vr6 cams

[Philmo 0]

I have a lot of scepticism for those 263 power gains results, and let me explain why - the headline figure of 26bhp gain by fitting just the 263’s is all well and good, and indeed proven on a set of rollers, but the scientific comparison isn’t quite there in my opinion. The headline figure gains are only applicable when you are only changing one variable at a time – so the question is, was the prior engine output figure of circa 190 from a standard ecu map or one that had been previously optimised? (I am leaving out the other part of the discussion, regarding torque curves and area under the graph)

The same obviously applies to the 268 cams. If I had a set of 263’s available, I would be able to test these out on my own engine, power run with a mapped 268 setup, and then again with a mapped 263 setup, but as I don’t, I can’t, pity!

 

I’m sure that I have asked this question before, but there was no answer to my recollection, be nice to see some concrete answers

For the sake of clarity :

VAG-hag's base line of 192 bhp was for a completely boggo OE setup [inc mapping] and the results previously reported followed cam & follower only change. The 221bhp figure resulted from filterless open inlet.

[NormanCoal 0]

so in this case the engine had been previously been mapped to 192 as standard component engine - ie, when the cams went in, that was the only change?

[Philmo 0]

so in this case the engine had been previously been mapped to 192 as standard component engine - ie, when the cams went in, that was the only change?

Sorry - No!

The ecu had standard OE maps prior to cam change. 192 was the found output prior to mods.

The ecu maps were optimised following SP263 cam installation to make best use of the new flow regime.

[NormanCoal 0]

I was hoping that wasnt going to be the case, as it stands, the gains are quantifiable in that engine post cam installation, but scientifically the cams can't have the whole gain attributed to them....if I can find a pair of 263's at a reasonable price, then I'll see about getting some power figures from the same engine on the same day

[Kevin Bacon 5]

I have a lot of scepticism for those 263 power gains results, and let me explain why - the headline figure of 26bhp gain by fitting just the 263’s is all well and good, and indeed proven on a set of rollers, but the scientific comparison isn’t quite there in my opinion. The headline figure gains are only applicable when you are only changing one variable at a time – so the question is, was the prior engine output figure of circa 190 from a standard ecu map or one that had been previously optimised? (I am leaving out the other part of the discussion, regarding torque curves and area under the graph)

The same obviously applies to the 268 cams. If I had a set of 263’s available, I would be able to test these out on my own engine, power run with a mapped 268 setup, and then again with a mapped 263 setup, but as I don’t, I can’t, pity!

 

I’m sure that I have asked this question before, but there was no answer to my recollection, be nice to see some concrete answers

 

That hasn't really explained anything though, it just compounds what we already know. Why not share with us the scientific reasoning to support your sceptism and then can judge for ourselves whether or not to agree with you.

 

I guess you must mean the power gains being unrealistic for the amount of extra air / fuel the cams allow into the cylinders? If you look at any of the popular American 115 degree lobe centred, 11+mm lift cams (Schimmel 263, Autotech 262, DSR256 etc etc), they all seem to give good results and 90% of users report tangible gains which they can "feel", so I don't see the purpose of this fly in the ointment post tbh. It's not like people are losing power, the plots speak for themselves.

 

The headline figure gains are only applicable when you are only changing one variable at a time

 

Adding more fuel and timing to extra air counts as one change in my book. You can't exactly bolt a turbo on as 1 variable and dyno it without the corresponding hardware and electrical changes to go with it.

 

You get a lot of people questioning Dyno figures, but they never have the opposing evidence to back up the dispute.

[plateletboy 0]

Doesn't NormanCoal just want to know what power figures a standard VR6 makes after a remap vs. a remap AND 263's..?!?

 

pb

[NormanCoal 0]

I have a lot of scepticism for those 263 power gains results, and let me explain why - the headline figure of 26bhp gain by fitting just the 263’s is all well and good, and indeed proven on a set of rollers, but the scientific comparison isn’t quite there in my opinion. The headline figure gains are only applicable when you are only changing one variable at a time – so the question is, was the prior engine output figure of circa 190 from a standard ecu map or one that had been previously optimised? (I am leaving out the other part of the discussion, regarding torque curves and area under the graph)

The same obviously applies to the 268 cams. If I had a set of 263’s available, I would be able to test these out on my own engine, power run with a mapped 268 setup, and then again with a mapped 263 setup, but as I don’t, I can’t, pity!

