428 or Group N cams?

[Baal]

Well i have a doubt, how can there be a "Group N" Cam if the FIA Group N does not allow any cam change?

Also i want a cam for my Rally Clio im not sure but the group N cams seem a little bit too mild, do the 428 work mid range or is too top end for rally?

Also, do both of these cams retain the VVT?

 

[sideways danny]

420 cat cams are a waste of time on a road car, but conform to group N spec, they're optimised within standard tollerence basically.

The best cams for all round on a stock bottom end are 421s, but the standard ECU can't cope with those. 428s are good for fast road. All depends on your engine management solution. Believe all cat cams are available in "vanos delete" which is non VVT

 

[Baal]

So the Group N cam is a waste of money, what about the 428??

While ECU remapping should be no problem i dont want to go for a huge cam that will kill the car responsiveness in low RPMs, after all i have a stock transmission.

 

[Gray]

How do the 421's compare to the 428's on an other wise standard engine?

 

[Fred@BTM]

i've seen over 190bhp and 160lbs/ft with 428's

 

[Seedy172]

WOW, really?!

 

[Fred@BTM]

yeah, that's exactly what i said when we mapped it!

 

[Seedy172]

I mean, I'm not well up on these things. But I can see that's pretty impressive. Silly question, we are talking 172? What exactly is required, and what kind of cost's are involved!?

 

[sideways danny]

i've seen similar on 428s with un-modded RS inlets, standard exhaust (182) and an omex

 

[Fred@BTM]

i believe kam racing do the 428's for around £530, then you have fitting and mapping (plus cambelt change), BUT the car i'm on about (172cup) did have a few extras such as match manifolds and 182 manifold, on a normal car mid 180's would be the norm IMO

 

[Seedy172]

Looks like the right way to go tbh... never realised the matched inlets made that much of a difference though. I'm quite a way off this yet (will be aiming for somewhere 200BHP PT), but it's all good to know.

 

[Andyman]

IMO if your thinking of fitting cams on their own and expecting huge gains forget it, they are a waste of time on a near stock engine unless its stage 1 of future plans. A lot of outlay and a lot of work when theres far far better options available.

If you want to be about the 200bhp area jump straight to TB's.

Cams on their own will skirt about the mid 180's area, high to low 190's with bolt on such as inlets, 182 manifold etc etc


Iv got Pipers fitted in conjunction with a lot of other mods. The car pulls like a train really low down. I can accelerate in 5th at 1500 rpm. Acceleration is very impressive. - Also managed to get TB area levels of torque. Top end pulls ok. Down side (maybe), il tell you next week sometime (see my dephaser topic)

Cat cams 420's make just about stock. 428's seem to be the most popular all round cam but read they compromise a little bit low down the rev range and 421's come in above 5k, better for use in conjunction with TB's maybe?

 

[Baal]

IMO if your thinking of fitting cams on their own and expecting huge gains forget it, they are a waste of time on a near stock engine unless its stage 1 of future plans. A lot of outlay and a lot of work when theres far far better options available.

If you want to be about the 200bhp area jump straight to TB's.

Cams on their own will skirt about the mid 180's area, high to low 190's with bolt on such as inlets, 182 manifold etc etc


Iv got Pipers fitted in conjunction with a lot of other mods. The car pulls like a train really low down. I can accelerate in 5th at 1500 rpm. Acceleration is very impressive. - Also managed to get TB area levels of torque. Top end pulls ok. Down side (maybe), il tell you next week sometime (see my dephaser topic)

Cat cams 420's make just about stock. 428's seem to be the most popular all round cam but read they compromise a little bit low down the rev range and 421's come in above 5k, better for use in conjunction with TB's maybe?

I race in N3 (group N) so i cant use ITBs plus they are veeeery pricey, maybe in a future i will go to the A group and get ITBs.

it seems the 428s are the way to go, the 421 at 5krpm is useless for rally atleast with a standard gear box, maybe with a 6 gear clutchless Sadev it might be an option but as it is no way in hell.

 

[Andyman]

Reading about them they do seem about the only choice between gain and driveability yeah.

Not sure about other cam choices tho and what they offer

 

[Domobaby]

Iv got Pipers fitted in conjunction with a lot of other mods. The car pulls like a train really low down. I can accelerate in 5th at 1500 rpm. Acceleration is very impressive. - Also managed to get TB area levels of torque. Top end pulls ok. Down side (maybe), il tell you next week sometime (see my dephaser topic)

Are these the piper cams which give this torque characteristic. I dont like revving the nuts off the engine and an iive been trawling the forum to try and find what mods could give this.

 

[Andyman]

Not sure if its the cams, the other mods or the whole combo.

