[Mk2] [Turbo] Do uprated cams help reduce turbo lag?

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Ryan.g
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by Ryan.g »

There is no way Jims car will idle at 900rpm, already tried and its not nice but the old owner didn't want the cam timing changing to fix as they likes the sound :lol:

The way PP have set the cam timing is pretty mad but works well for power and torque. To get the car to idle better jim and loose the massive VE drop your engine has at 2k you will need to adjust the intake cam.

The intake cam is the one which creates the lumpy idle normally.

Ryan
JJ
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by JJ »

I've gone back over on the lumpy bit.. mines smoooth now !! Timed it and timed it to HKS specs.... give them the benefit of doubt !! Good heads up on the FC adjustments Ryan... if mines playing up and its not my spaz right foot... I'll use those settings ! :thumleft:
jimGTS
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by jimGTS »

Thanks Ryan.
What sort of job is it to change cam timing anyway?

I to love the sound of the car, quite different to what i've heard before, just concerned when mot comes round, maybe to loud.
Any reason why the cams are set up this way? For track/drag?

Am sure you'll agree the car drives real nice anyway.
I don't want to potentially loose a load of hp adjusting this cam. But if I can get the idle down a little, and loose the slight stuttering it's werth sacrificing I guess. Tho I still plan on cracking 400hp with the car :-)

Nice to have an informative thread, so let me know your thoughts.

Jim
Leon.
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by Leon. »

jimGTS wrote:My only concern is come mot time, they may think it's to loud as high idle.


I'd be more worried about meeting emissions mate, might want to find a friendly MOT garage if you haven't already... mine doesn't even get close!
jimGTS
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by jimGTS »

I have a phoenix power high flow sports cat welded into the apexi turbo kit Downpipe. Woo! So hopefully that will sort me out. Will need it checking tho before mot time to see my options if it doesn't pass.

But total bonus it was finding that when I got under the car and things.
Lots of phoenix power goodies!
Chris
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by Chris »

Injectors have nowt to do with poor idle, mines on 1000's and ticks over at 850rpm but I'm on stock Rev 3 cams. If lift reduces lag, then what about a set of Rev 3 N/A cams? Slightly higher lift? :-k
JJ
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by JJ »

What sort of job is it to change cam timing anyway?


Its a bit of a b1tch to sort the cam timing out whilst the engine is still in situ, but with my experience .. if you've got the HKS 272's destined for the rev 3+ engine, the optimal peak lift is usually near spot on to zero'ing the cam timing gears out ( as long as stock head gasket thickness has been retained 1.0mm Post 93, 1.2mm pre 93). Likewise with the pre 93 / Rev 1/2 engines.

Its when you've bought say 264's / 272s from the stateside but originally destined for the Rev 1/2's engine, you need to time them up as fitment to the rev 3 head at zero wont achieve optimum / HKS settings. ( Rev 3 + heads are taller ! + introducing other factors that will contribute to variance )

Thats if you're trying to acheive HKS settings for the rev 3+ :

Intake - 272 duration 10.4mm lift = 111 Degrees
Exhaust - 272 Duration 10.2mm lift = 116 Degrees

There are other lifts differences available - If your cams were destined for the Rev 3+ engine, then no matter what duration cam they are, they've been machined / calculated to an optimal phase peak at intake - 111 degrees and Exhaust - 116 deg accordingly.

Any further "benefiting adjustments" to these settings will promote improved torque /power earlier in the rpm scale or later ... which should nudge discussions to who finds the best settings for their driving styles, what they want from the engine. ie. I prefer making loads of torque and power at the top end of the rev range ( 5K+) due to the noahs ark turbocharger I have fitted.


:thumleft:
jimGTS
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by jimGTS »

Pretty sure stock rev1/2 gasket is 0.9mm.

Anyway, without having a clue what cams are on the anyway, looks like it's going to be difficult. Would even looking at the cams, tell me what they are? How good are people at identifying a set of cams if no markings?

Tbh, I love the top endness of my setup. Very different to my 301hp rev2 with the ct20b.

Am sure if I had to change cam timing, cambelt needs to be loosened, so quite a bit of work.
JJ
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by JJ »

Cambelt doesn't need to come off jim, the adjustable cam gears allows you to move the cam in situ.

