JMS RS2 Extra?

[Adey.]

evening all, i have had a search and cant find the info or the pictures i am looking for.

Has any one here fitted and ran the RS2 Extra with the longer runners? pics would be great if possible. I run an rs2 on my trophy and am looking for a few more bits to improve it before i get a full remap. The Extra from what i have read gives a little more top end but im unsure as its hard to troll through all the threads that come up when typing in RS2 or JMS lol. I am also planning to run 197 cams if i can find a set if not ill try out the group n timing on the stock cams. Pics info and dyno printouts would be great

cheers

adey

 

[daveski]

Nick172cup had the extra

 

[Adey.]

@Nick172Cup

 

[Nick172Cup]

Yeah I had 50mm Jenvey ITB extensions fitted to mine, they may need tapering to your inlet currently depending on what design your RS2 is.

You'll have to remove the aircon, slam panel with an aerocatched bonnet, cup rad with a slimline rad fitted to it to get the extra 50mm extensions connected to the RS2.

Mine gained 4bhp and 8lb/ft of torque without any additional mapping, the torque being the most noticeable for sure! Getting someone to play with the timing on STANDARD CAMS is the way to go imo, the 197 cams lose you a lot of torque for a couple of horsepower which isn't a benefit. GroupN timing's on these would be the way to go, the rumours of a guy in France with a standard length RS2 with said timing making 200+bhp and great torque figures seems to more true than not. If I had one I'd be taking the time to prove that this method works or if not finding good results for them, as people seem to not want to bother.

I don't have any pictures I'm afraid as I'm on my iPad, search my first cup project thread for pictures and dyno graphs as there's loads there.

Cheers
Nick

 

[Adey.]

excellent, cheers for the info buddy. have been in contact with james stone this eve and he thinks he has a set of extensions that i can purchase, WIN.

Already switched to the cup alt setup after fitting the rs2 as i didnt like how close it all was, along with a polo rad and slimline fan. Bonnet pins going on this weekend. With some luck i should have a cad drawing knocked up for a group n timing horseshoe in the next week or 2.

I will indeed take a look at your build. thanks for poping on and posting.

 

[-J-]

If you do want to go 197 cammed I've got a set knocking about spare.

 

[Adey.]

my rs2 looks different to yours nick? was yours an early development one? mine has one piece inlet yours looks like its made of 2 minus the 50mm extenders

 

[chaski]

@Dan@SJM had an RS2 with 197 cams that made 200bhp, he might have some useful input for you.

 

[bozothenutter]

Following this...more interested on i creasing the torque though.
Does the curve stay nice and flat as per the normal RS2?

Any info on the tapering, how and who?

 

[Nick172Cup]

@Adeyspec -

Yeah that was the early one, however I had a revised set also which I should still have pictures for I believe?

@bozothenutter -

The torque stays similar to standard length if a tad more up to 3.5k, then it makes the more torque I was saying about from then on and holds it reasonably well to the limiter. Graphs should be in project thread as said, they'll be back to back due to comparing.

@chaski -

Dan may well of made 200bhp, but only made 145lb/ft of torque peak. Whereas mine made a minimum of 145-150lb/ft torque and peaked at near 160lb/ft. 15lb/ft of torque is a big difference in comparison to 4-5bhp peak.

Plus mine didn't have any extra timing changes and the 197 cams did.

Nick

 

[bozothenutter]

@Nick172Cup
Any link to said thread?
Can't find sh*t on the new forum.....sorry

 

[Adey.]

I'm sure the ones I get from James will be correct. I will have a before and after on the same dyno after fitting so should be a good show of what it does. Longs it's more under the line I'm happy. Will keep this updated though. Defo drives a lot better, more go from lower in the revs and seems to really pull right to the limit

 

[bozothenutter]

Don't pull to the limit, as I understand it an RS2 on a unmapped car leans out a lot in the upper rev ranges.
Might cause damage?

 

[Adey.]

i have a mapped ecu buddy :up:

 

[masekwm]

I was interested in the set up you bought, but disregarded the ECU, is it safe to use as it isn't tuned to your engines characteristics? The fuel system, engine condition, etc?

 

[Adey.]

Its close enough for now, but thats why im doing a few more things then getting it fully mapped up. Plenty of people fit ported inlets, cams, air filters and full exhausts with no remaps on the stock ecu with no ill effect. i will be plotting afr's on the next dyno runs though so it wil be on the graph.

 

[NorthloopCup]

evening all, i have had a search and cant find the info or the pictures i am looking for.

Has any one here fitted and ran the RS2 Extra with the longer runners? pics would be great if possible. I run an rs2 on my trophy and am looking for a few more bits to improve it before i get a full remap. The Extra from what i have read gives a little more top end but im unsure as its hard to troll through all the threads that come up when typing in RS2 or JMS lol. I am also planning to run 197 cams if i can find a set if not ill try out the group n timing on the stock cams. Pics info and dyno printouts would be great

cheers

adey

I run full Grp n cam timing on a standard inlet on my cup and it makes a really noticeable difference to the torque delivery. It's rpm limit is set to just under 8k and it'll happily pull round to that as well. It's on a genuine Grp n Renault ecu as well.

