I did a write up on D-Series NA performance. If you read it, there is stuff that you can do but in my opinion it really is not worth the work or the money. These cars are cheap and the motors are as well. If you blow one up, you can just go get another one. I’ve seen them online for as low as $700 for low mileage examples.
If I would move forward with a D-series Honda, I would go
straight for a turbo kit. I may even go
straight for an ebay turbo kit and just run that till the motor blew, if it
ever did. I’ve seen some dyno charts on
stock d series motors running mild boost (8psi) and power up around 170HP. That is a pretty nice bump in power for not
too much money. Power for dollar, the
turbo kit is the way to go since it would be cheaper to just run that than to
try and get that power NA. You would
have spent more money going NA and still would not have those gains.
At this point you can just stop with the D-Series
performance. Turbo is the way to go, and
if you’re on a budget, just turbo the stock motor and be happy with your 170HP
Honda that doesn’t weigh anything. But
You can do all the other upgrades that you do to the NA motor build to the turbo build and get some serious HP out of that motor. It’s actually quite unbelievable.
Cams are where you can get some serious gains in this build. They are fairly inexpensive and you can see quite a bump in power on the turbo build. Researching some of the manufacturers of camshafts there seems to be a trend that the companies start at stage 2 for the turbo cam. Either way, if you check this site you will see some comparisons on the performance of the camshafts. These tests were performed on a fully built motor with a completed bottom end, but the percentages of HP increases remain consistent for the performance part being tested. It seems that the camshaft will get you at least a 10% increase in power that will put that 170HP turbo motor at 187HP. Now we’re getting somewhere.
You can continue down the road and do the turbo equilvilent upgrades as in the NA performance article and you will see those percentage increases. They will look a lot nicer on the turbo motor since the boost gives you more power to start with, with the higher HP comes more actual HP from the upgrades, but the percentages will be similar.
To start and get some real power from these motors, you will
want to build the bottom end. A common
upgrade to the bottom end is to change out the pistons to the Vitara
pistons. These are actually from a
different vehicle, the Suzuki Vitara. What
these pistons will do is lower the compression ratio from the common 9.x:1 to
7.8/8:1 depending on the application.
Lower the compression you say?
Well, lowering the compression allows you to crank up the boost with a
little bit more insurance, not having to worry so much about detonation and
grenading your motor (not as much).
Once you get here you may as well upgrade the connecting rods as well for additional insurance. With this upgrade, the pistons as well as the connecting rods, you are pretty much rebuilding the bottom end and strengthening it up for as much power as you wish. You will need to start looking at what the parts you are choosing are rated for, paying attention to the HP rating so that you are not purchasing parts that will not withstand whatever you are about to throw at it. I’ve seen dyno sheets out on the internet with single cam d-series motors making close to 500HP, the sky is the limit. These are affordable and really pretty reliable motors to boost and have some serious fun.
I think if I were to build one of these, it would have the
bottom end built and be running 11-15psi of boost putting the power output
around 300. Not too bad for a little
If you think about it, the turbo kit ($1000+/-), cam ($400),
and bottom end ($500 – if you do it yourself), plus another $500 in fuel
upgrades and tuning and we’re talking less than $3000 for a 300HP Honda which
will most likely be pretty reliable and fast as hell. This is definitely a build option.