The only ''different'' extra mods it has from the usual is headwork and lightend fly

 

[Toxic#66]

I race in N3 (group N) so i cant use ITBs plus they are veeeery pricey, maybe in a future i will go to the A group and get ITBs.

it seems the 428s are the way to go, the 421 at 5krpm is useless for rally atleast with a standard gear box, maybe with a 6 gear clutchless Sadev it might be an option but as it is no way in hell.

hmm not true 421 work only after 5k range in my case 5k kick is not even there any more
My ph1 172 pulls like a train from low down (propablly because it copes with 182 exhaust manifold) and its not even fully mapped yet.
Both, mine and my mates stock 182 makes about the same top end power but on a track day when we tested our cars mine on a short straight line between corners made 68MPH when my mates 182 did only 55MPH
He was acctually impressed how the car accelerates in comparision to his car. And to be honest my ph1 is quite a budget project since its only a 182 ehxaust mani / RS stamped inlet mani / self made inlet match / 2,5" stainless steel exhaust and OEM ECU RS Tuner custom remap. it made only 178BHP and 161lbs/ft but the way it runs I cant complain (yet ) I'm tempted to buy Omex in the future in hope for the better gains from the same setup but I need someone experienced to convince me

 

[Baal]

hmm not true 421 work only after 5k range in my case 5k kick is not even there any more
My ph1 172 pulls like a train from low down (propablly because it copes with 182 exhaust manifold) and its not even fully mapped yet.
Both, mine and my mates stock 182 makes about the same top end power but on a track day when we tested our cars mine on a short straight line between corners made 68MPH when my mates 182 did only 55MPH
He was acctually impressed how the car accelerates in comparision to his car. And to be honest my ph1 is quite a budget project since its only a 182 ehxaust mani / RS stamped inlet mani / self made inlet match / 2,5" stainless steel exhaust and OEM ECU RS Tuner custom remap. it made only 178BHP and 161lbs/ft but the way it runs I cant complain (yet ) I'm tempted to buy Omex in the future in hope for the better gains from the same setup but I need someone experienced to convince me

Do you have a graph? cuz otherwise its just a "mine pulls like a train" statement which doesnt says much.

 

[Toxic#66]

Sure I have a graph mate

and RS Tuner Performance log if someone preffers

 

[Baal]

is that a before/after cam installation only?

is it vvt delete? how rough is the idle?

 

[Andyman]

is that a before/after cam installation only?

is it vvt delete? how rough is the idle?

Going by the spikes in the graph, at a guess erratic

 

[Toxic#66]

is that a before/after cam installation only?

is it vvt delete? how rough is the idle?

its after cams / vvt is still there / idle at 1250rpm

 

[Carbontec]

Baal I am not sure but if you have a group N car you can use only Ngroup cams or standard. Check in your homologation book, what is allowed. In group A at clio sport ITB probably are prohibited.

is that a before/after cam installation only?

Toxic I thought is it before/after (exhaust manifold from 4-1 to 4-2-1)

Toxic car is really fast from low rpm, I was shocked.

 

[Toxic#66]

Going by the spikes in the graph, at a guess erratic

As I said it's not fully mapped yet. I hope to see a bit higher top end power and a bit more tidy RR graph after I hook up my Innovate LC-1 with RS Tuner

 

[Martin_172]

who needs cat cams when you can get just under 190bhp and 160lb/ft on standard cams :clown:

 

[KungFuSpaghetti]

who needs cat cams when you can get just under 190bhp and 160lb/ft on standard cams :clown:

that could be 170bhp on another rolling road so it's a pointless comparison unfortunately.

 

[Martin_172]

that could be 170bhp on another rolling road so it's a pointless comparison unfortunately.

it was on the same RR all cars ran consistent power (ie 172 running 165ish and 182 running 175ish so just as pointless as the power claims stated above

 

[KungFuSpaghetti]

it was on the same RR all cars ran consistent power (ie 172 running 165ish and 182 running 175ish so just as pointless as the power claims stated above

lol, so true, I wont even bother on those

 

[Kam.]

Well i have a doubt, how can there be a "Group N" Cam if the FIA Group N does not allow any cam change?

Also i want a cam for my Rally Clio im not sure but the group N cams seem a little bit too mild, do the 428 work mid range or is too top end for rally?

Also, do both of these cams retain the VVT?

Group N regulations dictate that you have to use standard profile camshafts. The rules allow for manufacturing tolerances as the camshafts are mass produced. Quite simply catcams precision machine the group N camshafts to the maximum allowed by the rules. If you are running in group N and want to gain every last bhp available then this is a good idea.
For all other cars there are better profiles such as the 428s which will see bigger gains.

 

[Baal]

Group N regulations dictate that you have to use standard profile camshafts. The rules allow for manufacturing tolerances as the camshafts are mass produced. Quite simply catcams precision machine the group N camshafts to the maximum allowed by the rules. If you are running in group N and want to gain every last bhp available then this is a good idea.
For all other cars there are better profiles such as the 428s which will see bigger gains.

oh i see, thanks.