matt965

I am just now getting my feet wet in engine mods. I don't want crazy power or bragging rights or anything though. Just learning some new stuff here.
If anyone on the EF side has been watching, you know of my https://honda-tech.com/forums/honda-...hatch-3287635/. I am rebuilding a 4-spd transmission and adding a 5th gear from a 1994 civic dx. My concern is that there will not be enough power to maintain a constant speed in 5th gear with this a6. I am going to rebuild the motor once the transmission is complete (it has 300k miles). Since I will have it torn apart, I can do swaps.

I want more power in the low end area, but any gains are small. Of course, staying in the low end involves changing the timing.
I also want to upgrade to have better acceleration with this tall-geared transmission. I do not want to turbo it.
So far I have considered these mods:
- pg6 pistons
- y8 head if I can make it work without vtec
- thinner head gasket (probably y8)
Running this through the compression calculator brings it to 12.2:1

I'm thinking of a cam upgrade as well, but some have said the a6 cam is good. What do you guys think of all this?

DumpdEJ6

I am not familiar with D-series modifications, but for low rpm grunt probably the best thing you could do is a longer stroke. Like I said, not very familiar with interchangeable parts in a D-series, but perhaps there is a longer stroke factory crank you could swap in?

matt965

D-Series Tech - High Compression Stroker - Honda Tuning Magazine
Something like that is pretty cool, but way too elaborate for my needs. Seems d17 internals is the only way to go for longer stroke though... I may just stick with the d15b1 since its peak torque is around 3000 rpm and I have a jdm b1 with supposedly less than 90k miles. Doing a few upgrades on that might be better in this situation.

I'd like to know why the peak torque is in the low range on the d15b1 and d15b6... Perhaps there's something I'm missing here.

v4lu3s

more stroke more compression and more displacement. you would probably need to develop your own cam or use a stock one for low end power, more air flow means more power and the fastest way to get more flow is more lift, more duration and more RPM.

matt965

I decided if any mods are done I will use pg6 pistons or maybe pistons from a mid 90s GX, I will use the b1 cam, and I will chip the ecu and use a fuel map similar to the b1.
This setup will probably provide the best results for me. I heard the y8 head has issues with oil starvation so I will stick with the a6 head. VTEC is over-rated anyway haha.