 

I’m sure that I have asked this question before, but there was no answer to my recollection, be nice to see some concrete answers

 

That hasn't really explained anything though, it just compounds what we already know. Why not share with us the scientific reasoning to support your sceptism and then can judge for ourselves whether or not to agree with you.

 

I guess you must mean the power gains being unrealistic for the amount of extra air / fuel the cams allow into the cylinders? If you look at any of the popular American 115 degree lobe centred, 11+mm lift cams (Schimmel 263, Autotech 262, DSR256 etc etc), they all seem to give good results and 90% of users report tangible gains which they can "feel", so I don't see the purpose of this fly in the ointment post tbh. It's not like people are losing power, the plots speak for themselves.

 

The headline figure gains are only applicable when you are only changing one variable at a time

 

Adding more fuel and timing to extra air counts as one change in my book. You can't exactly bolt a turbo on as 1 variable and dyno it without the corresponding hardware and electrical changes to go with it.

 

You get a lot of people questioning Dyno figures, but they never have the opposing evidence to back up the dispute.

 

 

If you have read what I have written, I'm not questionning the dyno results, they are what they are.

 

What I am saying specifically, is the following

 

On any given engine, for a single modification to be atttributed with X power gain, then a comparison must be made with that single change. In this case, I have not seen any figures to suggest that the 263 cams ALONE are capable of giving x horsepower. That means that there are no figures to show a standard component engine once having being optimised (or mapped) giving a horsepower figure of X, and then once a single modification has been made, the car was remapped and figure Y was acheived.

 

The crux of what I am asking is that ever since these 263 cams have come to the fore, they have magically claimed to be better than the 268 grinds that used to be popular before - they may well be better, but I'd like to see some results based on the above.

[VAG-hag 0]

From memory my car had at least one "run" on the rollers before mapping & showed a good improvement..... i dont have the "before map with 263" power graphs though. :?

[NormanCoal 0]

From memory my car had at least one "run" on the rollers before mapping & showed a good improvement..... i dont have the "before map with 263" power graphs though. :?

 

Dont get me wrong, the gains that you've got with your engine are very good, the horsepower figures are excellent (this is not about your engine or the power its got), I'd just like to know what the facts are (and that goes for the 268's as well)

[Philmo 0]

I'm gobsmacked that there is an issue here.

I understand Normancoal likes to see separate attribution of gains to cam change and re-mapping, but why?

The full benefit of the cams can't be seen until the maps have been reviewed/adjusted to suit the new airflow regime.

Surely with any mech/elec change you follow the mod with optimisation of the control system in order to realise the gains potentially available.

To separate the two stages of development is a little over-academic! [imho] :shrug:

[Philmo 0]

From memory my car had at least one "run" on the rollers before mapping & showed a good improvement..... i dont have the "before map with 263" power graphs though. :?

 

Vince probably still has graph, post cam change, pre remap though. :)

[greasegriff 0]

I'm gobsmacked that there is an issue here.

I understand Normancoal likes to see separate attribution of gains to cam change and re-mapping, but why?

The full benefit of the cams can't be seen until the maps have been reviewed/adjusted to suit the new airflow regime.

Surely with any mech/elec change you follow the mod with optimisation of the control system in order to realise the gains potentially available.

To separate the two stages of development is a little over-academic! [imho] :shrug:

 

Agreed. It's like changing your tyres and then reviewing them while they're flat - makes no sense. The two stages (new cams and re-map / new tyres and inflating them!) go hand-in-hand. Getting me some 263's soon and hopefully off up to Stealth to get them fitted (they don't know that mind!) so will try and get the necessary pointless charts then. Also getting some new tyres but on my 17's instead of 15's - not sure if my review would be accurate though as there are two variables in the equation :D

[VAG-hag 0]

^^^

 

Im sure you will like them mate... Vince n crew can prob fit them with thier eyes shut now!! :D

[87 Jetta 16v 0]

I'm gobsmacked that there is an issue here.

