2500-300rpm but it loses out everywhere else at the gain of some bhp right at the top or the rev range. Pointless unless you're on a circuit where you're at 7k all day long. For hillclimbs & sprints, the torque right through the middle will be what makes you quicker.
Also if you saw the quality, fit and finish of one of the new ones you wouldn't pay £100 for it, leave alone £1300!!

 

[Ex-User (99307)]

Torque curve

Torque curve on RS2 and group N looks spot on. itb's would do nothing for low/mid range torque lol

View attachment 1521060

View attachment 1521061

You won't better that for a torque curve.

I think you could better that with ITBs and some different timing.

 

[Yarp]

Good work mate, when's the refit? lol

I’m going full Haynes manual on that one: “Refitting is the reverse of removal” 😂

 

[Greeny.]

The RS2 torque curve is completely flat, so yes it has a little more torque than stock between 2500-300rpm but it loses out everywhere else at the gain of some bhp right at the top or the rev range. Pointless unless you're on a circuit where you're at 7k all day long. For hillclimbs & sprints, the torque right through the middle will be what makes you quicker.
Also if you saw the quality, fit and finish of one of the new ones you wouldn't pay £100 for it, leave alone £1300!!

Are they that bad? I was going to maybe consider one next year.

 

[Robbie Corbett]

The RS2 torque curve is completely flat, so yes it has a little more torque than stock between 2500-300rpm but it loses out everywhere else at the gain of some bhp right at the top or the rev range. Pointless unless you're on a circuit where you're at 7k all day long. For hillclimbs & sprints, the torque right through the middle will be what makes you quicker.
Also if you saw the quality, fit and finish of one of the new ones you wouldn't pay £100 for it, leave alone £1300!!

Can't talk about quality of the new ones but I'm all for a flat torque curve even if that means losing a touch of low end and mid range torque. Although looking through some of the old dyno graphs on here some cars with RS2 inlets seem to drop a load of mid range for only a touch above 6k which as you day is an odd price to pay, suspect the RS2 could have done with being longer or tuned for a lower rpm.

My M3 is basically flat from 3k to 7k. Makes for a slightly undramatic but very predictable car, also like the feeling of consistent pull right up to the limiter rather than tailing off.

Out of interest blue line is GT4... ends up being a preference/subjective thing I guess but same is true for all the bikes I've ended up keeping - the ones which ride well and easier to ride quickly have all had a decent section of flat torque.

Saying that - don't know what I'm raving about, I'm never going to stick an RS2 on mine and I wouldn't change a thing about eddies results above - although would be intrigued to see results for same spec with a shorter manifold looks like it could do 215-220.

 

[frayz]

Are they that bad? I was going to maybe consider one next year.

Absolutely dire from what i saw mate. Im not talking photos either. Im talking had it in my hands and looked all over it, inside and out. Parts not finished, parts missing, threads not dapped, holes not drilled, the carbon finish is shocking too. The best bit is the Jenvey bit as that's high quality as you would expect from Jenvey.

I was lined up to buy one last year, but after seeing them first hand, i genuinely wouldn't pay £100 for one

 

[Robbie Corbett]

Are they that bad? I was going to maybe consider one next year.

Some people absolutely love them - Chip who was a user on here for many years whos opinion I would trust was a big fan after installing one. I would have no issue with 200bhp and loosing a touch of (10ft.lbs say) of the midrange peak. Can't disagree with Frayz's points though. If I was really into making Clio's fast I would just have a rotrex hanging off it.

I have this waiting for the car I do actually want to make fast, just need to draw up the mounts

 

[Robbie Corbett]

I think you could better that with ITBs and some different timing.

View attachment 1521097

Nice!

 

[frayz]

Can't talk about quality of the new ones but I'm all for a flat torque curve even if that means losing a touch of low end and mid range torque. Although looking through some of the old dyno graphs on here some cars with RS2 inlets seem to drop a load of mid range for only a touch above 6k which as you day is an odd price to pay, suspect the RS2 could have done with being longer or tuned for a lower rpm.

My M3 is basically flat from 3k to 7k. Makes for a slightly undramatic but very predictable car, also like the feeling of consistent pull right up to the limiter rather than tailing off.

View attachment 1521103

Out of interest blue line is GT4... ends up being a preference/subjective thing I guess but same is true for all the bikes I've ended up keeping - the ones which ride well and easier to ride quickly have all had a decent section of flat torque.

Saying that - don't know what I'm raving about, I'm never going to stick an RS2 on mine and I wouldn't change a thing about eddies results above - although would be intrigued to see results for same spec with a shorter manifold looks like it could do 215-220.

Eddies graph above between 3500-6500 has more torque, than the RS2. Even when at the redline its only just below what an RS2 is making.
So to me, the stock plenum is better for a road/sprint/hilclimb car and the RS2 only really sees any value in outright bhp on track. However if that was your main goal, id personally just go to ITBs.

Just my thoughts.

 

[Greeny.]

