questions about going Forged

:
20
Hey guys, I have some questions about forged internals... and before everyone gets angry and tells me to search, let me tell you I have. All I'm really wondering is, how much gain would you see from installing forged? The reason I ask, is because I'm hitting 217K in miles and I'm just trying to plan for the future. Ideally I'd love to throw a nice boxer engine or mz3 , but that could create issues and I'm not looking for a race car... just something with more power ;). Anyways sorry to blabber but, I was just wondering if there would be noticeable gains if I went the route of the speed circuit forged engine or just started buying piece by piece... hey thanks!
 
what are you trying to accomplish here?

It all depends on what you want to do with your engine. The fact that the parts are forged wont give you any gains at all. It'll just make sure the engine is strong enough to handle the power its making safely. Whether that is done by forced induction, head work, and bolt ons.

If you sticking to NA you don't need to go forged at all, even though it would help with reliability, you just need to raise the compression ration which can be done with FSZE pistons, and/or milling down the head.

If you go speedcircut i believe they use low compression pistons for forced induction, if you aren't running forced induction through that engine you'll a have power lose compared to the stock engine.
 
Last edited:
Oh great! Thank you so much, i was just trying to stick NA and go the bolt ons route. I more or less was wondering if there would be noticeable gains from the bolt ons with the forged parts. I also thought that I had seen that they offer two different forged engines, one with the stock compression and one running a little different for a lower psi on forced induction.
 
Last edited:
With high compression pistons, cams, full exhaust, head work, intake and mp3 Ecu you will be looking at ~150 whp with a standalone you might be able to get 160-170 whp. Stock rods are good for 220-250 whp depending on tune which no na fsde will ever see. They also do not hold up well to nitrous iirc only one person has used it successfully and it was only a 50 shot

The fsde is worthless for na power the record with super high compression pistons and custom cams and a standalone was 197 and it didn't make any power till 6000 rpms.

The mz3 motors are drive by wire and would take a pointless amount of time money and aggravation to make it work. The only good option for a swap is the kl motors
 
I don't think there's much point in going forged unless you plan on boosting it. Just put on your bolt on parts and save the difference.
 
Go have a read of installshields thread. Alot of the stuff there is rather complex but you will have a better understanding of how engines work and how they make power. These engines aren't useless at making power its just people's attitudes and sheep whom give them a bad rep. Soon as you do headwork and cams these engines open right up :)

You can make plenty of power from an NA engine. Its not about the peak figure its about the area under the curve, flat linear power band.

Prolly wont feel as fast but that's not really the point is it :)

Also tweety you forgot the part that it had bugger all tune time before being strapped to the dyno (an hr or two). It didn't make any power till 6k rpm yet it made 199ish at 8k rpm? Power curve must have been damn near vertical then huh...

@OP, take a look at buying an FS-ZE will be far cheaper then a turbo build or an NA build. And this some boltons will be good for ~140hp at the wheels will have a nice power band too.
 
It's been awhile since I looked at install shields thread I forgot or didn't know about the no time for tuning part. I do remember him saying how peaky it was and wasn't really drivable

And if you do comparison of motors that aren't an fs you will quickly see how worthless it is. All motor 1.8 Honda motor can easily make 300 whp and 250 ftlbs. I literally watched a friend of mines get dynod onsaturday. I'd love to see an fs do that. Fsze isn't worth the money for 30ish hp. Not to mention a lot of people with them have pinging issues

Klze on the other hand, 200 chp stock with no mods
 
It's been awhile since I looked at install shields thread I forgot or didn't know about the no time for tuning part. I do remember him saying how peaky it was and wasn't really drivable

And if you do comparison of motors that aren't an fs you will quickly see how worthless it is. All motor 1.8 Honda motor can easily make 300 whp and 250 ftlbs. I literally watched a friend of mines get dynod onsaturday. I'd love to see an fs do that. Fsze isn't worth the money for 30ish hp. Not to mention a lot of people with them have pinging issues

Klze on the other hand, 200 chp stock with no mods

Oh I agree there not stellar NA engines. But there not hopeless, we just don't have the epic head design that late 90s early 00's Hondas had. But we also don't have the advantage of VTEC to help with low speed (which use similiar profiles to our car stock) and high speed (which use cams like installshield except with 10-12mm lift) drive ability so we without becoming peaky like Installshield can't rev high enough to make that power. I'd love to see a 300whp FS as well but I dont think anyone here has the dollars that would have been thrown at that honda. And if someone did it would be a b**** to drive as it'd be peaky.

But by the same token our engines aren't any worse then the other engines out there. FP engines are just as good as BP for making power, granted we don't have the same aftermarket. The only engines that the FP/FS dont stack up against are engines that were designed to rev and rev. (B18 (honda), F20 (honda), K20(honda), 2zz-ge(yamaha), 4age Silver/Black top (yamaha)) So yes in comparison to the holy grail of NA engines they dont make a heap of power, but in comparison to other cars they are of similiar characteristics/limitations.