Cams - cam cover off... if its a HKS cam setup, it'll have HKS stamped on it and it'll also have the part number to for identification. All depends if you want to get your hands dirty !!

Pretty sure stock rev1/2 gasket is 0.9mm


I've measured them Jim and quite a few after compression, they're 1.2mm. The wealth of junk floating around in my head mainly out of curiosity is collected back to 1994 :mrgreen: when I owned my first 3S engine and 4A and wanted to make them go faster !! :thumleft:

Tbh, I love the top endness of my setup. Very different to my 301hp rev2 with the ct20b


You've come along way Jim, I remember you buying that and ploughing the forums with questions ! :D
jimGTS
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by jimGTS »

I did do well with that car.
Without questions you never learn :-)
Did my headgasket change, arps, metal hg and all that. rev3 ecu conversion and power fc, all the bolt ons, all fitted on my driveway :-). Was a very tidy car and great to drive. Not many rev1/2s with ct20b pumping out those figs on the uk forums 301hp/290lb, 255atw.
I had purchased a td06 to go on, and got 800s. Then the rev5 came up for sale literally the week i planned to put those items on!
Very tough decision considering the 4 years I put into that rev2.

Adjustable cam gears, surely those are aftermarket? I had a look at my gears when nosing around and they looked stock. So surely belt needs to slip off and move the cam slightly (I realise the belt wouldn't need to come fully off, even more of a pita). Perhaps ive got the wrong end of the stick about adjusting.
JJ
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by JJ »

You must have adjustable cam gears if you say the cams have been "setup" for power by PP !!

May explain why ryan couldn't get it to rev any lower if you've a mix match of cams and stock cam gears....

Anyway... cant really speculate unless you're 100% they're stock and what cams you're running ... Rev 1/2's you can adjust the degree ever so slightly by moving the slip pin in a different location ( movings its position )

rev3 ecu conversion


I wrote the conversion slides that are referenced !! :mrgreen:

Not many rev1/2s with ct20b pumping out those figs on the uk forums 301hp/290lb, 255atw


Never rolled mine, but my original rev 2 setup with rev 3 ecu + Modded CT26 saw a regular 12.4* up the strip !! :-$

You need to pull your cam cover off and see whats in there !! With the correct adjustments, you maybe able to release more power !! Mine was rolled at 1.3 bar and put out 425 bhp (FW) 352 lbs :wink:
jimGTS
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by jimGTS »

JJ wrote:You must have adjustable cam gears if you say the cams have been "setup" for power by PP !!

May explain why ryan couldn't get it to rev any lower if you've a mix match of cams and stock cam gears....

Anyway... cant really speculate unless you're 100% they're stock and what cams you're running ... Rev 1/2's you can adjust the degree ever so slightly by moving the slip pin in a different location ( movings its position )

rev3 ecu conversion


I wrote the conversion slides that are referenced !! :mrgreen:

Not many rev1/2s with ct20b pumping out those figs on the uk forums 301hp/290lb, 255atw


Never rolled mine, but my original rev 2 setup with rev 3 ecu + Modded CT26 saw a regular 12.4* up the strip !! :-$

You need to pull your cam cover off and see whats in there !! With the correct adjustments, you maybe able to release more power !! Mine was rolled at 1.3 bar and put out 425 bhp (FW) 352 lbs :wink:


i personally didnt say my cams have been "setup" by PP, lol....but i guess if thats what ryan thinks, then who am i to disagree....even if not pp, i guess they must have been setup by someone.
could be a possibiltiy that the cams were just put in, and stock cam gears. wouldnt have thought that would be an issue. no diea.
the gears wernt a fancy purple colour like the hks ones....looked grey/black like stock to me....(tho i didnt remove the whole cambelt cover).

ive yet to pop the cam cover yet to have a noisey round, when i do ill take some pics.
JJ
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by JJ »

i personally didnt say my cams have been "setup" by PP, lol


Speed reading through the lines I guess #-o Combination of everyones comments !

could be a possibiltiy that the cams were just put in, and stock cam gears. wouldnt have thought that would be an issue. no diea


