D15B vs D16Z6, HELP ME DECIDE!!!!

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Draftinwitjr3815

New Member
OK, so here is what I've got, my girl friends circle track car HAD a rebuilt D16Z6 engine, I built at the beginning of the season. Well the engine lasted just that, ONE season, last race, they threw the checkers and a rod went through the block. SO I now have a winter project!!! :D

OK so I've got a D15B sitting on the floor of my shop, I know NOTHING about the engine, its been sitting for 2 years, I plan to tear into it and rebuild it.

NOW, my track rules say we have to keep these engines built with OEM parts, no aftermarket B.S. so I have to be careful.

What I'm looking into is, will I be better of rebuilding another D16Z6 or the D15B I have? I know the D15B has a different stroke, but everything else seems pretty equal. We run a stock P28 ecu, and we can't chip it.

Also, I'm looking for an ANSWER to this quesiton:

I've read up on the D15B3 Carb'd Engine. 9.9-1 CR????? Can I use these pistons in either the D15B or D16Z6 if I can find some? Will it hurt or help??

Thanks in advanced!

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The JDM D15B uses shorter skirt pistons(27mm vs. 29-30mm found in other D15s, minus the Z1, and D16s). You can counter that by using modified B16A rods.

If you're going for power, then the D16Z6 is probably your best bet; especially if chipping is not allowed and more pistons to pick from(mainly just the P29/PM7 and PG6s).
 
OK, so what is the highest compression piston, (stock) that will fit into the z6 block?

You mentioned something about the Z1 up there^^ I also have a D15Z1 short block, anything I should hang on to, consider?
 
That would be either the P29/PM7(~12:1) or PG6(~11.7:1).

I should clarify, do you have a D15B VTEC?

The Z1 uses 137mm rods, which is the length on the D15B-V and D16s, but uses the regular smaller D15 BE diameter unlike the D15B which uses the D16 size. You can run the taller compression-height pistons on the D15Z1 by switching to regular D15 rods(whereas on the JDM D15B you'd need modified B16 rods or custom rods).

IIRC, the D15Z1 crankshaft is a little lighter but this is achieved by getting rid of some of the counterweights. Not good for a motor that'll rev high.
 
^ Couldn't have said it better, and the p28 runs fine for the d15b. If you want, a friend of mine 'purposely' threw his car itnto limp mode while auto-xing. He said the extra fuel would help low end tourque and stuff like that. I dont like it, but if you cant chip it maybe a ghetto way to modify fuel maps would be sufficent?
 
When my ECU was in limp mode, it wouldn't rev past 4000rpm and felt slow. I'm wondering why they don't allow chipping though; as it uses the stock ECU/parameters.

You could always switch to carbs, maybe? There's also changing fuel pressures, injectors, etc. The biggest difference I saw with the P08 maps and P28 was the ignition timing around part throttle. Fuel wasn't too different, could be easily compensated.
 
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Ok, so these P29 pistons, D16A1 correct? These will fit into the stock z6 block and on z6 rods, I wont have any clearencing issues?
 
I don't want to jack this at all but i got a question similar to this that hasn't been answered yet. I have a D16Z6 that I blew auto-xing and now im not sure if it would be best to just put another D16Z6 in or a mini me motor or D15B?:eek:

Im a collage student and am on a budget tighter then a straight guys ass.

I can get a D15B7 complete with tranny and head ready to drop in from a friend
for 400 bones. A D16Z6 is 795 without shipping. But I don't want to sacrafice performance because ones cheaper then the other.

remember this is for auto-xing and class doesnt matter I race myself every run...

any help would be great PM me or reply here but I don't want to jack this or anything. thank you for your time and a wonderful site! :D
 
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