Natalee Rebuild Thread

[alpaccino]

Hi all, as with everyone on this forum, i have big plans for my car this year. The plan is to go boost this year and fall somewhere within 12's or 13's class. As stated earlier i'm just in the planing phaze and is currently doing some R&D's right now. I have never turboed an engine before an as such i have a ton of questions, my first question should be simple:

1) I cannot get the covetted b6t/bp/bpt here but only b5 dohc, which i just have to boost instead, so my question is, how can you know how much psi boost can a stock engine /b5 dohc safely handle? How can you also know the correct size/type turbo to use for the said engine?

The dyno showed me that i'm making 92.5 hp to the wheels so i want anywhere from 160 upwards and i'm fine.

Now my plans are to use Megasquirt ecu, Advance Suspension Mods esp the secret weapon traction mod also eyeing the water/methanol injection. I currently have the b5 dohc,2002 demio brakes at the front, b5 steal braided brake lines arround, b3 gear box (will change soon) and 185/60/13 wheels. Will provide pics shortly and throughout the project.

All suggestions are welcome

[bhearts]

Safety of an engine has the most to do with fuel quality. Water methanol is your best bet. Once you get that transmission upgraded you're pretty much good to go with a standalone ecu. I would personally get your tunable ecu tuned great on your n.a. setup, then the turbo can be added. Benefits of this are you can still drive the car once the turbo is installed. Most people choose a turbo from a similarly sized engine, so in your case shoot for oem from 1.6l to 1.8l.

[alpaccino]

Thanks bhearts, so basically with the water methanol set up and 90 octane regular pump gas 12-14psi good for this engine? I personally believe in getting the ecu working great on the na as well, so as to cut down on the different failure points

[bhearts]

Thanks bhearts, so basically with the water methanol set up and 90 octane regular pump gas 12-14psi good for this engine? I personally believe in getting the ecu working great on the na as well, so as to cut down on the different failure points

If you made sure you were tuned to 12.5 to 1 afr before you add that methanol, I don't see any reason why you wouldn't be ok at that boost level. If your engine is in good working condition. Get progressive water methanol controller. Add methanol enough to achieve some really rich afr. 11.5 to 1. But make sure it's tuned rich enough without it in case you run out mid pull.

[bhearts]

Thanks bhearts, so basically with the water methanol set up and 90 octane regular pump gas 12-14psi good for this engine? I personally believe in getting the ecu working great on the na as well, so as to cut down on the different failure points

I wouldn't really consider 14psi on a stock engine to be reliable boost. That sounds more like 8psi. But there's things that can be done to combat your engine prematurely ejectinga piston. Intercooled, tuned, water injection, premium fuel. It all helps

[Advancedynamix]

What car did your engine come out of. Is the head like a miata or more like a protege 1.5 dohc? I'm unfamiliar with the B5 DOHC. If it is simply a short stroke b6D then you're in luck. If it is like a Zlde you're even luckier. Stock internals in both those engines will support your goals with proper turbo system design and proper tuning. Take some detailed pictures of your engine, and we can help you plan your build. Also, if you can do some research on what they did to make it a 1.5, that would be great.

[moz]

B5 and b6 share same Pistons and rings, so the difference lies in rods, and crank. So yes, it's just a short stroke b6.

The sohc was available in the 1994-2000 aspire, db mazda 121, mazda 121 metro (demio), Kia Rio.
The dohc version was available in the Japanese mx3, early kia sephia (that's about it off the top of my head).

I've only seen the kia version and it look just like a b6d out of a cApri but with more modern valve cover

[alpaccino]

Engine Pics

[alpaccino]

More Engine bay pics



Pics of Natalee





Also to show how close the master cylinder is to the topics cover


I am trying to find a booster that can fit in that tight space, that's what you get when you go right hand drive lol


2001-2002 Mazda demio brake upgrade, 9.25 inch rotors

[bhazard]

I always thought that the B5 shared the bore spacing with the BP. Basically a de-stroked BP. They look similar enough.

Also didn't know Jamaica was right hand drive.

[Advancedynamix]

That looks like a BP. If a B5 is a destroked BP, then it may be the most bulletproof engine available. The BP is built like a tank, but suffers from some harmonic issues due to it's stroke length. With a shorter stroke, and all the same provisions, this engine could be quite potent. Is the crank forged like the BP?

[moz]

Natalee Rebuild Thread

I only know that b6 and b5 use the same rings and Pistons because the part # is the same for both

But THAT ^^^ looks like a BP to me.

[bhearts]

That looks like a BP. If a B5 is a destroked BP, then it may be the most bulletproof engine available. The BP is built like a tank, but suffers from some harmonic issues due to it's stroke length. With a shorter stroke, and all the same provisions, this engine could be quite potent. Is the crank forged like the BP?

Are you having b5 dreams?

[alpaccino]

according to wiki http://en.wikipedia.org/wiki/Mazda_B_engine
B5 Dohc 78 x 78.4mm
B6T 78 x 83.6 mm
BP 83 mm bore and 85 mm stroke

I love the idea of a bulletproof engine but it looks more like a destroked b6 to me, but i'm new to this, also not seeing where it says anything about forged crankshaft for the b5

[bhearts]

according to wiki http://en.wikipedia.org/wiki/Mazda_B_engine
B5 Dohc 78 x 78.4mm
B6T 78 x 83.6 mm
BP 83 mm bore and 85 mm stroke

I love the idea of a bulletproof engine but it looks more like a destroked b6 to me, but i'm new to this, also not seeing where it says anything about forged crankshaft for the b5

Nothing wrong with a shorter stroke. It should allow you higher revs compared to longer stoke counterparts with comparable components quality