Hey,

I will be swapping out my tired D15B7 (250,000miles) out of my EH2 for another, younger, more potent D-Series engine that will see boost in the near future. Only problem is, which one, or what combination of parts should I use? That is the question.

I've been researching and basically finding differences between the Z6 and Y8. Please keep in mind that my plan is to boost my engine in the near future (couple of months).

Here's what I've come up with so far:

y8 has stronger shift forks (steel) compared to the z6's (aluminum)
y8 has smaller combustion chambers, thus higher compression
z6 has a better flowing head
y8, I'd have to convert the motor to obd1, while with the z6 I wouldn't.

This leads me to belive that for my car (EG) I should use the z6 longblock and the y8 tranny. That way, I wouldn't have to convert it to obd1, I'd get the stronger tranny and better flowing head with a lower CR.

Can anyone advise otherwise, or fill in something I've missed?

Thanks.

 

yep
get the z6 just so you wont have to deal with obdI
I have a y8 tranny on my d15b,

everything else is just nitpicking, and nothing big enough to even notice.

basically, whichevers cheaper/easier is what you want.
the two motors are too similar to really trip over them.

 

Cool.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tad &raquo;</TD></TR><TR><TD CLASS="quote">yep
get the z6 just so you wont have to deal with obdI
I have a y8 tranny on my d15b,

everything else is just nitpicking, and nothing big enough to even notice.

basically, whichevers cheaper/easier is what you want.
the two motors are too similar to really trip over them.</TD></TR></TABLE>


You mean OBDII....I never had a problem with OBDII when I ran my y8 turbo setup.

 

Get the z6 motor, y8 tranny, and y8 headgasket.

 

Why the y8 headgasket?

 

What about an a6 block? I'm pretty sure you can just change over all the parts to make it obdI. And that has the highest compression out of the three I'm pretty sure.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by swifty4u &raquo;</TD></TR><TR><TD CLASS="quote">What about an a6 block? I'm pretty sure you can just change over all the parts to make it obdI. And that has the highest compression out of the three I'm pretty sure. </TD></TR></TABLE>
I'm boosting the engine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by litterbox &raquo;</TD></TR><TR><TD CLASS="quote">I'm boosting the engine.</TD></TR></TABLE>

on me. I was thinking of a buddy of mine, has that combo and is turbo. His car is just a full out race car though.

 

I have a y8 motor and tranney for sale as well as a turbo setup minus the BOV but it has the GReedy Type S flange on it

 

cause its metal 3 layer.

 

What year is the car, just making sure you know not to put an older engine into a newer car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by litterbox &raquo;</TD></TR><TR><TD CLASS="quote">Why the y8 headgasket?</TD></TR></TABLE>

2 layer metal gasket

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sohcvtec1995 &raquo;</TD></TR><TR><TD CLASS="quote">cause its metal 3 layer.</TD></TR></TABLE>

thought i was 2 layer ?

 

3

 

definatly easier to take the z6 motor and y8 tranny. then you really do get the best of both. plus with boost, you might want a little lower compression, but thats me. i believe keeping a OBD-I motor will make it easier to boost in the sense that you can get a Prom chip for it, and you only have one 02 sensor. Thats assuming you convert your car to OBD-II which i reccomend against.
Very nice, 250k miles on that underpowered motor, cool.

 

so the y8 gasket will fit no problem to the z6?

 

yes it will fit.

don't people usually do the Y8 intake manifold also?

 

yea the mani i heard about also

 

Well I'm definitely staying obd-1 (Z6) engine so I can tune with uberdata.

Is there proof that the y8 intake mani flows better than the z6? I've heard contradictary opinions.

 

z6 mani &gt; y8 mani

per dseries.org folk

everyone I've ever heard boast about the y8 mani have really had
no basis other than how it looks.

 

I'd just buy and boost whatever motor I find for cheaper, honestly.

A Y8 head may not as flow as well as a Z6 but I honestly could not tell a difference when i had a stock Z6 head as compared to a Y8 head.

And since you're boosting a D-series, I assume you want to save money.
So that means unless your building a crazy boost monster, both motors are absolutely fine. Find a low mileage, good condition motor for the best price and go for it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Br1anPham &raquo;</TD></TR><TR><TD CLASS="quote">
And since you're boosting a D-series, I assume you want to save money.
</TD></TR></TABLE>

I'm hoping to have a boosted D for $1500. Think it's possible?

 

haha, definetely quit nitpicking about what motor/tranny u want then

get whatevers cheapest!!

but yeah its definetely possible,
i've seen ppl build turbo kits for like 400 bucks,

But I wouldnt recommend skimping on important items like fuel management.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tad &raquo;</TD></TR><TR><TD CLASS="quote">haha, definetely quit nitpicking about what motor/tranny u want then

get whatevers cheapest!!

but yeah its definetely possible,
i've seen ppl build turbo kits for like 400 bucks,

But I wouldnt recommend skimping on important items like fuel management.</TD></TR></TABLE>

What he said. EXACTLY WHAT HE SAID.


HF manifold + 14b turbo is probably the one of the cheapest way to go. I

picked up a HF manifold at a junkyard for 20 bucks once.