Timing.......FAO, MWM, Fred, Chip, 519, Birchdown

[MG cup]

I'm in the process of replacing the cambelt in my cup just now, I put in the timing tools before removal and the inlet cam was a fair bit advanced like so

Knowing enough about engines to know its safe enough the amount its been advanced, I couldn't tell you how to play with cam timing to better yourself though. My question is, do you think that could be making low down power better??


I gave the car a road test before stripping down and it felt like it went REALLY well, I never redlined it due to its tendency to snap steer over bumps. I went through the all the gears probably to about 6k in some checking g/box etc......so do you think that cam angles are beneficial? I know there's a group N timing tool with about the same degrees


[FONT=.HelveticaNeueUI]http://www.cliosport.net/forum/showthread.php?597835-Semi-GR-N-camshaft-locking-tool[/FONT]
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[FONT=.HelveticaNeueUI]Could that be making all the difference or could it just be a freaky engine. Bare in mind the compressions down on 2 cylinders too [/FONT]

 

[Dan@SJM]

Tbh that's more than likely just a garage that doesn't know what they're doing from my experience!

But I've used one of the laser tools to make my 197 cam tool as it was easy to bend to the specs I needed lol

 

[MG cup]

Yeah me too but it looks like its made a difference, exhaust cam was pap on and inlet just tweeked a little.

That's what I'm thinking about my current tool tbh, bend it to around 5-6 deg and use that for standard cams and then buy another for the race car.

 

[Dan@SJM]

I know mickpm had adjusted his inlet and said it died top end, Wishing he hadnt. I do also know cups do seem to be the fastest, Emma's for instance was the fastest stock one I'd driven. Then rolling roaded at 183!

 

[MG cup]

Well after having a good read of that thread I linked, I think I will redo these settings when I time it back up. The idle does suffer from it like has been said in there but going to give it a try and get it rolling roaded and maybe swap back come end if the year and rolling road it again.

Have you fiddled with 197 timing Dan and get good results??

 

[Dan@SJM]

Well with the 197 cams and an RS2 I've cracked 200bhp. On a 172 that wasn't particularly strong before hand. Went well but only average for these.

 

[MG cup]

Ahh I get you, I thought you had fiddled with the timing on the standard 197 engines. Its the same difference really, the two engines are very similar in design. I know MWM was given one of these group n tools, I guess it has filtered down to you through chip and that's where you lads a lads getting that little bit more from the RS2...same tool?!?!? PM if you don't want to say

 

[Dan@SJM]

Timing wise in just rs2 setups we don't change the timing atall. Myself, Lesley and mike are the only people with the 197 cams in I believe and mike advised me what the settings were as we'd worked together before. I won't say what the settings were as it was Mike who spent many hours on a dyno adjusting and mapping to see the significant gains we have bad from them, as its not my place to tbh.

 

[MG cup]

No worries, I understand that he has spent his time to fine tune it and he can make money from it so that's cool.


Can you tell me how the 197 cams compare to the 172 though, more duration, higher lift, more lap over etc etc??

How does your car idle with the rs2 and 197 cams, I'm guessing its a little rough in a trade off for better top end??

 

[Dan@SJM]

I don't know the spec if I'm honest. Idle wise, lumpy as f**k lol. But it reminds me of my old valver on 270's

 

[MG cup]

That's enough for me to be happy to keep the settings

 

[Cupman29]

Looks like you are 180deg out with the cams and it looks like your exhaust cam is not pointing perfectly into the center line of the inlet cam so to me it just looks out. You would only advance the inlet to a maximum of 7deg if you removed the dephaser surely or you would have 14deg of advance.

 

[DTM]

I had this same problem timing mine up and found after I'd set it correctly the car pulled alot better low down, and felt better 5k+ rpm onwards, I think advancing the inlet timing will only really help if you shorten the inlet manifold i.e. the RS2 or ITB's

 

[Fred@BTM]

well spotted cupman, the cams are upside down

 

[Chip-mk1]

well spotted cupman, the cams are upside down

Both upside down isnt a problem, just means its 360 degrees (crank) out in the 720 degree cycle, turn it over once more and it will be back to normal.





Its a pain there isnt a more trivial way of playing with cam timing than to keep pulling it all apart, only option is verniers really and then you lose the advance from the dephasor of course which is massively counter productive.

 

[NorthloopCup]

I know mickpm had adjusted his inlet and said it died top end, Wishing he hadnt.

That's why renault knocked the exhaust cam back a touch, to keep them alive at the top end. That's on the full grp n settings of course.
When mines alive again I will be able to give a report back as to how much it holds on as I've got the full grp n tool and the grp n ecu to match. Assuming people would be interested that is.

 

[lewvr6]

That's why renault knocked the exhaust cam back a touch, to keep them alive at the top end. That's on the full grp n settings of course.
When mines alive again I will be able to give a report back as to how much it holds on as I've got the full grp n tool and the grp n ecu to match. Assuming people would be interested that is.

Is group n tool used with an otherwise standard engine? As in internally stock, stock 172 cams etc?

 

[Chip-mk1]

Is group n tool used with an otherwise standard engine? As in internally stock, stock 172 cams etc?

Yes it was in rallying, well stock-ish as is always the case with group n, lol

 

[Thrust-Rated]

Interesting read about the group n stuff not heard of it before

 

[lewvr6]

Oh ok, interesting. So this tool, puts the cam(s) in what kind of position relative to standard, and to the crank? Inlet stays as per Renault tool and exhaust cam is retarded? Or both are adjusted?

