D15B vs D15Z1

[Ecky]

Is everything 100% hooked up? I don't suppose VTEC is engaging like it should, is it?

[drmiller100]

si trans is pretty low geared I believe. Probably about what you should expect for mileage from that engine.

[Viceral]

Originally Posted by Ecky

Is everything 100% hooked up? I don't suppose VTEC is engaging like it should, is it?

There pretty much is no Vtec at the moment. I hooked the 12 to 16 valve switchover to a switch, but without the ecu, the lean burn doesn't activate at all yet. I usually keep it at the 12 valve setting and have had no problems with acceleration or power even at highway speeds. If anything, the car is actually more fun than it was with the SI in it.

[Viceral]

Originally Posted by drmiller100

si trans is pretty low geared I believe. Probably about what you should expect for mileage from that engine.

I don't know how it compares to other transmissions, but I know it has the highest gearing of any of the CRXs by quite a bit. That's a big part of why I'm debating throwing in the HF tranny. With the lower gearing I should be able to keep the RPMs lower and maintain lean burn longer (once the new ecu is chipped and installed), even at highway speeds. Right now in 5th gear 50 mph is the fastest I can go while keeping it under 2500 rpm, and typically I drive quite a bit faster than that.

[drmiller100]

low geared means it revs high.

There are a LOT of people who want your SI trans - you can probably find someone who will do the swap for you.

[Viceral]

Originally Posted by drmiller100

low geared means it revs high.

There are a LOT of people who want your SI trans - you can probably find someone who will do the swap for you.

Haha oh my bad.

[Ryland]

With and HF transmission you should be going 65mph with the engine spinning 2,000rpm or so and that engine should have enough power to keep that car at 30mph in 5th gear with an HF transmission on a flat road.

[B16vtek]

I have alot of experiance with hondas. I had a DX crx, sold it to get a 98 DX civic hatch. Anyways. You dont need vtec, or to ever worry about it or hook it up. They say you need to hit it every 5000 miles or so so it doesnt gunk up the vtec oil passage. but! if you dont ever want vtec (and lower gas milage) then dont hook it up. You motor still has more power than a stock si without it.

The HF or DX tranny is what you want for gas millage, or a 5th gear swap from one. The HF is better. I dont see any reason why you wouldnt be getting 45-50 mpg combined after a tranny or 5th gear swap.

Again this is just my 2 cents

[Viceral]

Originally Posted by B16vtek

I have alot of experiance with hondas. I had a DX crx, sold it to get a 98 DX civic hatch. Anyways. You dont need vtec, or to ever worry about it or hook it up. They say you need to hit it every 5000 miles or so so it doesnt gunk up the vtec oil passage. but! if you dont ever want vtec (and lower gas milage) then dont hook it up. You motor still has more power than a stock si without it.

The HF or DX tranny is what you want for gas millage, or a 5th gear swap from one. The HF is better. I dont see any reason why you wouldnt be getting 45-50 mpg combined after a tranny or 5th gear swap.

Again this is just my 2 cents

Yea, that is what I was thinking. Would it be better to swap the whole tranny or just the 5th gear? I feel like the tranny would be easier to do if it was all the same.

[Viceral]

Although I do plan to at least hook up the vtec E properly.