Tom's B6 Build Thread

[TominMO]

B6 is sweet. This build is sweet. When I have money I still want some work done by Matt. If your 8v 1.6 feels that good, I can't imagine what the 16v would be like.

IIRC from what he was saying, the 8v B6 is the sweet spot of the B-series motors for making the most power inexpensively; i.e. it's a well-designed head, and there is only half the porting, valve and cam work to be done. And the 16v isn't going to give you radically-better flow numbers than the 8v. The stock B6 is 83 HP crank; the B6D is 100, and the B6 has more room to grow. With a 4-valve combustion chamber in the same bore size as the 2-valve, those two intake valves can't get a lot larger.

This is just my impression from memory; you might want to have a conversation with him about the flow rate potential of the B6D head, and decide if it's worth it.

[bhearts]

With only 5 PSI it probably wouldn't blow anyway. That would simplify things a bit to go low boost; but the power benefit at that level makes it seem not so worth the expense/complication. Especially since I would need to back off the timing for the sake of the turbo. Lose a little power to gain some more power. For example, B6D = 100 HP, B6T = 130. Meh.

Have you never heard of water methanol? Just a feeler though. You have the head built, the header, the exhaust is pretty. Screw the turbo, go S. I'm absolutely going to build a supercharger kit for my b3. With a boost controller, you should be able to adjust anywhere from 1 to max psi. Sure, you'll just a little more loss compared to a turbo, but you have the setup for a supercharger right there. Porting of the head allows you to run less boost to make the same power as an unmodified motor. Lowering the delta pressure across the charger makes a huge difference is parasitic loss. Check out this graph I found, lol.

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[TominMO]

I don't know too many people who do their own build and plan to stay at low boost who actually do... Its so much fun to just turn it up a little more and a little more

Yes indeedy.

[bhearts]

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[TominMO]

Have you never heard of water methanol? Just a feeler though. You have the head built, the header, the exhaust is pretty. Screw the turbo, go S. I'm absolutely going to build a supercharger kit for my b3. With a boost controller, you should be able to adjust anywhere from 1 to max psi. Sure, you'll just a little more loss compared to a turbo, but you have the setup for a supercharger right there. Porting of the head allows you to run less boost to make the same power as an unmodified motor. Lowering the delta pressure across the charger makes a huge difference is parasitic loss. Check out this graph I found, lol.

Sorry, too complex for my taste. I like to have an uncomplicated engine bay.

If I was to do anything, it would be a turbo connected to the header.
--Short oil and air return lines compared to rear turbo.
--Walbro in-tank pump instead of the inexpensive aux. fuel pump I had Greg use to save $$.
--No need for a pump to return the oil either, as with rear turbos. Oil would return from the turbo mounted on the rear of the header to the rear of the oil pan; very short and simple.

[sketchman]

Yeah, I know peak diff won't be that radical, but a 4v CC torque curve should be even flatter than a 2v CC all else being equal. Cause you get the same flow with less lift so velocity stays higher.

I know I can beat on my car just as much (if not more than) as when it was a 1.3 and I still get the same fuel economy with a bigger engine and more power.

Same ECU, same everything except the engine.

[TominMO]

Yeah, I know peak diff won't be that radical, but a 4v CC torque curve should be even flatter than a 2v CC all else being equal. Cause you get the same flow with less lift so velocity stays higher.

I know I can beat on my car just as much (if not more than) as when it was a 1.3 and I still get the same fuel economy with a bigger engine and more power.

Same ECU, same everything except the engine.

Mine's making plenty of torque down low, with this cam profile. Matt thinks this head makes more HP at 2000 RPM than stock peak power @ 5500 or so. His B3 was like that. We'll know more Friday.

[bhearts]

Is this the head one member was selling about a year ago

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[TominMO]

Is this the head one member was selling about a year ago

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No, I got this head out of a local JY.

[Advancedynamix]

IIRC from what he was saying, the 8v B6 is the sweet spot of the B-series motors for making the most power inexpensively; i.e. it's a well-designed head, and there is only half the porting, valve and cam work to be done. And the 16v isn't going to give you radically-better flow numbers than the 8v. The stock B6 is 83 HP crank; the B6D is 100, and the B6 has more room to grow. With a 4-valve combustion chamber in the same bore size as the 2-valve, those two intake valves can't get a lot larger.