Just an FYI mate for if you were thinking of fitting 197 cams and was unsure.

 

[chaski]

@Nick172Cup as I alluded to in my post I have neither the expertise not experience to comment. I simply know/knew Dan has knowledge and experience that is relevant to this discussion and thought he may be interested in contributing. As far as I know, getting 200bhp was deliberately just that, an exercise in getting the figure. That suggests to me he knows his onions when it comes to playing with the rs2. This topic is well beyond my personal knowledge and I'm not pretending for a second that I personally have any valuable input.

 

[Dan@SJM]

Nick, mine wasn't a particularly torquey engine before the rs2. It certainly didn't loose any torque.

 

[bozothenutter]

Tech question:
If you have an RS2 and wnted the extended bits...how would you tapwr them?
Isn't the taper matched from the trumpets to the intakeport?
Ie if you would continue the taper the resulting opening would be bigger than the trumpet?

 

[NorthloopCup]

Tech question:
If you have an RS2 and wnted the extended bits...how would you tapwr them?
Isn't the taper matched from the trumpets to the intakeport?
Ie if you would continue the taper the resulting opening would be bigger than the trumpet?

Depends how much of a taper it needs. I'd use a carbide burr in a die grinder or high speed drill and open it out. I'd go about 50-70% of the way up the extension and keep checking your not taking too much out with a internal caliper. Then I'd use an 80 grit sanding drum to finish off the surface and finish off the taper. Takes a lot of time and a steady hand though mate. You may also struggle to do it as there's not enough meat inside the rs2 trumpets to allow you to match the taper. You may have to leave them parallel or get the 40mm id ones and open them out to the 45mm of the rs2 trumpets (that's what mine were anyway) as that's just a simple machine shop job. Jenvey may even do it for you tbh for additional cost.

You won't notice enough of a difference if you left them parallel as well btw. You are correct though, the taper *should* be matched to the length of the intake runner to the mouth of the valve.

 

[bozothenutter]

Thanks mate, so to be perfect..you'd need a whole new manifold really.

 

[Ph1 Tom]

@Adeyspec
The runner extensions are the standard jenvey SF type extensions, you can get straight and curved ones.

I have an alternative method of doing it which would gain you more than 50mm.

I also have some plates so you can keep the grill in place but remove the slam panel and bonnet catch.

 

[NorthloopCup]

Thanks mate, so to be perfect..you'd need a whole new manifold really.

Honestly mate you'll never tell the difference with parallel extensions going on to the tapered lower half of the manifold

 

[Adey.]

@Adeyspec
The runner extensions are the standard jenvey SF type extensions, you can get straight and curved ones.

I have an alternative method of doing it which would gain you more than 50mm.

I also have some plates so you can keep the grill in place but remove the slam panel and bonnet catch.

the set i have coming from James Stone should be here tuesday, but would be good to see your alternative? slam panel out and aero catches already fitted for extra space in anticipation of the longer inlet

 

[Ph1 Tom]

It gives you a lot more length than straight extensions because the angle (see Nick's engine bay) pushes the inlet into the bonnet. Changing the angle and moving it towards the front of the car gives you much more space. For example my total inlet tract length is 380mm whereas the maximum with straight adapters is 330mm, and mine is a ph1, if it was a ph2 there's scope for another 10mm so 390mm vs 330mm. The next step for me is to come up with some kind of intake/airbox and do away with the sausage filter, then I could break 400mm I reckon.

The plates I have are so you can keep the top of the grill. Its a shame I had to loose mine but I had no choice as I have ITBs and it would affect air flow. Imo it looks s**t without and keeping the top of the grill keeps the car looking tidy. These are the plates the allow that.

 

[NorthloopCup]

You know what airbox to get @Ph1 Tom :smile:

 

[Ph1 Tom]

You know what airbox to get @Ph1 Tom :smile:

Indeed, they are a thing of composite beauty! Although I have considered making my own to suit the ph1 specifically and take air from the ph1 front grill. I need to have a proper think about it.

 

[NorthloopCup]

Indeed, they are a thing of composite beauty! Although I have considered making my own to suit the ph1 specifically and take air from the ph1 front grill. I need to have a proper think about it.

Ain't they just! Works with ph1 or ph2 as well.

 

[bozothenutter]

Details chaps!... .details!

 

[NorthloopCup]

Here you go @bozothenutter

 

[bozothenutter]

A thing of beauty!
Who where why what?

 

[NorthloopCup]

mcracingsa.com mate.

 

[Adey.]

little update on this, added the extra spacers for a little more length, ran it on the dyno and even though the revs are incorrect it pulled 197bhp and quite flat torque, it recorded 145lbft at the rev limit of 7500 not the 7100 the dyno calculated with so i make that 208bhp at the rev limiter? i know every dyno is different and all should be taken with a pinch of salt but she flys so im happy. next up is the 197 cams ive just paid for a remap to suit :up:

 

[bozothenutter]

Sooo tempted to have a go at this.
How much were the spacers?

 

[Adey.]

Best to contact jenvey buddy, and measure up the bore you need. Probably looking at around 180