Poor Hp/L of BP series engines

[irwin83r]

if you find some torque figures and interesting statistics could you please post them up?

i think the reason the mx5 has stayed where it is performance wise is mainly marketing, the mx5 isnt mazda's soul performance car.. it is marketed as a fun convertible, which it is.

in any case the motors are strong, good wearing and have enough poke to have some fun, especialy with some minor mods, though that applies to most motors from factory.

what motor is mazda's main performance motor?? would that be the rotors?

[PT]

What about the FE3? From the late 80's early 90's? Common conversion for the MX6 guys to rip out the 2.2L SOHC 12v and put in the DOHC 16 2.0L FE3

[STV]

i hate to say it, but in my humble opinion...

they should have put something similar to the Toyota 4AGE 20 Valve.

I believe for a 1.6 that put out approx 118with no tricky cams, no VTEC, VVTi, or any other accronyms or forced induction.
I have wondered if anyone has ever brought up the blasphemous topic of transplanting the above mentiioned engine into an mx-5... I think that would have made even the early versions (which i still own and LOVE) into a bit of a weapon straight out of the showroom...
Just my ramblings..
Cheers
Steve

[Russellb]

Was thinking of putting the Toyota 4AG-ZE engine in the old mans NA6
a few years ago but now have gone down the Custom autorotor route

[JSE]

My mate has a stock standard 200SX S15 (2.0L Turbo 151kw at fly)...and he was shocked that my little 1.6L could keep up with him and actually pull away so much faaster out of corners...After first driving my Roadster I thought the engine was very very soft with no power...but after comparing it to a few of my mates cars I really am surprised.

If you ask me Mazda was spot on with creating the BP series...just enough power and grunt needed without the consumption of litres and litres of fuel.

[Moggy]

As someone said earlier the engines date from the 80's and are originally out of 323's. Mazda obviously didn't want to design a new engine for the mx5 for cost purposes and had the B6 and BP series engines that were the most appropriate in their line up to fit.

They are good solid engines however and they will handle reasonable power with the addition of a turbo. Also not much power is needed to make an mx5 go fast as they are so light. Add turbo, computer and exhaust and you have a 12 sec car that still handles superbly. Not many people want more than that in their car. The BP's in stock form will never come close to an atmo Honda engine though as these were designed to be high revving (9000 rpm), high compression, variable valve timing engines and are a lot more recent in design.

[Sean]

i hate to say it, but in my humble opinion...

they should have put something similar to the Toyota 4AGE 20 Valve.

I believe for a 1.6 that put out approx 118with no tricky cams, no VTEC, VVTi, or any other accronyms or forced induction.
I have wondered if anyone has ever brought up the blasphemous topic of transplanting the above mentiioned engine into an mx-5... I think that would have made even the early versions (which i still own and LOVE) into a bit of a weapon straight out of the showroom...
Just my ramblings..
Cheers
Steve

thats what I was thinking. OK I admit it I have a 4AGE RWD 20 valve, and it goes real well. I do think that putting one of these in a MX-5 would be a good conversion, I bet it would be alot lighter too.

Problem is that by the time you fabricate engine mounts, bell housing adapter and pay miscellaneous costs like wiring and engineering etc, you are well and truly past the cost of building up a great BP or B6 engine that will by far outperform the toyota.

[Babalouie]

thats what I was thinking. OK I admit it I have a 4AGE RWD 20 valve, and it goes real well. I do think that putting one of these in a MX-5 would be a good conversion, I bet it would be alot lighter too.

Well, I dunno if there would be that much in it weight-wise, since the 4AGE is iron-blocked too. But a 20V puts out around 82rwkw and most NBs will put out at least that much with a few simple mods. The BP does release quite a bit of power when modified since it's quite understressed in stock form.

I reckon the 4AGE's strong bottom end would be better for a 9000rpm, quad throttled, mega-dolalr motor, but for mild mods I would say that the BP is actually a better bang for the buck option...