Some people absolutely love them - Chip who was a user on here for many years whos opinion I would trust was a big fan after installing one. I would have no issue with 200bhp and loosing a touch of (10ft.lbs say) of the midrange peak. Can't disagree with Frayz's points though. If I was really into making Clio's fast I would just have a rotrex hanging off it.

View attachment 1521104

I have this waiting for the car I do actually want to make fast, just need to draw up the mounts

I like NA tbh, plus I have 421’s already so the RS2 I was hoping would be a relatively cheap bolt on compared to ITBs.

Do we know who is actually making these new units? One of the original JMS boys?

 

[Robbie Corbett]

You're producing 13ft lb less than the op and only producing the same HP but at 1000rpm higher rpm

the argument towards against the RS2 is that 438's suit standard inlet manifolds as the long runner lengths work nicely with the high lift short duration of 438 timing but are nearing the upper limit of the standard inlet power wise,

by fitting the RS2 you'll loose the mid torque on 438 cams at a cost of a few hp high up the revs which due to the JC5's poor gearing isn't that useable on Hillclimbs,

The argument to fit itbs over an RS2 is the ability for further tuning potential

Can't disagree with that, see you point regarding cams and see you are talking total sense Agree that would be a poor match. Im still not a massive fan of throttle bodies on these but more due to the need to cut your slam panel etc. No one can argue with the noise.

 

[Robbie Corbett]

Eddies graph above between 3500-6500 has more torque, than the RS2. Even when at the redline its only just below what an RS2 is making.
So to me, the stock plenum is better for a road/sprint/hilclimb car and the RS2 only really sees any value in outright bhp on track. However if that was your main goal, id personally just go to ITBs.

Just my thoughts.

Hard to argue with that Would still be interested simply because his spec is making such a decent chunk of torque, most RS2 equipped cars are a flat 150lbf.ft, if you could do 160 with the RS2 you would be making some decent gains above 6k. But obviously if your on hill climbs (or the road!) thats not helpful.

 

[Robbie Corbett]

I like NA tbh, plus I have 421’s already so the RS2 I was hoping would be a relatively cheap bolt on compared to ITBs.

Do we know who is actually making these new units? One of the original JMS boys?

There were some Turkish (I think?) knock offs, someone had them on here a while back and they looked alright in the pictures - looked like a straight copy available in glass of cf. Certainly looked better than what Frayz has said about the new RS2!!

Rotrex type blowers tend to feel very N/A, a mate has one on a type R and I had a smaller one (than pictured above) on a 328i for a while and both feel/felt very natural. Weirdly they are basically the worst compromise between a turbo and an eaton type blower but they have the big advantage of fitting where most other things dont.

 

[Ex-User (99307)]

I like NA tbh, plus I have 421’s already so the RS2 I was hoping would be a relatively cheap bolt on compared to ITBs.

Do we know who is actually making these new units? One of the original JMS boys?

Definitely not JMS. The design and rights were sold to Russ Fitch who never really got anywhere with it so he sold the design on again to another chap.

 

[Eddie555]

Eddies graph above between 3500-6500 has more torque, than the RS2. Even when at the redline its only just below what an RS2 is making.
So to me, the stock plenum is better for a road/sprint/hilclimb car and the RS2 only really sees any value in outright bhp on track. However if that was your main goal, id personally just go to ITBs.

Just my thoughts.

My main goal was to extract as much as i could (safely) with all parts that are available at a drop of a hat. I wanted it so other people could see that you dont have to use a whole host of aftermarket parts to generate a decent amount of power. Yes we all are different and prefer spending our money on stupid crap but with this car i wanted it to be easy to fix and have parts easily available to swap and change "when" not "if" they break.

Sent from my SM-G977B using Tapatalk

 

[masekwm]

Definitely not JMS. The design and rights were sold to Russ Fitch who never really got anywhere with it so he sold the design on again to another chap.

That's a Glasgow phone number

 

[GasManLS7]

My main goal was to extract as much as i could (safely) with all parts that are available at a drop of a hat. I wanted it so other people could see that you dont have to use a whole host of aftermarket parts to generate a decent amount of power. Yes we all are different and prefer spending our money on stupid crap but with this car i wanted it to be easy to fix and have parts easily available to swap and change "when" not "if" they break.

Sent from my SM-G977B using Tapatalk

Think Eddies philosophy is similar to mine, was hoping that the rs2 would be a quick and easy improvement and also allow me to free up space/ditch weight in the bay. Seems like the new RS2 might not be all its cracked up to be and actually my current figures are quite good for the spec.

Was trying to avoid ITB's for now as the cost and work required is quite prohibitive. When you factor in the rad, slam panel, throttle cable, ECU etc it made the RS2 seem a lot more appealing.

I think Will Roberts has the only Clio thats consistently beaten me up Harewood and he has ITB's, guess thats the way to go.

 

[Kev@KAM]

You'll put in quicker times by spending money on a gripper and 5.1 CWP.
all you do by increasing power is move it up the rev range and spend the whole run in second gear (loosing time)

What does that top out at? I'd have thought its too short for most track use...