88 crx si a6/y8 mini me questions

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raceinspiredrex

New Member
i've settled on doing a y8 mini me head swap for the time being. i just have a few questions about what parts i'll need for the swap. for now, i'm just going to use an apexi vafc to activate vtec since my buddy's just going to give it to me.

i was told that my a6 intake manifold is better for upper rpm power while the y8 manifold is better for lower rpm power, can anybody verify this?

i was also told that i'll need a fuel pressure regulator and fuel rail from the y8 car too. is this true?

and what i'm also concerned with is what parts do i need exactly for the water pump, timing belt, and timing belt tensioner? i've heard people talking about what to use but nobody was very clear. they just said try this, try this, try this. so i figured i'd ask all of you for exact answers. thanks a lot everybody!
 
I know you may have your mind set on this and believe me I was the exact same way a year ago.

The proper way to manage your car is to not use a piggyback system such as V-AFC, but to use the proper ECU. Since the single cam VTEC engines first came out in the next generation car after yours you have to convert the OBD (on board diagnostics) status from OBD0 (yours) to OBD1 to run the proper ECU. Just useing a piggyback system won't get the full potentional out of a mini-me swap and it will harm the engine because it won't supply the proper timing and fuel maps for your engine.

In order to properly use a OBD1 ECU you need a 4-wire o2 sensor and the distributor for that engine. A D16Y8 head is OBD2 and it it to complex to convert it from OBD0. Most people use the D16Z6 head because its OBD1 and much easier to conver from OBD0. So if you use a D16Y8 head the OBD1 D16Z6 distributor won't bolt straight up, but it will fit if you cut the "ears" and put big washers on it.
 
I know you may have your mind set on this and believe me I was the exact same way a year ago.



So if you use a D16Y8 head the OBD1 D16Z6 distributor won't bolt straight up, but it will fit if you cut the "ears" and put big washers on it.


You dont have to use a vtec distributor for vtec to work. For a obd1 conversion and a Y8 head use the 92-95 Civic DX. Youll be fine that way. Itll bolt up perfect, and vtec will still work perfectly fine.
 
The D16A6 intake manifold will bolt straight up and the D16Y8 manifold does flow a bit better. The whole A6 manifold is all you need, no different fuel rails or anything.

You will need a D16Z6 or D16Y8 timing belt though because its 3 "teeth" shorter than the D16A6 one. Things like the water pump, timing belt tensioner, ect. are only maintenance recomandations but still needed if its due.
 
You dont have to use a vtec distributor for vtec to work. For a obd1 conversion and a Y8 head use the 92-95 Civic DX. Youll be fine that way. Itll bolt up perfect, and vtec will still work perfectly fine.
I've never heard of that before but I always thought it had to be a VTEC dizzy but I guess that makes sence.
 
you don't have to purchase another dizzy or do anything fancy. the a6 dizzy bolts right to the y8 head. every bolt lines up
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for the belt you need one from a d15b7 out of a 92-95 civic dx/lx
 
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you don't have to purchase another dizzy or do anything fancy. the a6 dizzy bolts right to the y8 head. every bolt lines up
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for the belt you need one from a d15b7 out of a 92-95 civic dx/lx
But with the A6 dizzy you can't run the P28 ECU which he needs. I don't know about the B7 belt but the Z6 and Y8 belts work fine for shoure.
 
i was hearing conflicting info but i suppose that makes sense. the diz has to match the ecu. as far as the belt goes the z6 and y8 belt are the same, 104 teeth, 1" width, 39" length. neither of them work. i used the z6 one on my a6/y8 setup, and it was just a tad too long. it would flex back and forth while it ran and rub up against the driverside engine post bracket.
 
i was hearing conflicting info but i suppose that makes sense. the diz has to match the ecu. as far as the belt goes the z6 and y8 belt are the same, 104 teeth, 1" width, 39" length. neither of them work. i used the z6 one on my a6/y8 setup, and it was just a tad too long. it would flex back and forth while it ran and rub up against the driverside engine post bracket.
Well I don't know about the A6/Y8 setup but I know on a A6/Z6 setup its ok.
 
i'm just doing a cheap mini me swap for now using whatever i have. this isn't going to be super long term. i don't want to convert to obd1 right now. i want to use the y8 head with my current obd0 dizzy. has anybody else done this exactly?

or would it be best to convert to obd1 with a rywire kit, a p28, z6 head, and z6 dizzy?

i'm just trying to figure out what would be cheapier and easiest to do, yet give me the most power. the best bang for the buck you could say. please let me know. thanks a lot
 
i'm just doing a cheap mini me swap for now using whatever i have. this isn't going to be super long term. i don't want to convert to obd1 right now. i want to use the y8 head with my current obd0 dizzy. has anybody else done this exactly?

or would it be best to convert to obd1 with a rywire kit, a p28, z6 head, and z6 dizzy?

i'm just trying to figure out what would be cheapier and easiest to do, yet give me the most power. the best bang for the buck you could say. please let me know. thanks a lot
Well a Z6 head is older than a Y8 so it will be cheaper to buy.