I understand Normancoal likes to see separate attribution of gains to cam change and re-mapping, but why?

The full benefit of the cams can't be seen until the maps have been reviewed/adjusted to suit the new airflow regime.

Surely with any mech/elec change you follow the mod with optimisation of the control system in order to realise the gains potentially available.

To separate the two stages of development is a little over-academic! [imho] :shrug:

 

Agreed. It's like changing your tyres and then reviewing them while they're flat - makes no sense. The two stages (new cams and re-map / new tyres and inflating them!) go hand-in-hand. Getting me some 263's soon and hopefully off up to Stealth to get them fitted (they don't know that mind!) so will try and get the necessary pointless charts then. Also getting some new tyres but on my 17's instead of 15's - not sure if my review would be accurate though as there are two variables in the equation :D

 

I would disagree, what Norman is trying to ask (I think) is, what gains do you get from changing certain components (in this case cams). Yes, you need to re-map to quantify the true impact of these changes, but the whole gain will almost certainly not be due to just the cam change.

 

For example, take any engine that is incorrectly set up and put it on the dyno (baseline figure - say 125 bhp for arguments sake), put some new cams in and set up the fuelling and ignition and you have a new number (modified number - say 175 bhp) did you just get 50bhp from the cams? No you didn't, you got some gains from the cams, and some from the setup.

 

To accurately state an increase from a certain modification you need an optimised baseline figure in the original mechanical state. In this example, the original cams but with the ignition and fuelling correctly calibrated. When you have this, then change the cams and re-optimise the ignition and fuelling and you will get a true gain / loss number for a certain modification. Simple.

 

What Norman is also driving at (I think) is that the original VW mapping is not 100% optimised for a standard setup. I would like to see true gain or loss figures for individual modifications, but as with anything, it costs time and money to quantify accurately.

[vornwend 0]

I think this may be a futile and possibly expensive exercise because I think we would need Vince to do the following:

 

1. Dyno an un-modded VR6

2. Re-map the above & dyno

3. Re-set to 1

4. Add cams & Dyno

5. Re map & Dyno

 

All would need doing on the same day with the same car and even then would unlikley to be representative as every engine is different (at least I think that what Vince and others have said).

 

The best approximation we would have of the difference between re-map and cams would be to use some results comparing 2 with 4 and 5 but even then I suspect there might be reasons why the re-maps (at 2 and 5) were not strictly comparable. Then we would have to do the same for other cam sizes. I'm now losing interest........

[Leonard 0]

I have never seen a std VR remapped to more than 205bhp.

 

So I think 205 as a very generous control would be sufficient. So still very good gains to be had by just fitting the 263's.

 

Anyone got a dyno of the 268's in their car with other minor mods ie exhaust filter?

 

Matt

[87 Jetta 16v 0]

I think this may be a futile and possibly expensive exercise because I think we would need Vince to do the following:

 

1. Dyno an un-modded VR6

2. Re-map the above & dyno

3. Re-set to 1

4. Add cams & Dyno

5. Re map & Dyno

 

All would need doing on the same day with the same car and even then would unlikley to be representative as every engine is different (at least I think that what Vince and others have said).

 

The best approximation we would have of the difference between re-map and cams would be to use some results comparing 2 with 4 and 5 but even then I suspect there might be reasons why the re-maps (at 2 and 5) were not strictly comparable. Then we would have to do the same for other cam sizes. I'm now losing interest........

 

Just 2 and 5 would suffice. People want an optimised set up (for numerous reasons) regardless of mechanical specification. Have a standard set mapped then dyno'd, then replace and have a replacement set mapped and dyno'd. Simple, comparing optimised set-up with optimised set-up. :D

[dukest 0]

I have never seen a std VR remapped to more than 205bhp.

 

So I think 205 as a very generous control would be sufficient. So still very good gains to be had by just fitting the 263's.

 

Anyone got a dyno of the 268's in their car with other minor mods ie exhaust filter?

