which cams!!!!!!!!!!!!!!!!!!!!!

[S2central.net]

Actually - Jamo makes a good point (for once - ohhh couldnt resist)...

garrett turbos have a reputation for surging if mapped too aggressively - but the less aggressive lift of ABY/AAN/3B EX camshaft would reduce that tendency to surge...

Running both 7A cams seems all wrong with all that overlap nonsense... will need timing wheels to dial that out IMHO - is that what Audi_CQ did ?

[trackslag]

these are waisted look at top pic hard to see but im sure they are

http://www.034motorsport.com/product_info.php?cPath=28_63_73&products_id=396

[S2central.net]

Yeah - but are they sodium filled ?

[trackslag]

Yeah - but are they sodium filled ?

they are Inconel which i was told are very good dont know much about sodium filled,whats idea with that is it to stop valve burning/keep heat down?

[lind4hl]

they are Inconel which i was told are very good dont know much about sodium filled,whats idea with that is it to stop valve burning/keep heat down?

yes.

[trackslag]

would they be needed on a 400bhp track car? seems abit over kill if most people are running on stock.

[lind4hl]

The 034 valves? no
the OEM valves must be sodium filled, right?

for 400 bhp you dont need anything done with the head really..

[S2central.net]

Yip - the sodium liquidises inside the valve stem and improves the thermal efficiency of the valve by transferring heat into the guide and mass of the head.

[trackslag]

Yip - the sodium liquidises inside the valve stem and improves the thermal efficiency of the valve by transferring heat into the guide and mass of the head.

YIP??? whats that mean?

[lind4hl]

YIP??? whats that mean?

in plain english, not the Professor Paul language

they cool down the exhaust valve

[S2central.net]

@trackslag - save your money - no need for all these 'uprated' parts just cos they are there... Plenty here proven 450bhp and beyond by simply bolting on 3071 to RS2 or better manifold, added bigger fuel injectors and a custom remap... Flowed heads and such are nice to have but not essential at all.

[Audi_CQ]

right guys need best info here on cams, the cams in question are 7a/rs2/s2(stock)
with the 7a/rs2 cams is it the extra lift that gives better power or the fact the they change the timing BTDC and increases the power. On paper a turbo engine would work better with higher lift of the inlet side not on exhaust side eg more air/fuel faster there for faster and greater bang!!!. i need to know abit more about over lap and changes in timing, i think this maybe where some of this extra power people getting with the exhaust cam changing. there must be some techies on here with the info............

Copied from another thread:

If your engine is stock or just chipped, don't use 7A cams. If further mods are planned try this:
If using std parts set cams on std marks.
If using 7A cams with adjustable cam pulley, try to set them 5 degrees adv.
If fully adjustable "chainwheels" is used set ex 5 deg adv , and inlet at std timing.


In this case of 7A cams you get a lot of different answers. Why? Different engine setups give different results. You always has to find the weakest link in your setup. If cams isn't the weakest link you get little or nothing out of changing cams.

In a stock/near stock(chipped) engine the weakest link on the exhaust side is the restrictive EM and turbo. Since they create a lot of backpressure you have to use cams with little or no overlap to avoid exhaust blowing into intake at overlap. 7A ex. cam has the same cam timing as std cam, just more lift, so doesn't harm. Very little gain so if not planning for further mods I wouldn't change it.

On inlet side the problem is again the turbo. It just doesn't have a lot of capasity, and when the turbo can't deliver anymore it doesn't help what intake cam you use. Turbo is maxed out anyway. Limit is about 270-290 real hp on a chipped but otherwise stock engine. The turbo will be empty long before you get to the kind of RPM where the 7A inlet will help out (~5k) so no use for the extra duration here so stay with the std inlet.

Just my 0.02$

Cheers,
Roger

[S2central.net]

Nice info Roger... Can see how the chainwheels can be used to good effect there and dial out the overlap with 7A cams.

I suppose its the longer duration of the 7A-IN camshaft that pushes its peak further up the revs. Interestingly the NM inlet is about halfway between ABY and 7A inlet wrt duration so it would be an intersting one to try - assuming the lift is the same.

[GazzaG60]

when i was doing the 16v which is basically the same head i was gonig for a full head job. that would have been serious porting on both sides but maybe 2x the work on the exhaust. this is most important area. i was going bigger valves with full port matches etc.

for your target you dont need anything doing. pick the right turbo and manifold setup, good cooling and tuning and ill go. one area maybe worth a look at would be a fully balanced and maybe slightly lightened bottom end to improve resonse.

i run the 7a ex cam and it induces a more laggy-draggy feel. over 6k its better. maybe worth it on the track but not on the road. could be solved by a pair of 7a and soem timing wheels maybe to dial a bit of overlap out. not sure what it is but im told it needs to be set to 10-12 degrees. thats what i was told for my solid lifter 16v schricks to get um on FI proper.

[trackslag]

hi what about 7A inlet cam (224deg 10.5mm lift) timed at 110deg and use the 205 deg 8.5mm exhaust cam from ADU, timed at 120 deg seem like a good use of stockcams?
Dose anyone have these above cams laying around that would be for sale??