Hi Stephen You may like to actually try driving a DeLorean that has been de catted - and by this I do not mean simply gutting the contents of the existing cat*. The exhaust note changes noticably and the engine is without question perkier. I have no dyno sheets to prove this, but if you can find one owner who has a cat bypass pipe installed and did not experience greater performance, I'll eat a cat for tomorrow's breakfast :-) Meoww Remember the DeLorean engine is unusual for a PRV in that it is catted - for 1981 this was very rare. ALL the european versions run considerably more horsepower and this all comes down to the fuel system not requiring a lambda system to keep a perfect mixture. Running rich can be good for performance if tuned properly. Our euro converted engines are considerably more powerful, still running a stock exhaust, cat bypass and european B28E ignition and injection systems. One customer discovered his clutch was worn out immediately after collecting his car after the upgrade. * I have one customer to whose car I fitted a cat bypass pipe. His old cat had a perfect hole strait down the middle. Despite this, he still reported improved pickup and crucially a marked increase in fuel economy. By suggesting the DeLorean's stock exhaust is "tuned" is rather amusing really :-) FYI catalytic converters were not mandatory in the UK till 1994 so we can legally remove them over here, and sell the pipe to do so. Are we being environmentally unfriendly? I suppose so, but we are burning less fuel doing it, so you could argue we're actually cutting down on CO2 emissions! Martin Stephen Schlachter wrote: >See my previous posts about removing the cat. Doing so increases >emissions, and adds no performance (and may even hinder it). Just >because you can't see the extra pollution doesn't mean it isn't there, >and backpressure is part of the overall exhaust tuning. > >The only reason to remove the cat is due to malfunction...and then, >only to replace it. If someone has a dyno test that demonstrates a >measureable improvement in performance by increasing pollutants, I'd >like to see it. > > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/