 

Matt

 

I had the 268s in mine for a few weeks before it was then schricked and mapped. Definitely felt the difference as it was racing up the revs faster once higher in the range. Unfortunately i had a crank sensor wiring fault at the time so didn't get a decent dyno run with just the cams. My results with cams and a shrick are in my sig. However, given that the shrick doesnt do masses for your top end power compared with what it does for the torque i would say that 10-15 bhp from well mapped 268s is what you might hope for. in combination with the shrick you'd hope to have +15-20 bhp from your standard 190-195. (all other things the same...)

 

So, it seems that the 263s are good on their own but the schrick, although expensive, does a lot more for the low down torque and so the combination of that and 268s is a bit better than the 263s on their own. That said, i'm still curious about 263s plus schrick so thats why i'll get round to testing them later in the year :)

 

John

[Leonard 0]

That said, i'm still curious about 263s plus schrick so thats why i'll get round to testing them later in the year :)

 

John

 

Well hopefully come June/July time I will ask Vince to stick my 263's and VSR on and remap. So I will be able to let you know! :grin:

 

Oh and I have a BMC as well so should be a good benchmark for you.

[Toad 0]

I've fitted 3 sets of these cams now, and have looked into the profiles, compared the duration and lift to the standard and the 268 cams, and generally thought about mine, still unfitted in my boot.

 

Unfortunately I only have access to the graph comparing the 268s with standard at the moment. The rest of the data and the spreadsheet behind it is at home on my laptop.

 

What I have worked out is that the 263s have increased lift over the standard cams (similar to the 268s) and have increased duration 240 (I think for standard) vs 263 degrees. The lobe centres are the same as the 268s as far as I remember, so there actually is increased overlap over standard.

 

Having driven and riden in a few cars with these fitted (unmapped) I know that the noise is different for a start, and the pull from 3k to 4.5k feels stronger, however the car feels completely standard otherwise and the idle is rock solid. I have had very little experience of 268 cams which I could really compare them too though.

 

[VAG-hag 0]

i'm still curious about 263s plus schrick

 

John

 

Me too John!! please let me know when they are in!!

[87 Jetta 16v 0]

I've fitted 3 sets of these cams now, and have looked into the profiles, compared the duration and lift to the standard and the 268 cams, and generally thought about mine, still unfitted in my boot.

 

Unfortunately I only have access to the graph comparing the 268s with standard at the moment. The rest of the data and the spreadsheet behind it is at home on my laptop.

 

What I have worked out is that the 263s have increased lift over the standard cams (similar to the 268s) and have increased duration 240 (I think for standard) vs 263 degrees. The lobe centres are the same as the 268s as far as I remember, so there actually is increased overlap over standard.

 

Having driven and riden in a few cars with these fitted (unmapped) I know that the noise is different for a start, and the pull from 3k to 4.5k feels stronger, however the car feels completely standard otherwise and the idle is rock solid. I have had very little experience of 268 cams which I could really compare them too though.

 

 

That is more like it, a cam map. What you need now is a cam map for the 263's overlaid on the same graph so you can get a better idea of what these cams are doing for duration and lift at various points in the valve event. Camshafts, as with many other things are not all about headline figures and an accurate cam map is VERY helpful in determining the power potential of a set of cams.

[Philmo 0]

Hey Tom

You'ld put anything on a thread if it reminded you of :

a)Sex

b)postal excrement

c)fast food! :lol:

[Philmo 0]

i'm still curious about 263s plus schrick

 

John

 

Me too John!! please let me know when they are in!!

 

Hey John - you must be in best position to put all of us out of our misery!

Please don't forget to capture the 268+Schrick curves before the 263+Schrick curves. [both post re-mapping - of course!]

[emax 0]

Having driven and riden in a few cars with these fitted (unmapped) I know that the noise is different for a start, and the pull from 3k to 4.5k feels stronger, however the car feels completely standard otherwise and the idle is rock solid. I have had very little experience of 268 cams which I could really compare them too though.

 

Does the VR sound different in a good or bad way with the 263's? I've still got a set of these in their box from the first GB but haven't fitted them yet. I don't really have the cash for that just now.