[STV]

the 4AGE's strong bottom end would be better for a 9000rpm, quad throttled, mega-dolalr motor,

But the 20V is ALREADY quad throttle bodied, so, if talking about spending a few bucks more on mods, imagine what that would then be capable of.

i vaugely remember reading about a dude who created a 4AGZE 20V with a 1.8 bottom end, i imagine that would be about the pinicle of its developement.

Not that i am bagging the 1.6/1.8 donk in the mx-5, personally, i think mine goes plenty quick for me
cheers

[Babalouie]

i vaugely remember reading about a dude who created a 4AGZE 20V with a 1.8 bottom end, i imagine that would be about the pinicle of its developement.

Yeah, that's a not-uncommon conversion called a 5AGE, using the 1.8 block from the later Corollas, but mated to an earlier 16V or 20V head.

[Brian]

Having had a number of 4AGEs and BPs my comments are that we need to compare the same timeframes etc:

The 89 B6 should be compared to the 4AGE 16V (big port) Out of the Twin Cam corolla and Series 1 MR2

B6 85Kw 130NM
4AGE 86KW 136NM

Very little difference but the 4AGE has a slight torque advantage.

Then compare the 93 BP to the 91 4AGE 16V small port from Corolla GTi

BP 98KW 155NM
4AGE 98K 146NM

Again very little difference although now the BP has the torque advantage.

The 4AGE 20V again comes in two versions Silver top 106KW and Black top 112KW I don't have the torque figures.

However the 2000 BP with Variable valve timing has 113KW and 181NM

Having said all that you can get more power out of the Toyotas than you can the Mazda engines for less money.

My 7AGE(1.8 7A bottom enge 20V head) produced 136rwKW compared to the worked and stroked BP gettiung 120rwKW. This was still on the standard quad trottle bodies with a standard 7A bottom end!!

The toyota is a more freely reving engine and feels nicer to drive than the BP but the BP has more torque and should not be underestimated.

Cheers

Brian

[Matty]

i recon if toyota put out a replica of the mx5 with the 20v it would sell tonnes of em.

People, don't forget that Honda tried something similar - it's called the S2000. It's hardly a runaway sales success...

Face it - Mazda got it right, and they continue to nail the niche.

[STV]

i think that the S2K shouldnt really be compared to the MX as although it is a 2 seat drop top, the pure price difference puts it more around the catagory of a much higher end sports car.
the mazda engineers DID get it right, the sales figures prove that, PLUS they need to make the thing drivable by the lowest common denominator driver... AKA the person just got their license and decided that they want a sports car today.
that person couldnt exactly go and get a porche etc with the sort money to pay for an mx.

i dont think that anyone is bagging the BP or the MX at all, just fantasising about it with a more powerful engine. that is simply what car freaks and DRIVERS do..

Cheers
Steve

[Babalouie]

i recon if toyota put out a replica of the mx5 with the 20v it would sell tonnes of em.

People, don't forget that Honda tried something similar - it's called the S2000. It's hardly a runaway sales success...

Face it - Mazda got it right, and they continue to nail the niche.

From memory, the original Bob Hall proposal for the MX5, and also the initial prototype, had a live axle, and was powered by a carby'd SOHC 1.4 engine pilfered from the RWD 323.

So in actual fact, the NA MX5 we did get was heaps and heaps more sophisticated and high-performing than the actual concept It was supposed to be a modern MGB, a rwd roadster that was super-cheap because it was mechanically simple!

[Matty]

i think that the S2K shouldnt really be compared to the MX as although it is a 2 seat drop top, the pure price difference puts it more around the catagory of a much higher end sports car.

If the MX-5 had S2000 power levels, it would have been priced similarly, so the comparison is not just valid, but the entire point. Power output is the cause of the price, not the result...

I'm not stressed that people want more power (hell, I do), just that they think that the original product should have been delivered that way. If it had been, it would have been priced accordingly, and would have sold in far fewer numbers, killing its popularity as a cheap used car.