Project: Mazda Protege5

[SoCalMP5]

Hey gang,

I doubt anything too extreme will happen here, but I thought I'd keep people posted anyway. My story with the P5, in a nutshell, is that I inherited the car from a family member who passed away. It is in "fair" shape cosmetically, but seems pretty healthy mechanically. And since the engine in this car has NO balls what so ever, I've decided to make this the daily driver, so I can retire the Volvo to weekend/drag strip status as it runs on E85 (currently at about 390hp!).

In all-stock configuration, and split city/highway driving, I was seeing between 26 and 28 mpg per tank, average.

I then installed a cone filter, and my commute changed to favor mostly highway driving - after a couple tanks, I've reached 31.96 mpg (416.5 miles on ODO, with a fill up of 13.03 gals. on the last tank).

Not too shabby, considering the government/manufacturer claims of 22 city/28 highway/24 combined.

And the combined average of 26 mpg (compared to my 29.5) across the 106 Protege5's (2002 model year) tracked on Fuelly!

Today, I installed some plexi on the front end to smooth airflow and reduce the amount of air passing through the engine bay. I left the small upper grill open so the poor radiator can breathe a little, and propped the rear of the hood up (not in the pic), and removed the rear hood seal at the rain tray to allow hot air to escape more easily.



Some specs on the Mazda:
- About 2,750 lbs curb weight
- 2.0 PZEV
- 130hp, 135tq
- 5 speed manual
- 205/45/16

The car is full weight, with crossbars and the sunroof baffle still installed. I'll report back with the results of the next couple of tanks, and the plans for future mods. I hope to get 35mpg without having to re-gear 5th. The rack/crossbars are going to stay on a little while longer (they are a PITA to remove, and I'm not certain if I'm going to use them for my bike yet). Stay tuned, fellow penny pinchers!

[niky]

I say go for the 5th gear swap. It's cheap and the benefits are pretty good. Probably even better if you can get a junked 626 tranny out of the bone-pickers.

A good header could help lean things out and improve MPG a little more, but most of the good ones are out-of-production already, and all that's left are the generic Taiwanese and OBX ones.

The P5 is a great car. Absolutely fantastic to drive. The short 5th and the odd 1st-2nd gap are perhaps its only practical foibles.

[MetroMPG]

Welcome to the forum.

Ditch the roof rack. Do not put a bike up there! Stick it inside the car (it's a station wagon!), or get a rear rack so the bike can ride (mostly) in the vehicle's wake where it's going to have a smaller effect.

Sounds like you're considering ditching the sunroof deflector as well. Good idea. Full time aero penalty for what percentage of actual use?

A thought: propping the rear of the hood may intuitively seem like it will help exhaust air from the engine bay, but the cowl area is a zone of high pressure. You may not be getting the results you're after there.

[SoCalMP5]

Originally Posted by niky

I say go for the 5th gear swap. It's cheap and the benefits are pretty good. Probably even better if you can get a junked 626 tranny out of the bone-pickers.

A good header could help lean things out and improve MPG a little more, but most of the good ones are out-of-production already, and all that's left are the generic Taiwanese and OBX ones.

The P5 is a great car. Absolutely fantastic to drive. The short 5th and the odd 1st-2nd gap are perhaps its only practical foibles.

Sounds like you know the car pretty well! I'm pretty happy with it overall. Ideal size, decent efficiency, and a nimble chassis. I'll do the 5th gear at some point, but all the research I've done says it only goes from 7.55 to 7.17 - so it doesn't seem like a huge change. Though, every little bit helps! I'm just knocking out the less labor intensive things first!

I may pick up an OBX header...I had their downpipe on a turbo Volvo and it was actually very good quality for the money. Good fit, nice welds, low price. I just hope it doesn't affect engine note too badly - I want this to stay the "quiet" car! I'm leaving the rest of the exhaust stock...I can't stand a car that sounds "fast" and can hardly get out of it's own way. lol.

Originally Posted by MetroMPG

Welcome to the forum.

Ditch the roof rack. Do not put a bike up there! Stick it inside the car (it's a station wagon!), or get a rear rack so the bike can ride (mostly) in the vehicle's wake where it's going to have a smaller effect.

Sounds like you're considering ditching the sunroof deflector as well. Good idea. Full time aero penalty for what percentage of actual use?

A thought: propping the rear of the hood may intuitively seem like it will help exhaust air from the engine bay, but the cowl area is a zone of high pressure. You may not be getting the results you're after there.

