Martin, As you well know, there are other differences in the USA/EUR DeLoreans than just the cat. I'm not versed in these differences, but I know that it's seldom a simple matter to alter a single variable within a complex system. Removing the cat on US vehicles may or may not increase performance, and I would like to see a dyno test that shows the difference. Removing the cat will almost certainly increase emissions. If I could get another 10 or 20 HP by cutting out the cat, I'd be under there with a hacksaw right now. But in truth I think it's 1 or 2 HP, which hardly seems worth the effort (let alone the extra emissions). Don't worry about the higher emissions in your Euro-spec cars...you'd need to leave every vehicle in Europe idling 24/7 before you'd even come close to catching up with the USA. We're #1, woo hoo! Gus Schlachter VIN #4695 Austin, Texas dmcnews@xxxxxxxxxxxxxxx wrote on 09/23/2005 07:39:12 PM: > 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 > > > > > > [Non-text portions of this message have been removed] 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/