3times

Just as title states. Can any of the s4 13b components bolt onto my gsl-se engine to give some extra horses?(excluding the turbo of course)

Hyper4mance2k

iTrader: (40)

higher compression, lighter rotars, and more port timing.

nosferatu595

Check on the AFM. In the late 80's we would swap in a 86- on. Afm into the SE. Seems the later AFM was less restrictive and was a gain of 5-8 HP if I remember correctly. Has been a long time.

diabolical1

iTrader: (3)

actually the compression ratio is the same on the S3 and S4. however, yes, the rotors were like a pound and a half lighter.

the changes came from tweaks on the intake manifold setup and the change in the ignition system from distributor to CAS. all in all i think it netted like 11 HP and 5 ft-lbs (using factory specs).

Fire85GSLSE

iTrader: (29)

On my S3 motor, I used the s4 uim,lim,and tb and it made a huge difference.

The intakes are larger so you get more air. Also the S4 afm is larger and don't forget the s4 uses 4 injectors rather than 2 like the s3. Over all that is what makes up the difference.

85rotarypower

I think another thing that contributes to the increased power is the use of 4 injectors in the S4 engine as compared to only 2 on the S3 engine. May not have made a difference, but probably made a drivability difference.

steve84GS TII

As stated before,the intake manifold had a lot to do with it.The 2nd gen engine made more peak power,but lacked the SE's super lowend torque curve.The S4 also benefited from the powerful,direct,wasted spark ignition setup which is proven to be very capable,even at triple the factory HP.The staged fuel injection gave more precise control over fuel delivery,especially at lower engine speeds,where it was more difficult to meter the big injectors of the SE engine.The S4 also introduced the lighter,decreased friction 2MM apex seals.

Personally,I think the gruntier SE engine would have been more at home in the heavier FC chassis,but Mazda was probably trying to make the next generation's engine more zingy and responsive,to match the new,more advanced car it came in......

Rotor13B

I heard once you put a carb on either one there really is no difference.

diabolical1

iTrader: (3)

technically, with the exception of maybe an undiscernible engine rev response (due to the lighter rotors) there is no difference with carburetion. so you pretty much heard right.

Hyper4mance2k

iTrader: (40)

both enignes with carbs the s4 will have more peak hp, but less torque. The s4 had 10* more intake timming.