Just HOW much power do you get from taking off the cat?? Check it out
05-21-2008, 07:49 PM
#1
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Just HOW much power do you get from taking off the cat?? Check it out
My previous dyno was with my 300 cel cat that DOES pass california tail pipe emissions! i did:
301 whp on 91
343 whp on race 109 unleaded
NOW we took off the cat to really let the thing rip and put some much higher numbers down.
we did with NO cat:
310 whp on 91
352 whp on the 109
it does have some more midrange, and i do not have the new dyno loaded up yet, but 9 whp is all you get on a big turbo set up running catless. on a k04 it'd be less of a gain! i would recommend a nice 300 cel cat over the stockers though.
my point being, i think i'll be kind to the environment.
we also found there was more timing left in the car, meaning a good chunk more power but GIAC boys were already home when the car was on the dyno.......so that'll have to wait.
301 whp on 91
343 whp on race 109 unleaded
NOW we took off the cat to really let the thing rip and put some much higher numbers down.
we did with NO cat:
310 whp on 91
352 whp on the 109
it does have some more midrange, and i do not have the new dyno loaded up yet, but 9 whp is all you get on a big turbo set up running catless. on a k04 it'd be less of a gain! i would recommend a nice 300 cel cat over the stockers though.
my point being, i think i'll be kind to the environment.
we also found there was more timing left in the car, meaning a good chunk more power but GIAC boys were already home when the car was on the dyno.......so that'll have to wait.
05-21-2008, 10:27 PM
#3
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9whp sounds about right>>
I remember seeing that the STOCK cat bored out to 3" makes all of 10whp difference on a 600whp car. So say 5whp difference on your car with the cat and 4whp dyno/conditions inconsistency, and your results make a lot of sense.
05-22-2008, 03:49 AM
#4
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interesting thing is this>>>
i found the car smoother more so than faster! Boost transition now is comparable to a V6 normally aspirated car. Yeah....it is that good with my setup! ;-)
05-22-2008, 04:09 AM
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Losing cat to run 91 makes little sense. But losing it to run 109 makes a LOT of sense.
Put another way, running 109 leaded fuel will trash your cat, so no point in having it in.
