Anybody in the south-west with cams, an RS2 or TB's?

[Jardo]

Basically...

I am looking to take my car a step further, and my options are TB's or an RS2 and cams. Before spending my money and choosing which route to go down I would like a go in a cammed car, and a car with the mentioned intake upgrades.

So, anybody going to show off their car to me? I am in Plymouth and can meet just about anywhere

 

[McGherkin]

Pretty sure there's at least one. I seem to recall Chip Mk1 having a RS2 inlet (or similar)

 

[Aaron182.]

I don't know of anyone it Devon/Cornwall. (the real southwest). But theirs a few RS2's in Southampton

 

[Jardo]

I don't know of anyone it Devon/Cornwall. (the real southwest). But theirs a few RS2's in Southampton

Southampton is for gays, but it's close to home. Might have an ask next time I go back.

Eurgh, I have money burning a hole and I want to buy one of the other but I can't commit without knowing. Think I am going to go with the RS2.

 

[Nick172Cup]

Do you want out and out power or drivability? Is the car for track or just a daily?

I had an RS-2 and loved it, driven an ITB'd car and it felt good also. But I'd save the extra pennies and go with an RS-2 with grp. N timing tool and not both with cams either. Money better spent elsewhere tbh.

 

[Jardo]

I want drivability, I enjoy fast road driving but it is just too risky. I enjoy driving a lairy car daily and having something special.

I drive in the ASW Hill Climb and do regular track and airfield days. The Clio is a whole new venture for me from Audi's so it is all new.

I am pretty set on the RS2 now tbh, but I have read that 428's can create a hole in the torque curve mid range? What is the group n timing tool?

 

[Nick172Cup]

I want drivability, I enjoy fast road driving but it is just too risky. I enjoy driving a lairy car daily and having something special.

I drive in the ASW Hill Climb and do regular track and airfield days. The Clio is a whole new venture for me from Audi's so it is all new.

I am pretty set on the RS2 now tbh, but I have read that 428's can create a hole in the torque curve mid range? What is the group n timing tool?

IIRC you need a FBW throttle body for Hill climbs? Correct me if I'm wrong. Anyways the makes the RS-2 fit into that category well.

There's no doubt that a set of catcam 438's will give you similar if not more power in some cases but in my opinion torque duration over peak torque makes for a very good daily driver and also then when on track is very useful which the RS-2 does well.

The group N tool that I spoke about is a relatively new thing to pop up over here that seems to work exceptionally well with the RS-2. Average results from in the Uk with just normal timing on the RS-2 ranged from 180-195bhp with over 150lb/ft torque, it hasn't been done over here yet with the group N tool but in France there's guys running over 200bhp easily with better torque figures to match. I believe James from Stone Automotive is waiting for someone to try this to see if the correlates with the figures over in France.

 

[Chip-mk1]

We're in Taunton and one of our 172's has an RS2 on it, you are welcome to have a drive of it one weekend if you like mate.

TBH its probably not the best example as it was only in the 160s bhp wise to begin with (its a 140K mile car) and probably only 180 or so now compared to some that make 190+ but it still really well demonstrates the way that the rs2 just loves to hold onto the torque until far up in the rev range.

Ive got very used to driving it now and I must confess that I hate our other (standard) 172 now by comparison in terms of power delivery.


Ultimately though, bodies will give more power, so it depends what you are after, as a fast road car and occasional trackday car though (this car only does about half a dozen trackdays a year normally as we have other dedicated trackday cars to use instead for most of the trackdays we do) we both really enjoy it.





My mrs got instruction in the RS2 car at bedford on the recent renaultsport day there and the instructor commented it was the first clio 172 he had been in that loved to rev properly on track, he seemed very impressed with it and so are we

 

[Silent_Scone]

RS2 manifold is much better bolt on if you're just looking for fit and forget. Throttle bodies are the 'better' option but there are set backs, balancing every so often and cleaning etc

If you're already set on the RS2 I wouldn't try to persuade you otherwise, just don't expect the same results on paper as the former. The RS2 does seem to intensify the torque dip seen with 428s but just drive it hard and you'll be reet

 

[Chip-mk1]

RS2 manifold is much better bolt on if you're just looking for fit and forget. Throttle bodies are the 'better' option but there are set backs, balancing every so often and cleaning etc

If you're already set on the RS2 I wouldn't try to persuade you otherwise, just don't expect the same results on paper as the former

I view bodies as better for the track but RS2 better for the road basically.

