Turbo upgrade with stock parts?

[Billman]

my 1994 RS2 Model year 95 has these but dont know if it is really true.

[GazzaG60]

there is a lot of theoretical maxes. there has to be otherwise thers only broken parts.

no i haven't broken a rod. i dont want to. prevention is far better than a cure.

i think that most rods are ok. the issues come on poor fuel or maybe a driver error. a stronger rod will help here. may give you that margin for error.

why find the limit and empty the bank for a new engine?

[rs200]

Also why do people say that 3b and aby/adu use different rods? Atleast acording to etka they are the same and i cant seem to any evidence that they where upgraded.

there is a little different betwen 3b and adu rods... little visual different, but sizes and strong of them are the same...

[Jamo]

Mihnea said the casting of the 3B rods are stronger , can't find the post though

This is interesting though http://www.s2forum.com/forum/showpos...86&postcount=5

[Jonas_R]

there is a lot of theoretical maxes. there has to be otherwise thers only broken parts.

no i haven't broken a rod. i dont want to. prevention is far better than a cure.

i think that most rods are ok. the issues come on poor fuel or maybe a driver error. a stronger rod will help here. may give you that margin for error.

why find the limit and empty the bank for a new engine?

I agree with you that there has to be a limit otherwise the rods will fail at some point.

However if there is a underlying course of the rod failure, ie preignition due to the ignition system (distributor 3B). Then a stronger rod wont help on that problem.

I guess it comes down to time and money, opening up the engine and changeing the rods is a bigger job then changing the turbo etc.

[Rocco]

stock 220hp are too much for oem rods in 3B engines?

i bet 1000€ that there was some other problem around for broke the rods

[MrVain]

I drove my S4 1992 model with a IRX450 turbo (same as K26/27 with size 10 hotside) with 1.8 bars of bost for almost three years. No problems and no bent rods Reved it up to close 8000rpm sometimes....

[Billman]

One could say there that this turbo spool late so the high boost is upper the rev range. Read a thread from pisobiker about rod stress and you will understand what I am talking about.

[MrVain]

One could say there that this turbo spool late so the high boost is upper the rev range. Read a thread from pisobiker about rod stress and you will understand what I am talking about.

wasn´t that late.. full bost at 3800rpm

[GazzaG60]

i understand billman.

lower RPM torque is more damaging than high RPM. how try this is im not sure. i think its more the fact that at low RPM is a big surge and your just getting parts moving. its the sudden shock that breaks things.

subarus have that issue with gearboxs. its the small turbo torque spike that hurts. bigger units that deliver more slowly dont hav this issue.

im not for chancing it myself.

i think 3b rods use the same casting as 16v ones.

its up to the individual i feel really. i wouldn't be unhappy posting about a bent rod in future though if your in the "itll be fine group"

[Rocco]

so in theory it is easier to bend rods with the RS2 turbo than k26/27 or a little bigger turbo true? because it has around 500/700rpm or delay in spool up ?'

[ADU-power]

Im a bit confused now, a lot of disagree about the rods i see.
I dont have the knowledge and the money and time to get the engine out and put al new parts in and balance it out and put it back im affraid.

I thought to install the Garret GT3071R-0.63 on my car that it will be safe on 400-420 Hp and 550Nm on a remap.....

[hoffer76]

stick with rs2 turbo and run a slightly more aggressive map, no point spending at least a £1200 downgrading to a 3071

[hoffer76]

rocco the k26/27 you have could bend your rods just as easy as rs2 unit if mapped poorly

[EspenW]

Mihnea said the casting of the 3B rods are stronger , can't find the post though

This is interesting though http://www.s2forum.com/forum/showpos...86&postcount=5

Good find: Interesting that the Heinz Lehmann built Audi Sport engines ran 700hp on the stock rods, that likely means he didn't take max rpms that much past the stock rev limiter, as the design criteria for OEM rods is infinite fatigue life at max allowed rpm. Going to an expected 8000-8500rpm would likely have fatigued the rods fairly quickly, as that is well past their expected design limit. I've seen Joe Hoppen Motorsport in the US mention this before. Back in the day, they kept bending rods on their race engines, they called Audi and asked for stronger rods, Audi said that was not necessary, but advised to beef up the ignition system. JHM did so and stopped bending rods.
The boost pressure that Mihnea mentioned seems odd, though, as these Audi Sport Engines developed by Lehmann are quoted to have run about 2.3 bar and close to 800nm.