 

[NorthloopCup]

Is group n tool used with an otherwise standard engine? As in internally stock, stock 172 cams etc?

Yes mate. All a grp n engine is in reality is a standard engine that's had the tolerances machined/adjusted to the closest/best they can be. Ie: the cams in a grp n car will have been ground as close to tolerance as possible, and gain maybe a few thou lift. Not much granted, but in terms of extracting maximum performance, as tesco say, every little helps.

My grp n ecu ups the limiter to 7.8k ish as well.

 

[NorthloopCup]

Oh ok, interesting. So this tool, puts the cam(s) in what kind of position relative to standard, and to the crank? Inlet stays as per Renault tool and exhaust cam is retarded? Or both are adjusted?

Both adjusted mate. Inlet is advanced and exhaust is retarded. And getting hold of the full grp n tool is nigh on impossible! I struck lucky and I was considering getting some reproduced as well.

 

[lewvr6]

Sounds good, be interested to hear the outcome when yours is running. Any idea how much the cams are moved? I dint think there was too much tolerance in the timing hence it being so crucial even when doing a standard timing. Obviously some room for small adjustment then providing you can measure clearence and performance to find an optimum.

 

[mark123]

I measured the angles as best I could from a pic of the group n tool. It was about 5.5 degrees advance for the inlet and 4 degrees r****d for the exhaust.

Never tried it out though.

catcam specs are here

http://www.catcams.be/800x600/prod01Alist.htm?PN55044xx.js

The FIA one is the "std" group N cam shaft I think - although the numbers don't look right to me. Too much overlap compared to the others?

 

[Andrewclio]

Does anybody know weather the cup racers used the 'group n timing tool' when timing up there engines?
Just because the parts numbers on the cams for the group n and cup racer are the same

 

[ben_r1]

FAO Chip I have Verniers on the 197 via VVT delete and find it to deliver power much smoother than standard, IMO it's beneficial on track where you can keep the revs high, no counter productive...

 

[MG cup]

Looks like you are 180deg out with the cams and it looks like your exhaust cam is not pointing perfectly into the center line of the inlet cam so to me it just looks out. You would only advance the inlet to a maximum of 7deg if you removed the dephaser surely or you would have 14deg of advance.

Well spotted, yeah your right mate. Noticed it today when I was playing around, just threw the tools in quickly before removing belt and never checked the flywheel for TDC. Inlet cam is still advanced and I think I'll so it again tbh, may even try and dial the exhaust a little too, cold get risky when the standard cams are not as tight of tolerances.

Does anybody know weather the cup racers used the 'group n timing tool' when timing up there engines?
Just because the parts numbers on the cams for the group n and cup racer are the same

Fred said he knows the guy that rebuild's them and they were standard, cup racers run sweet on idle where as this is real lumpy. I would think all the best bits were pulled out the parts bin as they make healthy power.

 

[MG cup]

Looks like you are 180deg out with the cams and it looks like your exhaust cam is not pointing perfectly into the center line of the inlet cam so to me it just looks out. You would only advance the inlet to a maximum of 7deg if you removed the dephaser surely or you would have 14deg of advance.

Both adjusted mate. Inlet is advanced and exhaust is retarded. And getting hold of the full grp n tool is nigh on impossible! I struck lucky and I was considering getting some reproduced as well.

Have you started it yet? How's the idle with the exhaust retarded?

 

[Sam@NP]

Fred said he knows the guy that rebuild's them and they were standard, cup racers run sweet on idle where as this is real lumpy. I would think all the best bits were pulled out the parts bin as they make healthy power.

Didn't cup racers have standalone?

 

[Fred@BTM]

^yup italian specialist control

 

[Chip-mk1]

FAO Chip I have Verniers on the 197 via VVT delete and find it to deliver power much smoother than standard, IMO it's beneficial on track where you can keep the revs high, no counter productive...

The vvt on the 197 allows you to map in variable advance, not having that isn't an improvement at all, if yours had it and was mapped properly to use it all it would do is gain you torque, you wouldn't lose anything. Only down side to the vvt is reliability if revving really hard and if using very high lift cams you run the risk of contact if it doesn't operate correctly. Performance wise though its all round win for the vvt

 

[Andrewclio]

Didn't cup racers have standalone?

Ye since fitting the sequential I've also used the cup race loom and ecu, was just wondering weather there was any difference to the timing in these too since they use the same cams

 

[NorthloopCup]

Have you started it yet? How's the idle with the exhaust retarded?

The idle speed is set to 1200rpm mate, so the lumpy idle isn't an issue.

 

[MG cup]

How easy would that be to change by itself on the standard ecu?

 

[Chip-mk1]

How easy would that be to change by itself on the standard ecu?

Its still a remap essentially, so still need to pull the map off, alter it, calculate checksum, reload it.
So not something you can do without a lot of equipment.

 

[MG cup]

I worried that, so by the time I do that It would have been just as easy for someone to remap it.

 

[Chip-mk1]

Well not quite as easy as they won't have to do all the rest of the cells for fuel and ignition etc. but it won't be a DIY task.

 

[MG cup]

Its going to a tuner to have its friendly MOT done, what do you think would be a good price to have the idle raised Chip?

 

[Chip-mk1]

Depends who is doing it. Not for me to quote on others behalf really. Maybe 150 quid or something like that as some sort of minimum charge would seem acceptable I guess?

 

[MG cup]

Just to give me an idea if they throw out a crazy number which I think £150 is tbh, thats 2/3's of the way to a remap.