6g75 hp variations question

[trevroar]

Curious to why there's a hp different between 2007 Mitsu Galants GTS and Eclipse GT equipped with the same 6g75.

Eclipse

Power (SAE net): 263 bhp @ 5750 rpm
Torque (SAE net): 260 lb-ft @ 4500 rpm

Galant

Power (SAE net): 230 bhp @ 5250 rpm
Torque (SAE net): 250 lb-ft @ 4000 rpm

My thinking is that the Eclipse is enhanced with a more aggressive tune than the Galant from the factory. I would assume that all else is identical internally, as well as exhaust flow.

Just wondering since the donor car for my v6 swap is from a Galant.

[dejectedangle]

Different rpm ratings the lower the rpm the lower the hp!!!!!! I think

[pat_08GT_Spyder]

different ECU programming, probably...
the Galant is a family car, the Eclipse is a sports car :cough cough:

headers / exhaust might be slightly different too, air intake maybe... look at how much more power we can get out of the 6G75 with just exhaust / intake... same idea...

[fox_brand]

the 9g Galant (the regular none Ralliart version) doesn't have MIVEC, this is the primary reason why the 9g Galant has less power, the eclipse motor can put out more power up top as when MIVEC is engaged, it switches to a hotter set of cams (more lift, more duration), the factory tune has little to do with the power between the two

[pat_08GT_Spyder]

there you go, 3 answers and only 1 guy knows what he's talking about
that actually makes sense if the Galant doesnt have the Mivec booster

[trevroar]

I'll have to double check the webpage I was looking at, but I believe that was with mivec.

[trevroar]

Originally Posted by fox_brand

the 9g Galant (the regular none Ralliart version) doesn't have MIVEC, this is the primary reason why the 9g Galant has less power, the eclipse motor can put out more power up top as when MIVEC is engaged, it switches to a hotter set of cams (more lift, more duration), the factory tune has little to do with the power between the two

Yep, the GTS Galant is the non mivec, and only the ralliart is.. I got it now

[trevroar]

Originally Posted by pat_08GT_Spyder

there you go, 3 answers and only 1 guy knows what he's talking about
that actually makes sense if the Galant doesnt have the Mivec booster

Well to be fair fox_brand does drive a Galant

[fox_brand]

true, but I don't drive a 9g (those are 2004+), I'm one of the cross platform guys (like SPD_FRK) so I have a good bit of knowledge with cross compatibility, this sort of stuff is discussed in detail on club3g and two different galant forums in great detail, I can get you guys several links to threads about swapping in 6g75/74's if your curious

just for kicks, here's the differences between the cylinder heads at just the surface
the MIVEC

the non-MIVEC

note the difference in the shape of the ports as well as the non-MIVEC engine doesn't use coil on plug ignition

courtisy of:
http://www.galanttuners.com/index.php/topic,521.0.html

[SPD_FRK]

Originally Posted by pat_08GT_Spyder

different ECU programming, probably...
the Galant is a family car, the Eclipse is a sports car :cough cough:

headers / exhaust might be slightly different too, air intake maybe... look at how much more power we can get out of the 6G75 with just exhaust / intake... same idea...

ECU tune settings are what makes the most noticeable power output changes. This is well documented on the 3rd Gen Eclipse and 8th Gen Galants. The Eclipse tuning has more aggressive timing and better fuel maps to cater towards performance which is to be expected from the "sports version" of the same engine.

The Galant, both 4 and 6 cylinder engines are identical to the Eclipse (With the Eclipse GTS being excluded simply due to intake manifold difference), the Galant has a much more conservative tune set in place for fuel economy. The Galant GTZ model has a bit more aggressive tuning in place though.

Originally Posted by fox_brand

note the difference in the shape of the ports as well as the non-MIVEC engine doesn't use coil on plug ignition

courtisy of:
6g74 4.0L Stroker Information

The shape of the ports is nothing more than additional machining work. The Non-MIVEC heads can be easily port matched to the MIVEC ports. Also, not sure where you got your information about the coil on plug ignition system, but both the MIVEC and Non-MIVEC engines use the Coil On Plug ignition...look at the pictures you even posted...the mounts are clear as day on the Non-MIVEC engine.

[JoeyC]

[QUOTE=pat_08GT_Spyder;602961]different ECU programming, probably...
the Galant is a family car, the Eclipse is a sports car :cough cough:
QUOTE]

[fox_brand]

The shape of the ports is nothing more than additional machining work. The Non-MIVEC heads can be easily port matched to the MIVEC ports. Also, not sure where you got your information about the coil on plug ignition system, but both the MIVEC and Non-MIVEC engines use the Coil On Plug ignition...look at the pictures you even posted...the mounts are clear as day on the Non-MIVEC engine.

I was just about to edit my post to cover that fact, though thanks for the correction

I was going to change the last part of the post to
'note: the none MIVEC pictured has been fitted with 6g74/6g72 type vavle covers to allow for the use of a distributer as this engine has been swapped into 3g Eclipse/8g Galant platform vehical'

[SPD_FRK]

Originally Posted by fox_brand

I was just about to edit my post to cover that fact, though thanks for the correction

I was going to change the last part of the post to
'note: the none MIVEC pictured has been fitted with 6g74/6g72 type vavle covers to allow for the use of a distributer as this engine has been swapped into 3g Eclipse/8g Galant platform vehical'

The Non-MIVEC engine has the Non-MIVEC valve covers on it...they have not been changed with 72 or 74 valve covers. As I stated before, you can clearly see the COP mounts on the valve covers in both of the pictures you posted. You don't change valve covers to run the distributor on the 3rd Gen Eclipse or the 8th Gen Galant. I get that you are trying to help people out...but be damn sure you give the right information to people.

[fox_brand]

ok, my bad, I didn't see the bolts

[majin]

the ralliart 9G galant is rated at 258hp @ 5750rpm mainly due to the 63mm TB vs the 65mm from the Eclipse GT. The 2009+ Eclipse has 265hp @ 5750rpm due to the dual exhaust setup. The 6G75 Mivec should use a bigger plenum on the intake manifold to support the breathing charactistics of this engine.

[SPD_FRK]

Originally Posted by majin

the ralliart 9G galant is rated at 258hp @ 5750rpm mainly due to the 63mm TB vs the 65mm from the Eclipse GT. The 2009+ Eclipse has 265hp @ 5750rpm due to the dual exhaust setup. The 6G75 Mivec should use a bigger plenum on the intake manifold to support the breathing charactistics of this engine.

Actually the Eclipse GT and Galant use the same size throttle bodies. I have one from my donor 6g75 from a Galant that was compared to the Eclipse.