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Cat 438 Camshafts



L

Laine_16v

  HBT 172 Cup
Who here has had them fitted and mapped, and what were your results please? I've not found a definitive thread about these cams yet.

I know theres a chap with a black 182, but im sure there are a few more of your out there? Seriously considering a set of these cams. WOuld like to see some graphs
 
Jonff

Jonff

Sorry this is unrelated to your question but I've been trying to reply to your P.M you for the past couple of days about the Cup brackets you asked about but can't because your inbox is full. lol
 
L

Laine_16v

  HBT 172 Cup
Well not quite the response i was after! So i decided to buy a set, i'll let you know how i get on at the end of January :)
 
C

Chip-mk1

  182/RS2/ Turbo/Mk1
More to life than just catcams
smiley1.gif


I've got a 172 on bodies and copies of the C+B camshafts to map soon and will take it to surrey rolling road after so should have some figures for those which are another option you might want to consider?

They've done over 200 on an RS2 manifold, cant recall anyone i know using them on the standard inlet but im sure people will have done if you search.

And thats without it being on your "freak" engine so im sure you can do better, lol
 
L

Laine_16v

  HBT 172 Cup
ITB's are nice just cant justify the outlay just yet and figured cams would be a nice stepping stone in the mean time.

I want to the car mapped because it drives poorly when cold and there is the normal Sub 4k "grunt" to unlock, and figured if its to be mapped might aswell lash some cams in at the same time to make a good difference to the way the car drives.
 
C

Chip-mk1

  182/RS2/ Turbo/Mk1
The C&B or 421 (and hence 438 as its basically the same cam just with different cam timing unless the ktec website is lieing about the specs) are about the limit of what you can run on standard pistons.

Do you have plans to go high comp with big valve cutouts, if so then wait on buying cams till then so that you can just buy one set, bit pointless buying some now for a standard engie if you are going to build a proper engine later on.
 
L

Laine_16v

  HBT 172 Cup
Chip-mk1 said:
The C&B or 421 (and hence 438 as its basically the same cam just with different cam timing unless the ktec website is lieing about the specs) are about the limit of what you can run on standard pistons.

Do you have plans to go high comp with big valve cutouts, if so then wait on buying cams till then so that you can just buy one set, bit pointless buying some now for a standard engie if you are going to build a proper engine later on.
Click to expand...

Nah no plans for a forged build, simply not worth it for a car to have some fun on country roads with 1 or 2 trackdays a year.

I had 421's on my old build with bodies, and IMO the upgrade from stock cams was not worthy. I dont know if it was due to mapping or anything else? The cam "kick" at about 3.5k with the 421's was tremendous but it tailed off too quickly for some reason (204bhp peak).

But im willing to try it all again because im stupid :D
 
Silent_Scone

Silent_Scone

  Evo 5 RS
the fact it blew up could indicate it probably wasn't in the best of health? ;) Might be worth a retry..204 is a fairly weird figure for 421s is it not? Should be a few up on that. Mine was down on compression and made 204 with 428s
 
C

Chip-mk1

  182/RS2/ Turbo/Mk1
The problem with the F4R is it varies more than any other engine I know of for supposedly "the same" spec and massively different results even on a trustworthy set of rollers like Surrey Rolling Road (they arent tuners, just rollers so have utterly no interest in providing high figures or anything as they just charge for the time you are on them not for any work done as its not them doing the work)

The production tolerances must be horrific that some can fall 15 bhp short of others!

You really need to look at before and after on the same engine to draw any conclusions.

If the 204bhp was from an engine that only did 160bhp standard like some of them seem to, thats actually a pretty massive gain! If it was from a 186bhp freak engine, then its not good at all.

Mike from MWM has an engine that did 197bhp on standard cams and just an RS2 with nothing else for example, but I'll be happy if ours gets within 15bhp of that as it was only 169bhp before with matched inlets and an exhaust and probably would have been under 165 to start with.
 
C

Chip-mk1

  182/RS2/ Turbo/Mk1
Valves tend to work fine until right before they fail normally, so I doubt that lost you power TBH

Cheap valves never a good idea, id sooner use secondhand standards TBH


That graph appears to limit at 7300rpm? But you just said it failed at 7500rpm?
What was the actual limiter set to?

Cause its quite possible the roller sync was set wrong.
 
Silent_Scone

Silent_Scone

  Evo 5 RS
No but you've pretty much just worked it out for yourself lol

Personally I think 421s are still a good shout, like Laine though I'm interested to see some graphs and feedback for these new cams.
 
L

Laine_16v

  HBT 172 Cup
When mapped it was soft 7250, hard 7350.

