I know what the differences are in the motors. Crank size and stroke, primarily.

My question is, in a quest for 400hp (or as close as i can get) vitara build, will I hit a wall with the D15?

(we'll say we're talking jdm d15b vs d16z6)

 

d-series.org

turbod16.com

you will find your answer there

 

The problem here isn't the pistons, its the rods. The stock D rods aren't good for more than about 220-240whp more often than not. Since the D15 has a different stroke than the desired D's, i dont think rods are available (at least as cheaply) as they are for the D16's

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Schister66 &raquo;</TD></TR><TR><TD CLASS="quote">The problem here isn't the pistons, its the rods. The stock D rods aren't good for more than about 220-240whp more often than not. Since the D15 has a different stroke than the desired D's, i dont think rods are available (at least as cheaply) as they are for the D16's</TD></TR></TABLE>

FJT has D15 rods designed for the average Vitara build.

I have yet to see a D15 go over 400 yet, infact, I haven't seen one do over 300 yet. Not to say they can't, they're just that uncommon.

 

Honestly, this is ur solution IMO:

http://fjdistributors.com/prod...d=285

everyone raves about them. Just my .02

Good Luck with the build man.

 

I havnt seen many d15's reach that either, id say the z6 easy. I did a vitara z6 build check my sig, and message me if you need any help

 

Lets look at it another way: I've never seen a D16 fail due to the less optimal rod/stroke ratio. Its marginal at best between the two, and you need all the displacement you can get (unless you're bisimoto).

The other issue is the D15 with 'normal' rods will yeild a much lower than normal CR with vitaras, which is already poor with D16's. You can go with the fjt rods, but for the same price you can get his D16 rods that give you a better R/S ratio in addition to bringing the CR up a tad. One more issue is the head & tranny. W/o lots of added parts in the head or better gearing, the higher theoretical RPM's are next to useless.

D16 &gt; D15 &gt; D14 (EDM)

 

brian crower is the only company i know of that makes rods for the d15...

 

http://fjdistributors.com/product_in...roducts_id=271