At 50-70mph in fifth gear on A roads you dont need to change down to overtake with an RS2, you can float past on torque alone, where as on bodies you need to change down a cog or two. Ultimately bodies are better for performance but if you want a 172 as a kind of small luxury car the Rs2 suits it really well, I can see why so many trophy owners seem to be going for them, it just finishes the car off as it should have been in the first place, bodies are great at high rpm but dont give the same low rpm improvements that the rs2 does.

Purely a track car or if you are constantly thrashing your car on the road though then bodies win hands down as you wont care about low end torque or economy etc.

Very much a personal choice based on how you drive, I think at 21 I would have wanted bodies in preference on a road car as I drove like a nob the whole time, but these days (at 37) I really enjoy our phase 2 as a "nice" car rather than a thrashy one, its great for effortless drives on long journeys etc and the RS2 compliments that side of it far better than bodies do.

 

[Silent_Scone]

No problem with low end torque on bodies if it's mapped well

 

[Chip-mk1]

No problem with low end torque on bodies if it's mapped well

Well I have mapped several 172s on bodies and none of them pulled as well at 2-3K as when I mapped the Rs2 on our phase 2.

Lots of RS2 cars make 150lbft as soon as 3Krpm, and 140 as soon as 2500rpm, where as with bodies you are looking at nearer 4K instead for 150lbft of torque, which in fifth gear is gettin on for 90 odd miles an hour before it really starts to want to pull.
With bodies you'll match the standard inlet at low rpm, but you wont match what an RS2 can do down there IME

Plus TBH bodies are a waste without cams really as you'll only gain a few more BHP than you do with an RS2 for all that extra hassle, so most bodies cars realistically will have cams as well which exagerates the lack of bottom end torque.

Does depend a bit on bodies length of course, if you are prepared to lose the slam panel and put it on bonnet pins (not ideal on a road car IMHO) then you can get closer, but even then Ive yet to see a bodies car that can compete at low rpm with a good RS2 one for the same spec engine.

 

[Silent_Scone]

You still get plenty enough low down grunt for it to be far noticeable is all I'm saying, not disputing what you're saying mate. Shows it pretty plainly if you compare

 

[Chip-mk1]

I cant comment on the exact values on that graph specifically as im not familiar with TDF's rollers TBH, that doesnt marry up with what Ive seen from cars on rollers I am familiar with though TBH so I wonder if perhaps there is a bit of a difference in readings, but even on that graph its still making nowhere near its peak torque figure at the bottom end, its very much only from 4K onwards it really gets going torque wise.
IIRC thats bigash's graph? So on long bodies and lost slam panel etc, which like I mentioned does mean more bottom end torque but more expensive and less practical than most of the bodies setups which people put on roadcar 172 as opposed to trackday ones, so it was more the "normal" short inlet length bodies setups I was referring to with the bottom end issues.

 

[Nick172Cup]

You still get plenty enough low down grunt for it to be far noticeable is all I'm saying, not disputing what you're saying mate. Shows it pretty plainly if you compare

That's bodies and cams Mike, bodies will make less.

I'm not discounting ITB's either in my post, I think they're a very useful if you plan on more power like cams etc. In real life terms the extra 10bhp between all the modifications really makes not a lot of difference when driving so for me the cheapest option that you feel happy with is the way to go.

 

[Silent_Scone]

That's my graph from 2 months ago, on 90mm trumpets and 428 cat cams. Can go bigger lol.


Nick, yeah I agree mate. Like I say the RS2 is a great fit and forget bit of kit, was just making a point. They are different rollers, not meant to be a direct comparison just an indication. I think the OP mentioned he had 428s or I presumed thats what he meant

 

[Chip-mk1]

That's my graph from 2 months ago, on 90mm trumpets and 428 cat cams. Can go bigger lol

Ah it looks very similar to ash's from what I recall.

Certainly a nice result, but obviously we're comparing two different spec engines on different rollers so not really a very direct comparison.

Have you managed to get the 90mm on with the slam panel (IIRC you can if you are prepared to remove the slam panel everytime you need to get the filter off?) and have you got the standard radiator still or have you had to replace that as well, again more hassle and expense not required on a "normal" bodies setup or an RS2 setup which is why I was comparing the typical shorter bodies setups rather than the longer ones.

