rs2 camshafts on s2 aby

[valjo]

hi!

is it necessary to change timing bell, water pump and camshaft drive wheel for upgrading s2 aby with rs2 camshafts.
those parts arent the same on aby and adu engine according to parts catalogue.

thanks

[Rusty]

Cam pulley is 10 degrees retarded over S2, you should fit this if you get RS2 cams if you want to get the most out of them. Cams have been discussed before, ABY inlet with 7A exhaust is best FWIR.

Water pump has a smaller pulley but it's not necessary to change this as long as you use the ABY S2 belt. Samller pulley means that the pump spins faster and thus moves more water, this is a good upgrade for more tuned engines as the parts cost about the same S2 to RS2.

Don't know what you mean by timing bell, if you mean timing belt then it's different because of the RS2 water pump pulley being different, only required with an RS2 WP (as mentioned above).

I am running RS2 WP and belt on ABY cam wheel and it all fits a treat.

HTH

[valjo]

so andy if i understand right, i should use rs2 Cam pulley but other parts could be from ABY, and it will works at it should?

[Rusty]

Yes. If you need to replace the water pump then get RS2 pump as it's better and RS2 cambelt to suit, otherwise leave it all and get the cams in there. RS2 cams give good torque but ABY/7A are better for power, do a search for them.

[GazzaG60]

the 7a is better for lag.

i think the 7a needs an adjustable timing wheel to get it correct.

[valjo]

i am only looking for rs2 upgrade 7a is not an option.
so cam pullery and that is it

[Knight Rider S4]

the 7a is better for lag.

i think the 7a needs an adjustable timing wheel to get it correct.

To what degree do you think would benifit? 5 degrees?

[GazzaG60]

id say so. im gonna put the standard one back in i think and try. i expect a large increase in bottom to middle pull. i expect a peak also around the 5-6k mark. maybe flattening a bit after that.

with the 7a in i get a more steady pull shall we say. it doesn't feel as strong at any given boost level until around the 5800 mark then i feel it pull harder for the rest of the rev range.

i exect i will get a pair of cam wheels and set them using a lift gauge and degreeing wheel. around 5 degrees is what i heard. 10-12 degree overlap is what i will aim for. i saw a graph somewhere with the different timing versus HP. 5 degress was their best find i think.

i would try RS2 but i dont have a set. also the best cams for the 16vt used to be standard valve ones or 2 exhaust cams. you cant do the 2 exhast cams on the audi the same as i dont know anybody who makes the toothed pully with the keyway cut 7 degrees off. that was the 16v difference anyway. on the 16v this gave better throughout the range. this was the developed route for the original 16vt.

has this been done on I5 by anybody?

[Rusty]

You could do 2 exhaust cams on an I5 without the dizzy. I was looking at the RS2 exhaust cam as it's similar to an ABY inlet with more lift and a touch more duration. Wouldn't be cheap tho.

[GazzaG60]

id prefer 2 exhaust cams. i run aby so no dizzy. i bought 2 7a cam sets to do it but was stopped by the toothed pulley. i had a 16v one at the ready but its not right.

thats the way to get lift. i had 11.2mm on both cams for the 16vt. increases flow somewhat too.

its hard to drive a fairly flat big turbo motor on the streets. a well tuned standard motor would give it a run unless i can see the top of third. then it goes from being a very close one to not close at all.

[Rusty]

Yeah, my car is easy to drive, as long as you're over 2500 there's plenty there.

[GazzaG60]

i see 0.5bar at 3krpm, around 1 bar at 4k and from there is a rapid rise to full boost.

hard to get on boost, hard to drive on boost. id expect great on the track though.

im gonna look at boost control and keeping the gate shut longer. hopefully ramp in faster. think i got some gate creep going on.
2nd and third are like a rowing ore

sorry to be off topic

[Rusty]

Better to work with the characteristics of the turbo you have than fight it I guess. RS2 is still quite a reasonable sized turbo and seems to do most things well on the RS2 cam setup so all should be well with all RS2 parts.

[GazzaG60]

the turbo is great. my cam choice isn't

on standard cams the car wasn't as much a pig to drive. i am still only running at 1.35bar and the fuel is over so i need to put the pump in sooner rather than later.

rs2 turbo is too small for me. i want, need 500hp. had 320+ since 2 monhts after buying the car.

[Jamo]

7A was a fad cam. If you've got a garrett stick to stock unless you can get some schrik cams.

RS2 exhaust is a good cam, you gain up high but don't loss low down like the 7A