ECU Swapping.

[Matty49]

Ok, so I race on a short track and we are limited in what we can do with our cars. I have a 91 civic 'STD' so I have to swap the 4-speed for a 5-speed(as per the rules of the track), this is no big deal for me. But I have been told to swap the ECU for the PM6 of a Civic Si. Based on the information I've found the PM5 is the ECU in the car(I haven't ripped it down yet).
: Can I swap a PM6 ECU for a PM5 in an 91 Civic to get increases in power/torque? Or am I just out in left field?

 

[brian11to1]

I dont think you can do that without converting to MPFI. The STD model has no options and is DPFI. If you hooked up the PM6 I dont think it would run...

 

[phunky.buddha]

You can't just swap the ECUs. Your STD has 2 injectors, while the PM6 controls 4. You'll have to swap the intake manifolds to convert to MPFI to make the PM6 ECU work properly, and then you'll see a slight power increase.

From your other thread that I just locked, just changing the injectors to larger ones won't give you any more power unless you can get more air into the engine.

 

[Matty49]

Ok, knowing that more air is needed, and given the diference in the length of the stroke from a 1.5 to a 1.6 is 5.5mm is it possible to change the crank. Is there enough "room" to accommodate the extra stroke length within the block? Is the 1.6 crank actually longer than the 1.5 front to back etc.? Basically I need to find a way to juice it up even 5-10% for the extra little punch without changing the outer look of the engine. It has to look stock!

 

[brian11to1]

I dont think its the crank, i think the rods are different.

Why dont you swap out the pistons, bump the compression and conver tto MPFI/tune with turboedit and you'd be set.

either way you HAVE to convert to MPFI to gain anything.

 

[phunky.buddha]

Ok, knowing that more air is needed, and given the diference in the length of the stroke from a 1.5 to a 1.6 is 5.5mm is it possible to change the crank. Is there enough "room" to accommodate the extra stroke length within the block? Is the 1.6 crank actually longer than the 1.5 front to back etc.? Basically I need to find a way to juice it up even 5-10% for the extra little punch without changing the outer look of the engine. It has to look stock!

Nope, you can't change the crank. The main journals are different sizes. Well, I guess you could cut up two blocks and stuff the 1.6 guts and journals into a 1.5, but it's not worth the time and effort. As for crank length, they should be the same.

The best thing to do for another bit of power would be to increase your compression with some domed pistons, then run a different camshaft.

I dont think its the crank, i think the rods are different.

Why dont you swap out the pistons, bump the compression and conver tto MPFI/tune with turboedit and you'd be set.

either way you HAVE to convert to MPFI to gain anything.

The crank AND the rods are different. Changing rod length on its own doesn't do anything to change displacement.

 

[brian11to1]

I dont think its the crank, i think the rods are different.

Why dont you swap out the pistons, bump the compression and conver tto MPFI/tune with turboedit and you'd be set.

either way you HAVE to convert to MPFI to gain anything.

The crank AND the rods are different. Changing rod length on its own doesn't do anything to change displacement.

I dunno what I was thinkging, I shoulda realized that. I even looked at the engine chart we have.

I'm not to much into D series, but theres a shit load of info on d-series.org... Im sure they can get ya the power increase youre looking for.

 

[phunky.buddha]

Or he can stay here and read a bunch of posts I've written about the D too.

 

[brian11to1]

Or he can stay here and read a bunch of posts I've written about the D too.

Yea, sorry. I didnt know you had written a bunch of shit for the D. Either way, bumping compression and a more wild cam will get more power. Right? Right.

 

[phunky.buddha]

Yup, always.