As mentioned in my previous post, if the cams were destined for the Rev 3+ engine, then the peak lift will happen if the cams were zero'd in.. meaning in stock location.. which means your stock cam gears are fine. Chucking them in can work.. ( other factors not considered like HG thickness, deck and head skimming etc )...I've seen many do it.. but I'm particularly anal when it comes to clearance to the follower/bucket / valvetrain... you're fitting cams to improve lift and duration.. if the clearances are miles apart, you wont benefit from them... so each valve clearance needs to be measured accordingly... A noisy valvetrain often indicates this hasn't been done.
jimGTS
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by jimGTS »

ok thanks.

not entirely sure what i should be doing now. :?
whether to just leave it, or get it reshimmed or whatever, which involves alot of work....i would asume this was done on install, as does look and sound like the engine has had a full rebuild...
but obviously you never can be sure.
(theres lots of randon jubilee clips in hard to reach places, clips on the water elbow matrix, removed tvsv etc etc)
JJ
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by JJ »

not entirely sure what i should be doing now.


When the sun comes out... or you want to bury your head in the garage... spend an afternoon taking the cam cover off... id the cams... take them through a 360 engine rotation if you can't see some markings, make a note !!

If you know and trust the history of the previous owner.. then he'll / you'll already know whats in there...
Dale_V
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by Dale_V »

cams eughh!!

it took me ages to get a decent idle out of the piper 264s, it took months of playing about with the timing from the piper spec to get it to idle to anything near decent, its now at around 900rpm, but still sounds a nice lumpy :mrgreen:
jimGTS
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by jimGTS »

JJ wrote:
not entirely sure what i should be doing now.


When the sun comes out... or you want to bury your head in the garage... spend an afternoon taking the cam cover off... id the cams... take them through a 360 engine rotation if you can't see some markings, make a note !!

If you know and trust the history of the previous owner.. then he'll / you'll already know whats in there...


previous owner.
a japman! who must of taken it to phoenix power.
thats the only info i can really give regarding previous mods.
(its only been in country 8months, ive had it for 4)

rash the importer was only told the car had basic mods when he imported it over and bought it in japan, when in uk, he opened the engine lid and found lots of goodies (check my garage)
he didnt source it for anyone in particular, just bought it and planned to sell it on when it was registered. so no real details at all.
(did come with a PP engine lid to, which the bu88er took off
:( :eye: )

when i got some time, ill pop the cover off and ill see what i find and take some pics.
3sgte
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by 3sgte »

Ryan.g wrote:

You should have rang Marc. Sounds to me like your Overrun fuel cut is cutting it to earlier so to get round this try....

On the commandor go to settings - idle/rev - Then after the rev limit, adjust the next 3 f/c values to 4000rpm. This means that under 4000rpm the Fuel overrun is not used. If this works then try adjusting your TPS.

Reason you can get round this well on the Link is because you can calibrate the TPS through the software which you cant with the PFC. But the 4000rpm trick normally gets rid of it.

Ryan


runs like poo was a bit of an exageration it is a bit jumpy but worse when you are trying to drive smooth ,i found if you drive flat out everywhere then it aint a problem :mrgreen:
i'm pretty sure the tps is setup correct as when i had idle issues on the rev3 ecu due to the cams i set it up 3 times to the book

i'll hav eto give you a ring soon mate, still got to turn the boost up :twisted:
JJ
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by JJ »

Mark, have you done those adjustments yet ??! I did it on mine last night and can confirm, the low speed driving is smoother ! :shock: Needless to say I was suprised !!

You want to see the fast a furious flames I'm getting now as well !! :shock: :mrgreen: Doesn't help I've richened the map on no load @ high rpm ! :whistle: 16 mpg anyone ??!! :mrgreen:
RyanRs
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Re: [Mk2] [Turbo] Do uprated cams help reduce turbo lag?

Post by RyanRs »

Chris wrote:Injectors have nowt to do with poor idle, mines on 1000's and ticks over at 850rpm but I'm on stock Rev 3 cams.


yes they do. like i said in my prev post, 1150's can keep a smooth idle while delivering fuel for high bhp, i believe they was designed for just this as the next size down was 1000cc (too small for some setups) but next size up was something silly like 1600 -which do give a lumpy idle.

Btw, can i ask why your pathetic Signature is magically back?
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