TechnoTorque or Underdrive Pulley

[dsisco]

Originally Posted by Johnny Danger

To clear the CEL, you would have to reprogram the ecu in order for it to disregard the fact that the cats have been deleted. In my experiencing, going "catless" resulted in a significant loss of low end and mid range torque. Since the 2.5 engine only has one set of cats, you would be better off upgrading to a set of high quality lower cell units. This, however, can be an expen$$$$ive .

my ecu already has powerchip software,
so u don't recommend removing the cats? losing torque is the last thing i wanted to do,

[Johnny Danger]

Originally Posted by dsisco

my ecu already has powerchip software,
so u don't recommend removing the cats? losing torque is the last thing i wanted to do,

I am not a scientist, nor do I play one on TV . Again, however, it was my experience that going "catless" resulted in a significant loss of low end to mid range torque by virtue of the fact that there was hardly any back pressure left in the system. The astute exhaust designer knows that you must balance flow capacity with velocity . In some cases, reducing velocity by means of an exhaust system that is too free flowing can greatly impact low end to mid range torque . This is better explained through the concept of how delta pressure works. I am sure that there is someone on the forum far more versed in this topic than me.

[JTP]

Originally Posted by ronoroa.zoro8

Techno pair is a piece of Peter, which replaces the T after the throttle body intake plenum. The interior has been modified to reduce the turbulence created when the incoming air reaches the pipe T. The 2.5L engine has a unique set of cats, it is better to get a set of high quality units lower than the cell.

WTF? This is some weird combo of other people's replies and BS.

[Johnny Danger]

Originally Posted by JTP

WTF? This is some weird combo of other people's replies and BS.

This person also replied to my thread, "986 Turbo" ? I have no idea who they are, or what they were referring to ???

[dsisco]

got my car back, installed new water pump, engine mount and LN thermostat,
my car feels like a different car!

highly reccomend the low temp thermo, car runs alot cooler, so i think the ecu runs more aggressive ignition timing.

problem i had was with the underdrive pulley, my mech says its totally wrong for my car, even with shaving down the boss

gonna take it to another guy for a 2nd opinion.

need to know if anyone has fitted the new style BBI pulley see picture

[harryrcb]

[QUOTE=need to know if anyone has fitted the new style BBI pulley see picture[/QUOTE]

Yes I installed one, works great.. don't know what your guy reffered to other than the fact it's harder to hold when you tighten the bolt and does not have any TDC marks on it. Just keep your old pulley in case you ever need to do cam timing or install the LN eng IMS.

[IMG]smaller.jpg[/IMG]

[Johnny Danger]

Originally Posted by dsisco

got my car back, installed new water pump, engine mount and LN thermostat,
my car feels like a different car!

highly reccomend the low temp thermo, car runs alot cooler, so i think the ecu runs more aggressive ignition timing.

problem i had was with the underdrive pulley, my mech says its totally wrong for my car, even with shaving down the boss

gonna take it to another guy for a 2nd opinion.

need to know if anyone has fitted the new style BBI pulley see picture

I am using the BBI pulley on my vehicle with no issues whatsoever. Tell your mechanic that he is far afield on this one .
JD
p.s. Its important to know, that a shorter belt is required to accommodate the smaller pulley.

[BudmanV24]

Has anyone noticed higher operating temperatures due to under-driving the water pump too? Or does the decreased load from spinning the other components at a slower speed make up for that? I don't think I've seen anyone discuss this.

[Keith Newby]

I think previous posts stated that there was no increase in engine temp. attributed to the under drive pulley. Of greater interest to me was the mention of a power steering under drive pulley on the market. I may be wrong but I would think the power steering pump takes more power to run than the water pump...and as a person who would never grind away an engine boss, the more elegant steering bolt -on strikes a chord.

[Topless]

Originally Posted by BudmanV24

Has anyone noticed higher operating temperatures due to under-driving the water pump too? Or does the decreased load from spinning the other components at a slower speed make up for that? I don't think I've seen anyone discuss this.

Tests by Flat6 indicate that engine temps run lower with the UD pulley. I don't know if it is due to impeller cavitation at higher RPM with stock pulley, or just a better heat transfer flow match.