yeah he is right. i find myself a conservitive on most of the political stuff but im pretty sure global warming is fact. and besides. i didn't have cats on my custom magnaflow setup but 1. it sounds too raspy with only the muffler. 2. it smells like shit. and 3. it IS bad for the enviroment.
i just threw a high flow cat on from magnaflow on. it was like 60 bucks so its not very expensive.
94' 325is *sold* | 95' 540i/6 | 02' CBR954RR
1998 E36 Euro M3/4/6 Aegean Blue/Ox Blood
2003 E46 M3 AW/Bl - sold
1997 E36 328i AW/DG - RIP
hey kabal what is that on the back of your bumper?
94' 325is *sold* | 95' 540i/6 | 02' CBR954RR
i thought it was a tow hook but if it was wouldn't it be lower under the bumper cover?
94' 325is *sold* | 95' 540i/6 | 02' CBR954RR
damn, I should really change my sig pic, maybe a front view, people always ask
got it like that, and yeah, seems they did a crap job, cause the "diffuser" is cut in the middle.
was going to remove it, then got my dirtbike, and needed to tow my trailer.
FatJohn325:
1998 E36 Euro M3/4/6 Aegean Blue/Ox Blood
2003 E46 M3 AW/Bl - sold
1997 E36 328i AW/DG - RIP
yeah when i first saw it i thought it was a penis. then i thought better of it.
94' 325is *sold* | 95' 540i/6 | 02' CBR954RR
Early M52 E36's might have had only one pre-cat oxygen sensor in the exhaust, just before the CAT, and one post-cat oxygen sensor, after the CAT.
Most of them (and in the US probably virtually all of them) have two pre-cat sensors (in the exhaust manifold, one for each bank), and two post-cat sensors (after the CAT, again, one for each bank/pipe).
So to prevent CEL I think you'd night two anti foulers for both post-cat oxygen sensors.. Or, if you have only one post-cat sensor, then you'd need only one.
It's an old thread, but here's some interesting info. A lot of people think a catalytic converter reduces torque and HP quite a bit. True, it reduces it a little, but what really caused the major drop in torque during the eighties in many BMW's is not the fact that it had a catalytic converter, but the fact that BMW had to lower compression in the cylinders quite a bit because catalytic converters die quickly when you use leaded fuel. And the lead was used to lower the risk of self-detonation. As there were no lead-free high-octane fuels available like nowadays, BMW had no choice than to lower compression substantially.
So, for example a model 1 E30 325i (1986) in Europe didn't have a catalytic converter and used a high compression CR=10.0 CR if I'm correct (might have been 9.7 perhaps).
Then came model 2 E30 325i (1988) in Europe and it came with catalytic converter and BMW had to lower the compression to CR=8.8 if I'm correct.
That compression drop caused a major drop in torque down-below, and combined with the increased weight, the model 2 325i felt a lot slower, and was slower.
Same for the very early 1986 E32 735i. It came without CAT and the M30B35 delivered 220HP (CR=10.0). Then, the later models did have a CAT and HP dropped to 211HP (CR=9.0) and the torque curve worsened quite a bit. It was primarily caused by the lowered compression, and not by just including the catalytic converter in the exhaust..
With the earlier M30B34 it was even worse.. HP dropped from 210HP (CR=10.0) to 188HP (CR=8.0) in the CAT version.
When the M50 came to the market, fuel quality had already improved, and knock sensors were used, and better engine design also prevented problems with pre-detonation. So compression ratio's were up again. CR=10.0 - 11.0 in common M50/M52 models. Within same generation (i.e. M50 vs M52), the lower the displacement, the higher the CR;
M52B20 = CR11, M50B20=CR10.5, M52B25 = CR10.5, M52B28 = CR10.2, M50B25=CR10.0, even while a CAT was installed.
So, don't expect miracles by just removing the CAT. It will help a little, but nothing as spectacular as a substantial increase in CR.
Last edited by ed323i; 08-15-2018 at 12:30 PM.
1997 E36 BMW 323i (European) 275k km (171k miles), with following small mods:
- Chip tuned DME (190HP/257Nm); 328i dual pipe exhaust (plug&play); Meyle HD control arms, Bilstein B4 shocks
- Fan delete mod: Stock 92C thermostat, 80/88C temp. switch, 80/20% water/coolant; INPA says temps 100% OK
- Throttle body coolant hose delete mod; Comprehensive ASC Delete option list; Solved: -30 additive adaptation values
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