About a week later i then decided to raise it to 7500rpm and then about 5 minutes after that i was sat at the side of the road in a cloud of smoke lol, the extra 150rpm must have just pushed the valves past their fatigue limit
 
L

Laine_16v

  HBT 172 Cup
Silent_Scone said:
No but you've pretty much just worked it out for yourself lol

Personally I think 421s are still a good shout, like Laine though I'm interested to see some graphs and feedback for these new cams.
Click to expand...

Yeah as soon as i've had it mapped ill have it posted up, was on RR'd at Ktec in december so i've got a great base to compare the results to.

I bought the cams this lunch time, just need to order a belt kit e.t.c then think ill book for mapping late Jan (if they arent too busy!)
 
C

Chip-mk1

  182/RS2/ Turbo/Mk1
The "new" cams have lobes which (assuming ktec arent lieing on their website) are:
Same lift as 421
same duration at 1mm as 421
same differential between lift at .1mm and 1mm

If they are the same total lift, the same duration from 1mm onwards and the shape of the ramp is the same (as implied by the two different duration figures at different lift both still being the same) they they must just be exactly the same or incedibally similar lobes but with a different timing centreline.
So if they are different in anyway other than LCA, it must be a bloody small difference!

RS Tuning are of that opinion too I know.

In fact the only person I have seen say that they are different in any other way than a slight timing offset is sideways danny, and he cant actually say how they are different he just thinks they are despite all the figures being the same apparently, so Ktec marketting obviously works well on him or he knows they are lieing on their website about the specs.


Will be interesting to see how you get on, 421s normally work well for most people, so I would think the 438 should do too given that they are clearly nearly identical.
 
L

Laine_16v

  HBT 172 Cup
i don't really understand deep technicalitys of camshaft profiles and their effects entirely. But it's clear their is to much overlap on 421's for the stock ECU to keep up with the plenum pulsing. I would have a very good guess the camshafts are identical accept one is "twisted" to close the overlap at idle and that would be all
 
C

Chip-mk1

  182/RS2/ Turbo/Mk1
Laine_16v said:
i don't really understand deep technicalitys of camshaft profiles and their effects entirely. But it's clear their is to much overlap on 421's for the stock ECU to keep up with the plenum pulsing. I would have a very good guess the camshafts are identical accept one is "twisted" to close the overlap at idle and that would be all
Click to expand...

Yes mate, thats what the LCA (lobe centreline angle) I referred to actually means, how they are dialled in relative to each other in order to alter the amount of overlap.
 
Jonny1*2

Jonny1*2

  Golf GTD Mk7
Silent_Scone said:
the fact it blew up could indicate it probably wasn't in the best of health? ;) Might be worth a retry..204 is a fairly weird figure for 421s is it not? Should be a few up on that. Mine was down on compression and made 204 with 428s
Click to expand...

You would expect a little more on ITB's and cams, so the engine might not have been healthy. As evidence showed a few months back ;)
 
C

Chip-mk1

  182/RS2/ Turbo/Mk1
If you pay for your car to be mapped the meggy ones are a good investment before it goes for mapping in the first place just to ensure that you dont max them out and end up wasting some of the mapping time when you have to redo it with the new injectors later on.
 
Silent_Scone

Silent_Scone

  Evo 5 RS
I was always under the impression the injectors maxed out around 215 ish..don't get me wrong I'm sure it would be pushing it...
 
C

Chip-mk1

  182/RS2/ Turbo/Mk1
519 Automotive said:
to how much fuel the injectors can deliver? I think not
Click to expand...


Flol!
Jesus Christ at you missing the point he is making by that much.

I think you should stick to changing cambelts and spinning on oil filters mate.

Cannot believe you don't realise something as fundamental about tuning as that an increase in compression improves the BSFC (google it, lol) of an engine at high rpm!

The injectors don't have to flow more fuel and the engine doesn't have to flow more air to see a gain in power when you are improving the efficiency of the engine.
Instead of the burn happening very slowly due to the dynamic compression of the engine being so much lower at high rpm, the burn speed increases due to the more densely packed molecules in the smaller space now present above the piston on the high comp pistons. This means that more of the energy is released while it can still be used to push the piston usefully down the bore (around 15 degrees atdc is generally where engines are most efficient) rather than just turning into heat where it is burning still once the piston is much further down the bore and expanding gasses are no longer causing a significant pressure on it.

It's blatantly obvious that in such circumstances you'll be able to yield more power from the same maxed out fuel flow.
 
D

Dan519

  DON'T SEND ME PM'S!!
I think you should stick to pissing off migweb and passionford with your boring waffle, c'est la vie.
 
C

Chip-mk1

  182/RS2/ Turbo/Mk1
I remember the thick kids in chemistry and physics always thought the teacher was waffling cause they didn't understand it.

Guess you didn't get many good grades at school Danny. Lol
 
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