You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
HC pistons from corksport
- Thread starter birdy85
- Start date
Glowspeedp5
Member
- :
- 2002 Mazda Protege5
If you know somebody at the dealer it is possible... You hook the MP3 to the computer first. Do an ecu read function.... Its takes about 15 minutes... All the data comes to the screen... Some of the variables are adjustable with the Mazda computer......save data.. then with the Protege5 next to the MP3 you connect to protege5 under the hood then click set prameters then click yes boom 15 to 20 minutes done... Ecu reflashed.........
Glowspeedp5
Member
- :
- 2002 Mazda Protege5
igdrasil said:I dont know the exact compression ratio...I will get them to be measured...but im sure is HIGHER!
Hey if you are using from a 1995 BP motor protege. Then the turbo guys can use the pistons from a 1991 SOHC 1.8 Bp motor. Those pistons make the SOHC motor 8.0 to 1 which is great for psi increase on the turbo.......
flat_black
Member
Actually, the SOHC and DOHC motors probably both have different deck height and probably different volumes on the head, so compression is a hard-to-call thing... Any Mazda F/B series piston using an 83mm bore would presumably work, though not always with the stock pins and whatnot. However, if you are talking in comparison, the BP's in the Protege's of the second generation, as well as the new FS/FP engines all have 9.1:1 compression ratio; No higher than stock. The SOHC BP of the first gens, though, had 8.9:1 compression... The .2 probably wouldn't make too much of a difference, though, for those running turbos. The 2001 and later BP engines in the Miata's had a ratio of 10:1, I beleive, though.
Wanna be the guy who does this for us? Finding an MP3 around here to begin with is a pain, much less a dealer that would be willing to do this!Glowspeedp5 said:If you know somebody at the dealer it is possible... You hook the MP3 to the computer first. Do an ecu read function.... Its takes about 15 minutes... All the data comes to the screen... Some of the variables are adjustable with the Mazda computer......save data.. then with the Protege5 next to the MP3 you connect to protege5 under the hood then click set prameters then click yes boom 15 to 20 minutes done... Ecu reflashed.........
The FS and BP pistons aren't interchangable. The FS has a 19mm wrist pin, the BP has 20mm.
Jamie, the book, "How to Build Horsepower" by David Vizard also states similar gains with compression ratios. Leaving everything else equal, changing compression in itself isn't a huge power gainer for small engines. Sure, if you're making 400hp from a big-block Chevy, and you up the compression, you're gonna make bigger gains. But since we're all in the low 100s, a 4-8% difference isn't much. But raising compression to 12:1 to take advantage of 280 degree cams, that's where you're gonna get power.
The Miata 10:1 pistons are $70/each CDN, and it's $120 for the ring kit. So for less than $500 after taxes(maybe 350US), I'll have my piston kit. Needless to say, I'll lighten them and balance them too....
read this peeps...there's not alot interchangable between the FS and BP
http://members.aol.com/solomiata/MX5Engine.html
Jamie, the book, "How to Build Horsepower" by David Vizard also states similar gains with compression ratios. Leaving everything else equal, changing compression in itself isn't a huge power gainer for small engines. Sure, if you're making 400hp from a big-block Chevy, and you up the compression, you're gonna make bigger gains. But since we're all in the low 100s, a 4-8% difference isn't much. But raising compression to 12:1 to take advantage of 280 degree cams, that's where you're gonna get power.
The Miata 10:1 pistons are $70/each CDN, and it's $120 for the ring kit. So for less than $500 after taxes(maybe 350US), I'll have my piston kit. Needless to say, I'll lighten them and balance them too....
read this peeps...there's not alot interchangable between the FS and BP
http://members.aol.com/solomiata/MX5Engine.html
SOHC pistons in the BP are good for 8.2:1 compression. I don't understand why someone would want to do this though, since the BP is made to handle plenty of boost to begin with.flat_black said:Actually, the SOHC and DOHC motors probably both have different deck height and probably different volumes on the head, so compression is a hard-to-call thing... Any Mazda F/B series piston using an 83mm bore would presumably work, though not always with the stock pins and whatnot. However, if you are talking in comparison, the BP's in the Protege's of the second generation, as well as the new FS/FP engines all have 9.1:1 compression ratio; No higher than stock. The SOHC BP of the first gens, though, had 8.9:1 compression... The .2 probably wouldn't make too much of a difference, though, for those running turbos. The 2001 and later BP engines in the Miata's had a ratio of 10:1, I beleive, though.
If you need custom rods, what's the point of doing a cost cutting mod like BP pistons? Full floating pins could work too, but not 1mm worth of float. And also, you don't know what the deck hight will be once installed. I have no experience with custom pins, since everything I've used in the past has been spec, but I'd like to know how you put 20mm pin in a rod designed for 19mm. I'm not sure I'd want to machine 1mm off the FS rods....
I'm not saying this is impossible, but it's not going to be a drop-in kind of thing.
I'm not saying this is impossible, but it's not going to be a drop-in kind of thing.
Last edited:
We will try this the in the upcomming weeks....so ill let you know.Gen1GT said:If you need custom rods, what's the point of doing a cost cutting mod like BP pistons? Full floating pins could work too, but not 1mm worth of float. And also, you don't know what the deck hight will be once installed. I have no experience with custom pins, since everything I've used in the past has been spec, but I'd like to know how you put 20mm pin in a rod designed for 19mm. I'm not sure I'd want to machine 1mm off the FS rods....
I'm not saying this is impossible, but it's not going to be a drop-in kind of thing.
twilightprotege
Member
- :
- 2001 323 Astina SP20 (P5)
shinzen - dont forget with the j-spec engine, the majority of the power comes from the ecu.
Installshield 2
Gothenburg Superiority
also note...It is not rated at 170 SAE Bhp, it is rated at 170 PS...which is similar to Europes DIN bhp rating...In the end the FS-ZE has a SAE bhp closer to roughly 163...just to clear up the numbers...
True on both accounts for the hp rating- but 163 is still 33 hp more than we have stock. On the ecu, this is only speculation on my part, but even with one of the AEM standalones installed, we still only pick up about 10whp, which would put it around 143 to the crank- The ecu has to be a large part of it, but the more agressive cams, better flowing intake manifold, and higher compression pistons must play a large part as well- Seeing this setup with something like the mpi tuner should pull around the same kind of power I would imagine- and thats without additional supporting mods or even more agressive cams.... Just a thought.
twilightprotege
Member
- :
- 2001 323 Astina SP20 (P5)
would be good if someone could test to see if the bp pistons will fit in the fs. would be very very very handy!
With custom rods, it'll definitely be no problem. The FS is a taller block, so the deck height with the BP pistons would be higher. Solution: longer rods, which DEFINITELY would be a good thing for the FS. Also, with custom rods, you can just make the small end diameter 20mm straight from the shop. Throw in them Miata 10:1 pistons, and you got an engine ready to rev with it's higher rod ratio and strong rods.
you can use the same rod from the older protege...the thing is that you will need to cut either the crankshaft or the rod to fit. I cant remember exactly right now, but we measured it on the FS motor and we know some modifications will be needed.
But I must say...both the piston and rod from this older protege are beefier than ours...
But I must say...both the piston and rod from this older protege are beefier than ours...
New Posts and Comments
- Replies
- 28
- Views
- 526
- Replies
- 595
- Views
- 196K