This is just my impression from memory; you might want to have a conversation with him about the flow rate potential of the B6D head, and decide if it's worth it.

Interesting. I see a lot more flow potential in the 4 valve head, but I haven't had either on a bench. I do know that the un-ported b6d head will easily support 180hp n/a on 91 oct. Pump gas. I've pounded many a lap with just such an engine, and Dragonhealer has a pile of dyno graphs to support the claims, but I don't need those, my lap times were within 2 seconds of the track record for a miata without boost. Lol
Are you coming to Madness Tom? We could do a few freeway pulls with the b6 and the b6d. It would be pretty fair comparison except I'm just running a stock capri exhaust manifold and stock cams.
One thing is sure, the sohc intake manifold is superior to the b6d part. I'm convinced that Mazda detuned the b6d with the intake manifold, throttle body size and cam tuning. If you optimize those 3 things the b6 dohc engine really comes to life.
Either way, this is a great thread and I'm excited to see what your TQ curve looks like. What type of dyno will you be using for the test?

[navdoc101]

What's that saying? If you go B6, you'll never go back.....

[TominMO]

Interesting. I see a lot more flow potential in the 4 valve head, but I haven't had either on a bench. I do know that the un-ported b6d head will easily support 180hp n/a on 91 oct. Pump gas. I've pounded many a lap with just such an engine, and Dragonhealer has a pile of dyno graphs to support the claims, but I don't need those, my lap times were within 2 seconds of the track record for a miata without boost. Lol
Are you coming to Madness Tom? We could do a few freeway pulls with the b6 and the b6d. It would be pretty fair comparison except I'm just running a stock capri exhaust manifold and stock cams.
One thing is sure, the sohc intake manifold is superior to the b6d part. I'm convinced that Mazda detuned the b6d with the intake manifold, throttle body size and cam tuning. If you optimize those 3 things the b6 dohc engine really comes to life.
Either way, this is a great thread and I'm excited to see what your TQ curve looks like. What type of dyno will you be using for the test?

Not planning on coming to Madness this year, unfortunately. Would you consider a brief mini-meet in Memphis? I know you guys have a long haul, so if you don't want to schedule a stop there I understand. I mention Memphis because it's the closest point to STL on Hwy 40. It's 283 miles, so I should be able to make it in about two hours. ;-) A good location would be in Arkansas just west of Memphis, where 40 and 55 meet--Walmart Supercenter, grocery store, restaurants; exit 276.

The dyno is not a Mustang dyno, it's a Dynojet (don't know which model); which is ironic because this is specifically a Ford Mustang tuning shop (tho they will dyno anything). Personally, I expect about 135 WHP, not 145, because the intake hasn't had any flow work done to it, and is just a stock one, not a custom upper half like on his B3 head. Also, perhaps the optimal header tubing for this motor would be slightly larger than for the B3, but that would have to be tested. This tubing will give a higher flow rate of course, and I'm sure there is theory for what is best, at least in general--higher flow vs. higher volume. No doubt there is a sweet spot, and while this header is much better than the stock manifold, it may not be the optimal setup for this built B6 head.

Why don't you give Matt a call and discuss B6/B6D issues? With your areas of expertise and practical experience, I'm sure both of you would enjoy it. (260) 723-4584.

[Advancedynamix]

Yeah, a meet up in Memphis would be great. I'm not exactly sure of our timing yet though. We'll have to get rolling first to estimate when we'll be in Memphis. I have a tradition of getting fried catfish whenever I'm in memphis.
If everything goes as planned, we will have 3 versions of b6 swap with us. Stock b6, slightly modded b6d and stock B6t with water meth. I think 4 or more versions will make it B6-a-palooza, haha.

[TominMO]

Yeah, a meet up in Memphis would be great. I'm not exactly sure of our timing yet though. We'll have to get rolling first to estimate when we'll be in Memphis. I have a tradition of getting fried catfish whenever I'm in memphis.
If everything goes as planned, we will have 3 versions of b6 swap with us. Stock b6, slightly modded b6d and stock B6t with water meth. I think 4 or more versions will make it B6-a-palooza, haha.

What's your intended ETA in Raleigh?

[bhearts]

so you had the head hogged out like crazy, but your intake manifold is still factory porting? that sounds like a massive gasket mismatch to me. tons of room for improvement.