I ordered the caps to delete the crossbars; removing the sunroof baffle may prove a little harder. It attaches via metal brackets and I didn't look closely yet, but it appears those brackets are going to be a PITA to remove (much like the roof rails...to remove those, you have to take out a bunch of interior trim, remove the headliner, and unbolt the rails from inside the car).

The hood vent I can see working...it's really just so heat can escape to keep underhood temps under control, since I'm loading the radiator a little more heavily now. But you can see the heat escaping from the gap, especially after long periods of idle (stop and go, red lights). Ideally I'd do a grill in the hood (a la 300ZX), but it's a lot of work with cutting the hood and all...the spacers took me 5 minutes.

Coolant temps are good so far - 195 to 208. It hasn't been too hot lately though. We'll see what happens when summer hits! I'm jonesing for that elusive 35mpg...it's just gonna take some time, I can only afford maybe 1 mod per month! I'm sure some of you know how that is though. haha. Thanks for the notes guys...more to come!

[niky]

My Protege analogue is a license-made Ford model sold only in Australia and South Asia. Sedan variant with a five-speed. Decent economy when stock, except for the fact that it revs too high at 60 mph... but I've ruined her with racing bits (including some awfully aggressive cams) and a propane conversion.

These are cars you just have to love to bits. Even the owner of TrueDelta (that car reliability site) drives a P5.

Good luck eco-modding her. I think these cars have lots of untapped potential, merely from stock-to-stock parts swaps.

[SoCalMP5]

Originally Posted by niky

My Protege analogue is a license-made Ford model sold only in Australia and South Asia. Sedan variant with a five-speed. Decent economy when stock, except for the fact that it revs too high at 60 mph... but I've ruined her with racing bits (including some awfully aggressive cams) and a propane conversion.

These are cars you just have to love to bits. Even the owner of TrueDelta (that car reliability site) drives a P5.

Good luck eco-modding her. I think these cars have lots of untapped potential, merely from stock-to-stock parts swaps.

Thanks bud!

Is yours a 2.0 as well? We get the FS-DE here. About the only cams I hear of people using are Corksport or the FS-ZE Sport 20 cams. Are there other options for the FS-DE over there? I feel bad for the guys trying to mod this engine for performance...the highest N/A HP I've seen is around 120 wheel.

I already have my toy car - and while I was tempted to mod this for performance, I quickly changed my mind after seeing the results. lol. May as well go for MPG's!

[niky]

I'm using American-made Integral Cams, Stage 2. The supposed best were "Twiggy Cams", but production was very limited. Integral makes THE most aggressive cams for the FS, but only a fool would try to use the Stage 2.5 or Stage 3 in a street motor.

My car made about 151 whp before we dialled it back to 148 whp (with cam gears) to get some low end torque back. In the 151 whp trim, it was pretty useless since it made less power than stock below 5000 rpm. Stock on this same dyno is around 113 whp for the supposedly 142 bhp variant of the FS-DE.

I don't know what the Corksport cams are, but if they're the same as the FS-ZE cams, they're not very useful. Good for a 5 hp bump, maybe, so not worth the money. The Integrals were good for a whopping 15 hp difference.

If you're into eco-modding, forget them... my fuel economy went down the drain with these cams. I'm still trying to source a set of FP-DE cams from the 1.8 to see if they fit... will be a fascinating experiment...

[straight5]

I have liked those P5s since they first came out - but never owned one. And Volvo... I love my 850 - now with 329k.
So what Volvo do you have?

Also, the area where the windshield and hood meet, becomes a high pressure area when moving. So yea, I'm sure you can see heat rising from it when you're sitting still. As long as temps don't rise while you're moving, I don't know why it would be a problem.

[taco]

My sister had a Protegé5 automatic. Dad and I went to canton oh and bought it. I remember cause we took my es300. And the Lexus got 30mpg and the Mazda 29mpg on that trip . She averaged about 26-27mpg out of it. Do not put a bigger/ straight through exhaust on it. It kill all low end power. Was a nice little car. Loved to rev lol well was geared low She now has 2013Cx-5 awd that gets 29-32 mpg out of. Kinda crazy that the cuv gets better mpg than the wagon.

[rollercoaster]

Originally Posted by niky

I say go for the 5th gear swap. It's cheap and the benefits are pretty good. Probably even better if you can get a junked 626 tranny out of the bone-pickers.

How big of a job is this? Would the mazdaspeed6 6 speed be a viable alternative?

I am not enthusiastic to tear into a perfectly operating 5 speed. -but it is going to need a clutch soon after 100K...So "while i'm in there" ...