CUP ENGINE: MORE POWER?
#18
Race Car
I remember someone asking for a baseline above so here's mine from today.
Had literally 30 min on the dyno this afternoon with my stock 996 2001 Cup engine.
I say stock although I have added a 996 RS airbox and under-lid scoop ... but those shd have little impact on a stationary run.
I am running this Cargraphic Race exhaust tho w cats ... link
The dyno (Bosch) is a bit old but a good one as I understand it.
Unfortunately someone tripped over the RPM cable and ripped the wire out, breaking the plug so we didn't get RPM and hence Torque numbers.
But I was quite happy with the 01 (11 year old, raced for 8 of those, 15k kms, approx 150hrs) engines numbers and especially the shape of the curve.
I don't know much about Dyno's but this one adjusts for temp, atmos etc.. as one should. It was a scorching 30 deg today too.
Also being on the souther tip of Africa, it reads in KW (1 kilowatt = 1.34102209 hp).
So peak HP (adjusted) is 365. Quite happy about that considering that while alot of this car has been updated/renewed, the engine/gbox hasn't been touched.
Its likely that the curve would benefit from another 300-400 RPM - limiter at 7800 right now ...
but that might be what's keeping it in good shape.
I'll drop engine early Jan, leak and compression test, check coils and plugs etc..
but doesn't look like its time for a rebuild just yet. Counting on my aero and
Ram airscoop to make the difference. Ps this test was with normal (95) fuel - naughty I know but only can I had - usually run 102 octane.
Had literally 30 min on the dyno this afternoon with my stock 996 2001 Cup engine.
I say stock although I have added a 996 RS airbox and under-lid scoop ... but those shd have little impact on a stationary run.
I am running this Cargraphic Race exhaust tho w cats ... link
The dyno (Bosch) is a bit old but a good one as I understand it.
Unfortunately someone tripped over the RPM cable and ripped the wire out, breaking the plug so we didn't get RPM and hence Torque numbers.
But I was quite happy with the 01 (11 year old, raced for 8 of those, 15k kms, approx 150hrs) engines numbers and especially the shape of the curve.
I don't know much about Dyno's but this one adjusts for temp, atmos etc.. as one should. It was a scorching 30 deg today too.
Also being on the souther tip of Africa, it reads in KW (1 kilowatt = 1.34102209 hp).
So peak HP (adjusted) is 365. Quite happy about that considering that while alot of this car has been updated/renewed, the engine/gbox hasn't been touched.
Its likely that the curve would benefit from another 300-400 RPM - limiter at 7800 right now ...
but that might be what's keeping it in good shape.
I'll drop engine early Jan, leak and compression test, check coils and plugs etc..
but doesn't look like its time for a rebuild just yet. Counting on my aero and
Ram airscoop to make the difference. Ps this test was with normal (95) fuel - naughty I know but only can I had - usually run 102 octane.
Last edited by HiWind; 12-21-2012 at 02:01 PM.
#20
Race Car
understood .. that's why the leakdown etc.. but are you saying even if they're well within spec, not worth risking the bottom end?
The other MkI racing with me has 90k kms on it now ... solid racing for last 6 seasons and 35k kms. Untouched.
The other MkI racing with me has 90k kms on it now ... solid racing for last 6 seasons and 35k kms. Untouched.
#21
in my experience, thats a good bit down on power though ive no idea how much of a factor the fuel would be playing. if the other cup you run with was on a fresh engine then you would have a different take on things.
as mike has already said, you can run the engines for a really long time giving up power as you go, but you trash whats inside and end up with nothing left to reuse for the rebuild when you break it open.
as mike has already said, you can run the engines for a really long time giving up power as you go, but you trash whats inside and end up with nothing left to reuse for the rebuild when you break it open.
Last edited by outline; 12-21-2012 at 09:28 PM.
#23
Rennlist Member
#24
I wouldn't worry about it.
Watch for crankcase pressure spike
Compression/leakdown differentials that aren't fairly even.
Oil consumption change off baseline....
It's an 01 so all you can reuse are case intake and crank.
Rods, heads , valveltrain p's and c's will all have to be new when you update.
Use the heck out of it...
Just my .02
Watch for crankcase pressure spike
Compression/leakdown differentials that aren't fairly even.
Oil consumption change off baseline....
It's an 01 so all you can reuse are case intake and crank.
Rods, heads , valveltrain p's and c's will all have to be new when you update.
Use the heck out of it...
Just my .02
#28
Race Car
I wouldn't worry about it.
Watch for crankcase pressure spike
Compression/leakdown differentials that aren't fairly even.
Oil consumption change off baseline....
It's an 01 so all you can reuse are case intake and crank.
Rods, heads , valveltrain p's and c's will all have to be new when you update.
Use the heck out of it...
Just my .02
Watch for crankcase pressure spike
Compression/leakdown differentials that aren't fairly even.
Oil consumption change off baseline....
It's an 01 so all you can reuse are case intake and crank.
Rods, heads , valveltrain p's and c's will all have to be new when you update.
Use the heck out of it...
Just my .02
that was two years ago ... 43 hrs later and car still dynoing the same
and running well ... but now its time
#29
Track Day
Join Date: Mar 2013
Location: Milton Keynes, UK
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As an engineer I don't get all this Dyno talk that people say such a brand reads higher and this and that...If they're good products then they should be calibrated to some sort of standard.
7% is an ENORMOUS margin, it's like if you bought a micrometer and one said 1.000'' and the other one said 1.070'', .070in (around 1/16'') is a huge amount when you're doing machine work or any type of work for that matter.
It's good you tested all engines on the same dyno, at least if it's not accruate but repeatablity is good then you can compare results.
Good post, what do you use for engine development ? We use AVL-Boost for all of our engine simulations...
7% is an ENORMOUS margin, it's like if you bought a micrometer and one said 1.000'' and the other one said 1.070'', .070in (around 1/16'') is a huge amount when you're doing machine work or any type of work for that matter.
It's good you tested all engines on the same dyno, at least if it's not accruate but repeatablity is good then you can compare results.
Good post, what do you use for engine development ? We use AVL-Boost for all of our engine simulations...
#30