New P5 owner...plans and a couple questions!

SoCalMP5

Member
:
02 P5
Hey there,

Not new to modding cars - but new to this one! Inherited a P5 due to a death in the family. I am not a huge fan of Japanese cars, but this thing grew on me right away, and it's my new daily driver. I also own a (325whp) Volvo, which has now taken "weekend" status as it's now on E85 exclusively! The P5 is blue, with about 81k miles on it. Body is a little beat up, but that's OK, it was a desert car. Engine runs great; I just had it smogged, and many of the results were "0.0" or "0.01" units measured at the tailpipe. This thing runs CLEAN!

Things I love about the P5 so far...
1) Nimble! It's not as light as the size leads one to believe (at over 2,800 lbs), however, it handles as if it weighs at least 150 lbs less. Solid chassis. I'm tempted to test it out!
2) Economy! Going from a turbo automatic on E85, to an N/A 2.0 manual on gas, I can't help but love it. 5th gear is a little buzzy, but I'll fix that in time.
3) Styling. This is a good looking car, and the size is perfect. Small and nimble, but enough room for me and my passengers or gear (I'm 6'1" and 225 and I don't feel particularly cramped).

Issues...
1) Please see bottom of this post for my "VTEC" problem! (boom06)
2) EVAP leak CEL (P0455). Tried the "tap and clear" on the purge valve in the intake pipe, no luck. Gas cap is OK. I just keep resetting it. My smog guy passed it for me anyway so it's more an annoyance than anything else. I'm not sure where to look next.
3) Clutch will sometimes chatter, and the action is at the very bottom of the pedal stroke. Also have to have the clutch pedal on the floor to start the car. I'm assuming it will need a clutch soon. Can't be that expensive so I'm not too worried about this.

Plans for the car...
Since this is the daily and gas is stupid expensive, and because this has an anemic ULEV 2,0L in it, and because I already have a turbo car...I'm modding in the direction of eco/hypermiling. Nothing extreme, but that will be my main focus. Fortunately, many of these mods will also improve performance. I'd like to improve on the handling as well since that's its strong suit. My city driving is getting 24-26mpg, and the last all-highway tank was ~30 mpg. This past tank was all city; the low fuel light came on at 328 miles. Filled up at 350 miles, and it took 13.2 gals. (My Volvo goes only 275 miles on 16 gallons of E85 with mostly freeway driving!). I know I can do better; that is before any mods. Some of my thoughts have been...
1) When the clutch gets replaced, lightened flywheel goes in
2) Perhaps lightened pulleys
3) Springs + undercarriage sheeting (less air under the car, less turbulence on components)...maybe swaybars for fun?...Rota wheels or similar (weight reduction...Slipstreams are only 13.X lbs in 15")
4) Thin plexi over the grill and fog lamp openings (reducing air into the engine bay, reducing drag for hwy mpg)
5) Thought about an MP3 ECU for when i wanted more spirited driving, just to swap in from time to time...but there's probably an easier (cheaper) way to trick the ECU into bumping the ignition timing. Gonna do more research here.
6) 626 5th...it's just too short.
An air filter is a given; I won't do an exhaust as I want this car to stay quiet. My other car is mostly gutted with a wide open exhaust. Really can't wait to see what I can get out of it. I think I can get 34 mpg highway (that would be a gain of almost 60 more miles per tank) without doing anything extreme like a fugly boat tail or something. lol. Plus, with the suspension mods, it will be more fun to drive on curvy roads, and the lighter reciprocating mass would mean better acceleration if I did have a reason to mash the throttle. :) If I really want to go faster, though, I get in the Volvo. haha.

One issue I'd like to know if other people had:

The car feels like it has "VTEC", especially noticeable when it's cold. In other words, as I go through the gears, the car behave one way up til about 2500...but then, somewhere around 2500-3000, it will all of a sudden "open up" and the acceleration is much stronger. Feels almost like a VVT crossover or a variable intake manifold not working right, but I have no idea. It doesn't *seem* to do this when fully warmed up, though I could be wrong. Is this a common issue, or is there somewhere I should look first? Links would be helpful as Mazdas are totally new to me.

Anyway...thanks for the info I've read so far! My Volvo is a little jealous now that the Mazda has been getting my attention!

Gratuitous vid of my Volvo and a buddy with a modded Mazdaspeed3!
http://www.youtube.com/watch?v=pbS5jAbBWRw
 
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welcome to the pro5 family!
the 5th speed swap caught my attention..
whats the ratio diff. between those two? (and I agree p5 5th speed is.. ehh.)
 
Thanks! I'd have to look up the exact ratio again, but it's somewhere around a 10% reduction. I don't want to swap the whole trans, as then I have a feeling 1-4 will be too tall for the 2.0L. I just want 5th to rev a little lower so it's more like an overdrive.
 
I've seen a lot of talk about the 626 swap, but never any direct feedback on the end result. Has anyone successfully done it? And what is it like?
 
that vtec feeling you are talking about is more than likely the butterflies in the intake manifold opening up.
 
that vtec feeling you are talking about is more than likely the butterflies in the intake manifold opening up.

Do these ever have problems? I guess what I'm wondering is...is it normal to feel them open more when cold, rather than once it's fully warmed up? Thanks for the info so far! Does anyone mod these to keep them permanently open?
 
^ NO worries.

Will not 'buy its way onboard for fuel economy mods $/MPG Improved':
Lightweight clutch
Wheels
MP3 ECU

What will:
Header
High flow Cat
Underdrive pully
Low restriction K&N filter
Taller tires (better final drive ratio)
 
Well, the ecu as I mentioned would be "hot swapped" when I wanted to play in the canyons. That wasn't for mileage. ;)

Though, I'd be willing to bet the light flywheel (which usually equates to 7-15 lbs of reciprocating mass removed depending on the car) would have at least as much of an impact on economy as the crank pulley (minus 1-3 lbs and the slight reduction on accessories).

And losing 5-10 lbs per wheel of unsprung weight is HUGE...far more than a crank pulley could ever hope to do. Taller tires would probably net a loss in economy by adding weight and requiring more force to accelerate the now larger tire diameter for every time you're not just cruisng at highway speeds (light to light losses). It's like hopping on a 10-speed with the chain on the largest front sprocket...requires more effort to get going, but less rpm to keep rolling once at speed. If I did 300 miles of highway driving per tank, then for sure, a taller tire would help.

Plus...the car would have the fringe benefits of quicker accel and better handling...when I wanted it of course. :) I don't have any delusions of it ever being fast, though...I've seen the dynos. Lol!

Thanks for the 411 on the intake butterflies!
 
i also feel that 'vtec' feeling... i just use it as a marker for when to shift for better mpgs
 
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