 

[Russ_16v]

Thats Mike's own graph chip


Edit - im way too slow lol

 

[Silent_Scone]

You can fit 90s on the Jenvey kit without removing the slam panel, at least I know you can to a Ph1. Need a shorter rad for a proper filter element though.

But yes, new rad to boot and so on...More reason to not faff about, and get the RS2!

 

[Chip-mk1]

Lovely looking bay

Not the end of the world with regards to the rad, but it is an extra hassle to consider.
Shorter radiator ceratinly wouldnt bother me personally, I fitted one when I put my williams engine on bodies and it still cooled well etc (i used a polo one) but its just another thing adding to the cost and hassle with bodies especially if people are paying others to do the work (rad is only about 40 quid but fitting is likely to be far more).

Have you still got the aircon? as thats certainly a deal breaker for me as a road car if it has to go, although I realise obviously cup owners wont mind but its one of the things I love about our 172, even on trackdays its great being able to keep cool in the queue etc.

 

[Silent_Scone]

ta



I removed the air con yonks ago as the condenser was shot, so cup setup. (Although the alternator caught fire on Saturday so needs replacing lol) Radiator is from Pro Alloy, nice bit of kit I picked up for sale.
Digress/hijack lol.

RS2 for fit and forget / throttle bodies for track /noise higher top end gain. Just to add to the OP if you're ever in Surrey feel free to PM me will gladly give you a quick run in mine!

 

[Chip-mk1]

ta



I removed the air con yonks ago as the condenser was shot, so cup setup. (Although the alternator caught fire on Saturday so needs replacing lol) Radiator is from Pro Alloy, nice bit of kit I picked up for sale.
Digress/hijack lol.

RS2 for fit and forget / throttle bodies for track /noise higher top end gain. Just to add to the OP if you're ever in Surrey feel free to PM me will gladly give you a quick run in mine!

Yeah its a case of both have their plus points so depends what you want your car for.

If we didnt have other cars specifally for doing trackdays in (including one on bodies anyway) then I would certainly consider bodies for our 172 instead of the RS2 if it was then going to be used for a lot more trackdays.

 

[Jardo]

I am set on the RS2 Chip. Sounds perfect for what I want.

Yes please, I will take you up on your offer. Are you free on Sunday 27th?

Thanks for all of your input guys, this thread is certainly not over but it has made my mind up on the first step

 

[Chip-mk1]

Sadly Sunday 27th I am at a driftlimits day with the mrs.

Could do sat or sun this weekend though, although Sun would have to be early as we'll be in weston in the evening.

 

[Jardo]

I am working on Sunday during the day, Thursday evening maybe?

 

[Chip-mk1]

Im working in london on thursday but will be back in the evening, so could meet you at like 10pm or something?
There is a harvester right by junction 25 of the motorway and some dual carriageways where it would be easy to open her up a bit so could meet you in the car park there.

 

[Jardo]

I can't do Thursday evening unfortunately, you about on Sunday 3rd?

I am 99% certain on purchasing an RS2, having a good look over one of your cars would make my mind up.

 

[Chip-mk1]

Yeah I'll be at my parents place in Taunton on the 3rd working on my mk1 as its currently in their garage, will be going Weston in the evening but around anytime before that.

 

[Jardo]

Ideal, I will ping you a PM nearer the time.

Biscuits or cake?

 

[Chip-mk1]

On a diet mate, have lost 11kg in the last 8 weeks, so neither but thanks for the offer

 

[Jardo]

On a diet mate, have lost 11kg in the last 8 weeks, so neither but thanks for the offer

Air-Con delete?

Haha

 

[Chip-mk1]

Air-Con delete?

Haha

God no, im still quite fat even now, so the last thing I want is no aircon so I sweat more, LOL
I went to quite a bit of trouble fixing the aircon.

Dont want anything in return mate, just happy to give you a chance to see the difference in how the power is delivered as its a lot of money for you to spend blind after all.

 

[Jardo]

Thanks, I really appreciate it. Quite excited about seeing the delivery and the differences, I have got my coilovers at home, my RMD seats are on order.

Apart from a RARB and RC5 pads the car is totally standard, I cannot wait to see the transformation.

