Well I don't know what is going on but here goes. When I first bought my car I went 120 mph like it was nothing, now when I get to about 80-90 it feels like it is struggling to go any faster. What could cause this? I read in the Chiltons manual and the only thing I got from that was a clogged catalytic converter..possible? And I swear a long, long time ago on this board someone else had the same problem and it was an O2 sensor that was bad. I also have the one range hotter NGK plugs in it, could that do it? I sure hope someone can help me. Thanks, Rob









-AF/X underdrive crank pulley
-AEM Cold Air intake w/bypass valve
-PIAA headlight and foglight bulbs
-Clear bumper lenses
-Eibach Pro-Kits with Tokico n/a shocks
-Pilot Motorsports Front upper, Rear upper, Rear lower strut bars
-PowerSlot rotors (all four)
-Axxis Metal Master pads
-RRE rear camber kit
-Dunlop SP SPORT 8000 tires
-ECLIPSE word on dash
-Red Mitsu symbol on steering wheel
-Painted fog light bezels
-Window tint
-Magnecore wires and NGK plugs
-Purple interior lights
-Purple hose kit

Maybe its the UDP? Physics say that a smaller diamater there would make it a lot faster in acceleration at slower speeds, but would take away top speed. Just a thought.


-Jeff
1999 Mitsubishi Eclipse GS-T'd

http://gs.dsmpower.com

LAST EDITED ON 25-Jun-01 AT 02:32 PM (PST)

I think you're think more about tire diameter physics than the UDP, the UDP frees HP and should have nothing to do with top speed since it doesn't interface with the gearing or transmission.

Steve "Phrenzy" - DJPhrenzy@aol.com
'99 Eclipse GS (sport) - Barcelona Red/Tan Leather
HRC Stage 2 @ 5psi
HKS W1 3" cat-back
Autometer boost/GReddy EGT
Konig Verdict 17x7 - Toyo FZ4 215/45ZR17
custom system, cosmetic mods...
On the way: A'pexi S-AFC

Old School 2GNTer
Now rockin an 05 SRT-4

...but suppose we have a big wheel and a small wheel on either end of a looped belt. (say a tractor wheel being the big wheel and a car wheel being the small one.) Now, if the driving force is turning the tractor wheel, which would represent the stock crank pulley, it would spin the car wheel very fast at top speed, but would take a longer time to reach that speed.

If you reverse it, and have the car wheel (UDP) powering the tractor wheel, it would get to top speed much faster, but the top speed would be very much reduced since there is less surface area (diameter of the wheel).

So in theory, while the UDP is lighter and smaller, making acceleration better, it would reduce the top end.

Am I anywhere close on this one?

I just came up with it on the fly. I also don't have a UDP yet, so I haven't actually seen it on the car.


-Jeff
1999 Mitsubishi Eclipse GS-T'd

http://gs.dsmpower.com

It was doing this before the UDP install.




-AF/X underdrive crank pulley
-AEM Cold Air intake w/bypass valve
-PIAA headlight and foglight bulbs
-Clear bumper lenses
-Eibach Pro-Kits with Tokico n/a shocks
-Pilot Motorsports Front upper, Rear upper, Rear lower strut bars
-PowerSlot rotors (all four)
-Axxis Metal Master pads
-RRE rear camber kit
-Dunlop SP SPORT 8000 tires
-ECLIPSE word on dash
-Red Mitsu symbol on steering wheel
-Painted fog light bezels
-Window tint
-Magnecore wires and NGK plugs
-Purple interior lights
-Purple hose kit

check the diagnostics on it to see if you're getting any codes for a bad sensor. does it run sluggish at all rpms?

or is your problem only at 80mph?

__________________________
...just my $.02
95 GS

____________________________
My $.02
95 GS