In regards to FS-ZE i agree straight off the bat, but OPs engine has high miles. Going in any direction significantly is going to be a strain. So swapping in an FS-ZE which tend to come from Japan with about 40-90k kilometres (not miles) on the clock. Is a solid start.

And yeah, KL-ZE and FE the two decent engines NA engines that mazda produced (at least that used pistons)
 
Like i said, fast isn't exactly the point :) I'm just trying to get a little more throttle response and have enough power to make it up hills without chugging. I drive from the city back home, to the hills and 40% of the drive is up canyons. I've replaced plugs and wires lots and I'm just not satisfied, so I'm just trying to problem solve and plan. So to make sure I'm picking up what you guys are throwin down, If I were to get the fs-ze, forged pistons would be recommended based on my desired results. Different cams and head work would also be recommended to support it as well, if I plan to stay NA and just use bolt on's? I'll go have a look at that thread as soon as I'm off work today! I don't think I'd consider rotary as much, I feel like they're intimidating hah, but has anyone swapped a rotary engine into a p5 before?
 
I think an engine swap is overboard when you could just build/boost an FSDE. A KL or FZ is about the only pioneered swap I can think of off hand. You might try going the NA bolt on route and see how you like it. If you don't you can sell most of the parts off for most of what you have in them.
 
Like i said, fast isn't exactly the point :) I'm just trying to get a little more throttle response and have enough power to make it up hills without chugging. I drive from the city back home, to the hills and 40% of the drive is up canyons. I've replaced plugs and wires lots and I'm just not satisfied, so I'm just trying to problem solve and plan. So to make sure I'm picking up what you guys are throwin down, If I were to get the fs-ze, forged pistons would be recommended based on my desired results. Different cams and head work would also be recommended to support it as well, if I plan to stay NA and just use bolt on's? I'll go have a look at that thread as soon as I'm off work today! I don't think I'd consider rotary as much, I feel like they're intimidating hah, but has anyone swapped a rotary engine into a p5 before?

Then you need to look into TORQUE gains, not horsepower specifically. Horesepower is great and much necessary to go fast, but toruw is what gets you going.

Here are some things that will help you accelerate more: (things i have on my to do list as a matter of fact.)

Lower center of MASS

Increase wheel/ tire size, i think even sidewall radius matters when talking torque.

Lighten your car (weight wise, dont go paint your s*** white)

Lastly...Change gear ratios.

Now, if you have a cat. converter still take it off, not only is it way heavier than a header but it does have some prety noticable restriction.

Removing the VTCS will give you the throtle response you get from flooring it, without having to. im guessing that MUST give you an accelaration boost.

However i have heard you lose power if you also remove the VICS, so id keep those in just in case.
 
Forged pistons wouldn't be needed with an FS-ZE.

If your after a more peppy engine and want to stay NA, get an exhaust, a 626 racing header. Those two mods will make the engine alot nicer to drive and give substantial benefits.

After that consider a Cold Air Intake and maybe an MP3 ECU. Will net you good gains.
 
Did he seriously ask about swapping in a rotary?

Just to condense everything here you have 4 basic options

1. Bolt ons ( intake, header, exhaust, mp3 Ecu) and be happy with it till you get a better platform

2. Go fsze or kl make a bit more power with the fsze or a good bit with the kl plus bolt ons

3. Boost it. Stock motor is good for ~250 whp with supporting mods which is enough power to have a lot of fun with

4. If its an auto do a manual swap, you're looking at a 25-40 whp gain just from that plus better gas milage

Choose one and go with it. But just some advise if you want a little more now you will get a little more get used to it and want more. I was happy with my 323 at 12 psi, then got bored and bumped it to 18 was fun for awhile but then I got bored again. Now I'm going with a bigger turbo and going for another 100 whp

And don't say you're looking for a little bit more throttle response and extra power to get up hills, we all know where that one is going. We all know the car is way underpowered
 
It was more of a question, since he mentioned certain engines being the best that Mazda made with pistons. So it was more of a question out of curiosity, than an option. I don't think I know what you mean by, "we all know where that one is going." Comment. I'm just asking questions to find out the results and options for when this cars engine gives out. So that when it does i have an idea of what I'm doing instead of slamming a bunch of research in and making bad decisions and later regretting it..
 
626 header will swap straight on.

If you want more power now then the list of mods tweety and myself have listed will be good. And if you swap to a FS-ZE will carry over with no problems (cept maybe ECU im aussie so no experience with MP3 ecus, could work well or not at all.)
 
If you're just looking for more throttle response, just basic bolt-ons could get you a small bit, albeit - small means minimal.

The KL swap is no small feat - it's pretty involved - but the rewards are plentiful (especially when you boost the v6.. :) ).
I'm not "in the know" about the FS-ZE swap, but I'd imagine there are a few hurdles to clear that could be answered from this board.
 
The only difficult part of the fsze swap is fitting the fsze intake manifold. That's where all the power comes from. I know someone locally who recently swaped the fsze intake manifold and got it working without throwing a code. Gotta say feels much more peppy than the stock fsde.
 

New Threads and Articles

Back