 

[Chip-mk1]

Most of these cars standard shocks are now minging, so the coilovers should make a big difference as even though the standard suspension was good when new, it normally isnt by now anymore!

 

[Aaron182.]

Chip your probably the man to ask,

I'm looking at an RS2 aswell. What's this camshaft aligning tool thing stoneautomotive sell aswell?

 

[-J-]

Chip your probably the man to ask,

I'm looking at an RS2 aswell. What's this camshaft aligning tool thing stoneautomotive sell aswell?

Its a cam timing tool to allow the cams to be set to run group N timing setup.

 

[Chip-mk1]

It alters the base timing of the intake cam to increase it's advance, both in the "off" position for the dephasor and also in the "on" position for it.
Also useful on throttle bodied engines.

More advance isnt always a good thing, its not that simple, but the more you increase the volumetric efficiency of the engine the more cam advance is then useful.

So the RS2 has different optimum cam timing requirements to the standard inlet manifold on the same cams.

Wether the tool James has manages to be that exact amount is of course a different question and the reality is that at certain points in the rev range it will be and at others it wont, so depending on what you personally want from an engine it might be better or worse for you.

Personally for an RS2 on standard cams I would like to see as much advance as the pistons allow on the basis that you can actually switch it back off at high RPM anyway by turning off the dephasor (not good on the standard setup but with enough advance it would be).

 

[Aaron182.]

Wow. That's a lot of jibber jabber. Read it 3 times and understand now lol. Do you run standard cams on your RS2?

 

[Chip-mk1]

Ours is currently on standard cams and unknown cam timing (I havent checked it, belts were done just prior to us getting the car and as it drives nicely as it is I have had no reason to pull it all apart)

I might fit some other cams later on when Im less busy though, and specifically after the mrs gets a different daily as the standard cams actually work really well at low rpm where she is generally driving on a day to day basis.
Longer term plan is to get rid of my ITB corsa (TBH I only got it because it was a "staff car" for a vauxhall mag I was doing a lot of articles for but ive wound down the motoring journalism now as too busy) and to use the 172 more as a trackday car so at that point I'll probably fit some hotter cams.

Although I might of course just forget all that sensible stuff and do them sooner "just because" as I quite enjoy doing stuff like that, and just hope the mrs doesnt mind too much, lol

 

[Chip-mk1]

Wow. That's a lot of jibber jabber. Read it 3 times and understand now lol. Do you run standard cams on your RS2?

To really understand inlet cam timing, picture the cylinder empty of air, and the piston drawing down to fill it up, as the piston is travelling down the pressure in the cylinder is going to be lower than in the inlet ports in the head where its drawing from (as equalisation takes time)
Once the piston reaches the bottom of the cylinder, and starts to come back up, the inlet valve is still open, and because the pressure is so much lower in the cylinder than the inlet port it means that air still continues to rush into the bore even though the piston is now coming up.

Does that make sense?

If so, then read on, if not then stop now and go back and read it and picture the pressure of the air in the two places.

Now consider that pressure in the inlet port, its NOT going to be the same as the outside world as when air is drawn from it by the engine it needs to be replaced by rushing in through the inlet manifold.

Hopefully that makes sense? that the ports will be under slight vacuum even at full throttle?

Again, go back and make sure you really understand that, if not read again, or ask for more info, as no point reading on if you dont get that bit.


Right, so if you have read this far, it means you realise that with the piston coming UP air is still entering the engine, now picture it as being at a particular point in the stroke that this equalisation occurs and that its relative to inlet port pressure.

Now lets alter the inlet manifold so that the pressure at the port in the head is actually higher, because there is less of a differential between the port and the outside world as the manifold is allowing the air to fill it more easily due to a less restrictive design.


Now what happens? It means that the cylinder will fill sooner as there is a greater pressure differential, so it means that you will now reach equilibrium in the cylinder sooner, so you want to shut the inlet valve sooner than before, this is what cam advance achieves.

As RPM increases, the VE will drop (less time for the cylinder to fill at higher rpm) so you will want less advance up there.


TBH thats all massively over simplified as it doesnt include anything which would explain why the "worse" standard inlet tends to outperform the RS2 at certain points in the rev range (its to do with gas speeds and pulses in the inlet) but hopefully its enough to understand why just rotating the same cam around can make an engine breathe better or worse for a different inlet?