Colombo & Bariani Cams vs Catcams?

[btaser2]

I have colombo bariani 286-278 degree cams installed. i also have forged pistons with 13.1.1 compression, forged rods and upgraded valvesprings and retainers. I am thinking of upgrading these cams to a morenaggressive one with hogher lift durations but without having to change from hydrolic to mechanic.

I saw catcams camshafts. What do you recommend?

 

[chiefkadir]

Up up

 

[Aydon182]

I wouldn't spend money changing the cams C&B's are good anyway, even if you get more aggressive cams your Gunna see very small gains, spend the money on ITB's or experiment the RS2 with cams method

 

[Dan519]

Those cams will be limiting the engine with high compression IMO

 

[maupineda]

Your C&B cams are actually more agressive than 438 and even 421 duration and lift wise

 

[Dan519]

Your C&B cams are actually more agressive than 438 and even 421 duration and lift wise

not even close. I'll dig out the figures

the total duration is longer on the C&B's, but the ramp rate is very gentle so the lift at TDC is far milder

for high comp with uprated springs you should be looking at 422's anyway

 

[Chip-mk1]

You are a bit limited for moving on very far with the cams if you dont want to go mechanical TBH mate.

423 catcams would be worth a look as presumably you have big valve cutouts etc? Thats about the hottest cam I can think of that doesnt require you to go mechanical.


I assume you are on bodies?

 

[Chip-mk1]

not even close. I'll dig out the figures

the total duration is longer on the C&B's, but the ramp rate is very gentle so the lift at TDC is far milder

for high comp with uprated springs you should be looking at 422's anyway

The figures are on their website mate:
http://www.catcams.co.uk/acatalog/Renault_clio_rs.html

 

[btaser2]

Yes we will install the ITBs very soon. We are actually considering to go with the 423 series which are far more aggressive than the colombo barianis even without having to change to mechanical followers. We already have 13:1:1 compression wössner pistons and forged rods plus a headgasket for more compression so I think we have almost all the setup to feed those catcam cams. What do you think?

 

[Dan519]

Yes we will install the ITBs very soon. We are actually considering to go with the 423 series which are far more aggressive than the colombo barianis even without having to change to mechanical followers. We already have 13:1:1 compression wössner pistons and forged rods plus a headgasket for more compression so I think we have almost all the setup to feed those catcam cams. What do you think?

thats exceptionally high compression. I think you'll be quite heavily limited by detonation. Are you planning to run race fuel of a higher octane?
422s/423's sound like the right choice to go with the rest of the parts, I just question the merit of going past 12.5:1 (which is very high, and also going to limit you)

 

[steviet]

Do some countries not have Ethanol in their fuel???

 

[btaser2]

Yes we will use race fuel. We already tested the race fuel with the existing setup and the difference was quite promising. Anyway our 97 octane gas quality is very bad. Our 97 octane correponds to your 93 octane most probably. May be even less than that. Cause the 97 octane that's sold in Turkey is not pure 97. Its Very bad quality 95 octane + mixture. So we are not sure what they add to try to get 97 octane

 

[Chip-mk1]

Uk fuel isn't brilliant either tbh, certainly not like in Japan or the states.
With cr that high you certainly want the best fuel you can get or you'll end up with not enough timing which will push peak cylinder pressures too late in the cycle so I'm not surprised it responds well to race fuel.

 

[Dan519]

Yes we will use race fuel. We already tested the race fuel with the existing setup and the difference was quite promising. Anyway our 97 octane gas quality is very bad. Our 97 octane correponds to your 93 octane most probably. May be even less than that. Cause the 97 octane that's sold in Turkey is not pure 97. Its Very bad quality 95 octane + mixture. So we are not sure what they add to try to get 97 octane

it's crude, but you can improve octane with celulose thinners if you struggle for good quality fuel. Thinners are made up of Toluene, Xylene and ethanol. The biggest gamble you have with this, is the concentrations of each are unknown and can vary from can to can. I've used it in the past though and it's certainly effective

 

[Chip-mk1]

I've still got some neat toluene knockin about, that's excellent for upping octane rating, smells mega too, lol.
Not sure how easy it would be to get hold of in turkey though, it's much harder in the uk now due to all the anti terrorism stuff.