GV 2.5V6 - why so much less kW than comparable motors?

[grazza]

So I was reading the other thread on the price of the V6 and it was mentioned that the Mazda 2.5L V6 gets 169kW stock as opposed to the GV's 116kW.
They are both DOHC 24-valve motors so I was wondering if there was a fundamental difference internally in these engines which could explain it. Any engine gurus out there?

I suppose I am hoping that there is a simple reason which may help bring forth those missing kW If the motors are very similar perhaps getting a piggy-back computer and custom tune up done, maybe using Altronics or Motec (I know, mega $$) type things...

Maybe the Mazda is just a lot better motor, factory standard.

[cj]

Compression ratios, cam profiles, VVT, computer tune, exhaust, etc.

[MightyMouse]

A little history... Mazda and Suzuki designed the 2.5ltr V6 originally as a partnership, however as Mazda were interested in transverse mounting and Suzuki in North/South they went there own ways in the engine front covers. Thats why the Suzuki variant has ( had ? ) the troublesome cam drives and the Mazda didn't.

The two engines power output were initially similar, with Suzuki opting for a bit more torque ( as befits a 4WD ) and Mazda a bit more top end power ( for a road car ).

However thats where the Suzuki development pretty much stopped whereas Mazda kept developing the engine over the years - to the point where now NONE of the parts between Suzuki and Mazda are interchangable.

The Mazda version has gear driven cams, different timing, manifolds head profiles, pistons etc etc.... ( as listed by cj! ) However being sympathetic to Suzuki the Mazda engine is much "revier" as you would expect for a performance road engine.

The Mazda V6 is a great engine - very well designed and constructed and with limited demand isn't very expensive BUT its developed so far to be virtually unusable outside a Front Wheel Drive Application... for example the starter motor doesn't mount on the engine its on the bell housing - hanging over the gearbox.

So your question is VERY relevant seeing as they started of the same

[grazza]

Thanks for that MM. Very informative.

I expect there was little reason for Suzuki to develop the motor given its market. I guess thats also why there is little aftermarket support for better performance.

Performance and Suzuki (cars) dont really go together (which is a shame given their bike-tech)

[spamwell]

the mazda may be better performance wise but seeing as everything is manufactured by fomoco you get reliability issues and horrible oil leaks, watch a mazda tech run when a tribute comes in lol. they are evil.

sam

[murcod]

The Australian version of the Mazda 2.5l V6 (as fitted to the early to mid 90's 626/ Telstar) didn't produce 169kW. It was 121kW for a 1996 626 SDX according to Redbook.

The high output version was never sold here and is a Jap import engine. I know a few guys on OzMazdaClub have fitted them to their 626's etc.

[spamwell]

way different to the tribute

that 2.5 was the kl motor the tribute motor is the gy motor

come to think of it i thought tribuites where 3.0

and a 2.4 4 cyl LF motor

[murcod]

Yes, the Tribute is a 3l V6 - most likely from the Duratec family?

I owned a Duratec engined vehicle (2.5l V6, 125kW) and it was a way more sophisticated engine than the H27A in my XL-7..... I'd gladly swap engines to any Ford Duratec V6 if it was an easy conversion.

[MightyMouse]

The Australian version of the Mazda 2.5l V6 (as fitted to the early to mid 90's 626/ Telstar) didn't produce 169kW. It was 121kW for a 1996 626 SDX according to Redbook.

The high output version was never sold here and is a Jap import engine.

All true, but thats' not really the point - it shows what the engine is easily capable of - and what Suzuki might have achieved, probably for a whole host of reasons that made good sense to them.

The Mazda is still very drivable at that state of tune so it wasn't a sacrifice everything for power exercise either.

[murcod]

The Mazda is still very drivable at that state of tune so it wasn't a sacrifice everything for power exercise either.

You've driven one- and in a heavy 4WD? The torque curve probably isn't as suitable for 4WD purposes.

[MightyMouse]

Driven one in a sedan - yes.

At one stage I was considering one for a possible engine swap or Suzuki V6 modernization - spent a lot of time measuring externals and internals - but not to be.....

Vehicle weights were pretty comparable ( lots of bling on the sedan ) but as I said earlier the layout of the engine means that a North/South application would be a very significant project - and there turned out to be more compatible options.

So whilst I'm convinced that it would work well from a performance perspective - this is from the published curves of the relevant engines at the sort of RPM i was targeting.

I'm not suggesting its suitable for a 3 ton cruiser....

[murcod]

What do they rev out like? My H27A isn't the sort of engine that you rev out just for the thrill of it- it's noisy and not in a nice sounding way!

Weight wise I was thinking along the lines of XL-7 weight (~1900kg). I doubt any 626 would be getting up near that weight unloaded?