You can just slap a SOHC VTEC head on (Z6, Y8) to OBD0 and no VTEC and run your car under 4000 RPM. If you're going to spend money on a swap you might as well do it the right way the first time so you don't have to spend unnecessary money.

If you know around a engine bay a bit you could do it the right way pretty cheap.

A OBD0 to OBD1 conversion harness off of eBay is $75. I got a good running Z6 head for $200. I got a dizzy and o2 sensor for $30. Head gasket and timing belt $60.

Then after that the conversion harness will come with instructions and you will add six wires from the harness to the engine bay.

A VTEC ECU puts more fuel into the engine when VTEC is engaged. A V-AFC won't do that. You won't notice a difference between that and your stock Si. Also a V-AFC won't adjust the timing and do the VTEC maps such as a P28 ECU would. V-AFCs are designed for cars that already have VTEC to change the RPM engagement of VTEC. The unit itself can't tell a non-VTEC ECU to add fuel and change the timing.

Thats the way I understand it. Please do correct me if I'm wrong.



Doing it the right was isn't the easiest, but it has the most "bang for your buck".:)
 
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i understand that, so that should settle it, i talked to another guy locally too. i think i'm going to go obd1 and swap over the ecu and dizzy also. if i'm going to do it, i should completely do it the right way. and he said i might as well just screw around with sohc for awhile too and learn the ropes a little bit, i agreed lol.

so if i'm using the z6 head, p28 ecu, z6 dizzy, and obd0 to obd1 conversion harness, what else will i need? i was told i'll need the z6 fuel pressure regulator and possibly fuel rail. i was also told that i might need an adjustable cam gear. does anybody know about these for sure?

and if i'm doing the z6 head on my a6 block, exactly what would i use for timing belt, tensioner, and water pump? thanks a lot everybody!!
 
i was hearing conflicting info but i suppose that makes sense. the diz has to match the ecu. as far as the belt goes the z6 and y8 belt are the same, 104 teeth, 1" width, 39" length. neither of them work. i used the z6 one on my a6/y8 setup, and it was just a tad too long. it would flex back and forth while it ran and rub up against the driverside engine post bracket.


Mini Me timing belt rule....Use the belt that matches the head. Y7&A6 mini mes can use the stock belt.
 
so if i'm using the z6 head, p28 ecu, z6 dizzy, and obd0 to obd1 conversion harness, what else will i need? i was told i'll need the z6 fuel pressure regulator and possibly fuel rail. i was also told that i might need an adjustable cam gear. does anybody know about these for sure?

and if i'm doing the z6 head on my a6 block, exactly what would i use for timing belt, tensioner, and water pump? thanks a lot everybody!!

anybody? so i need to use the z6 head gasket and timing belt, but what about the tensioner and water pump? use the same ones from the a6?

and also, what do i need exactly with the harness? i know i need the jumper harness and distributor adapters, but what about hooking up vtec? let me know guys. thanks
 
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anybody? so i need to use the z6 head gasket and timing belt, but what about the tensioner and water pump? use the same ones from the a6?

and also, what do i need exactly with the harness? i know i need the jumper harness and distributor adapters, but what about hooking up vtec? let me know guys. thanks
The tensioner and water pump are on your stock block so you use the the stock D16A6 parts.

You also need a 4-wire oxygen sensor off of the D16Z6. The P28 ECU won't reconize the 1-wire stock one.
 
i appreciate the info, thanks a lot for that.

i still need to know about the harnesses though. EXACTLY what do i need for that? i would like everything to be plug and play, including vtec. is any of that possible? thanks again
 
This is the OBD0 to OBD1 conversion harness I got: ECU Conversion Jumper Harness Pre OBD0 to OBD1 EG DC - (eBay.ca item 120339667206 end time 27-Nov-08 21:15:06 EST)

As you can see in the picture there are 12 wires that lead off. You only need 6 wires of the 12. The other ones are for different motors. Don't cut the extra wires because if your Mini-Me is only temporary you may need the extra wires for your next motor swap. So lead the 6 wires through a hole in the firewall and the instructions will tell you what wire goes where.

4 wires go to the 4-wire oxygen sensor and 2 wires go to VTEC. There are 3 wires on the VTEC solenoid on the head and one is a ground (thats why you only need 2 wires).

For the dizzy you will have to go to an auto wrecker and cut off the plugs from a 92-95 Civic EX/Si and cut the old dizzy plugs off of your harness and solder/heatshrink the newer dizzy plugs on.
 
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very informative. thanks so much!! i plan on just making or just buying the distributor adapter harness/plugs.

is there anything else is should look out for or anything else i should know at all?

thanks a lot everybody
 
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