On the rollers - a Mustang MD-1750




Well, there's still work to do...... after all day on the dyno, the numbers aren't very good - and confirmed my butt gauge. Even considering this was a Mustang dyno that gives conservative real-world numbers compared to other dynos and factors in everything including vehicle weight, wind resistance and atmospheric conditions, I think the numbers tell me I need to make a cam change.... either revert to the Montero cams or advance the Diamante cams a bunch. What power there is available is up top, not enough and really doesn't put it where it needs to be for a truck.

When you factor in the powertrain losses, I'm above OE specs, but late getting there. Anybody want to guess how much HP and torque is lost through the drivetrain on a 3.0L with 32" tires? I don't think it's as much as I'm missing. This is the last pull for today:



That's 121.4HP @ 4962rpms and 141.4TQ @ 4081rpms at the rollers.... the graph shows 117/137 weather factored.

I would expect maybe 50HP max to go out the driveline, but that's a guess. I've never seen a HP/TQ graph look like that. <img src="/forums/images/graemlins/scared.gif" alt="" />

Charlie, I have the MSQ if you want to see it..... we were never able to get the engine to spark knock and began to lose power if we advanced it too far. That seems like I could use some more cylinder pressure.

Frank

In the early 90s one of the 4X4 mags dyno ran all their tests. The Mighty Max pulled 135Hp with a 5 speed and a Montero was 130 with auto. I have no clue what the dyno was. A Nissan was high 120s and the Toyota V6 was under 100Hp.

Sounds like the heads work, you should be able to drive on regular, 87 or 98 Oct. I run my 4G63 turbos on 87 with 14Lbs boost. No issues.

I need to install Mega tune but then I can look over your numbers.

Can you up the drive ratio on the blower?

I have a 2.6" pulley on the blower now and it turns the blower pretty close to redline. A smaller blower pulley would likely be difficult to keep from slipping.

What would work would be a larger crank pulley and redline the engine at say 5200rpms..... but I don't think a larger crank pulley would work with the timing indicator on the front cover. Also, that fix would put me into boost much sooner and I'm already getting into it too often for my preference.

Some of the driving impression is because it's been so long since I drove the truck, I've forgotten how much I needed a couple of pounds of boost on hills. I'm now driving it faster on the highway (75-80) than before because of where the engine seems to breathe, but I'm getting fairly deep into boost to climb grades. It might help to lower the transmission shift points, but I had hoped to avoid the constant downshifts with more torque so I could stay in O/D longer.... it does, but I think I've sacrificed something on the bottom and would like to trade off some upper end.

Frank

Sounds like a lot of work for not much in return to me. Not knocking your build at all its bad <img src="/forums/images/graemlins/butwiggle.gif" alt="" />. But I would of done a 4.3 swap.

A 4.3 swap ain't a piece-o-cake, either - just ask those who have done them..... or go ahead and do your own. <img src="/forums/images/graemlins/wink.gif" alt="" />

I don't know of many Gen1s that can highway cruise at 80+mph on 32s..... in O/D..... but I ain't finished yet. <img src="/forums/images/graemlins/wink.gif" alt="" />

Frank

Yes. But you are getting away from this Mitsu <img src="/forums/images/graemlins/ignore.gif" alt="" />. And into the world of readily available parts. Ok i'm done hi-jacking. Looking good Frank.

You just don't understand that it can still be tuned on, and it's basically dial a boost. Want more HP... ok pully swap, and gain 40-50 . <img src="/forums/images/graemlins/kewl.gif" alt="" />

Sometimes the end result is only part of the equation. Overcoming the seemingly endless obstacles & sucessfully diving into previously uncharted territory can create as much satisfaction as finally acheiving the desired results does. A 4.3 conversion is probably an easier project, but I'd personally rather be standing next to a custom supercharged V6 that I designed, fabricated & built when someone says "wow, you did that yourself?"

Frank, my hat's off to you. <img src="/forums/images/graemlins/patriot.gif" alt="" /> I look forward to reading about your progress every time I log on and have huge amounts of respect for your perseverance & skill. I'm even more grateful that you are sharing the whole project with the rest of us in the interest of expanding the common knowledge base.

<img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" />

Thanks, fellas - <img src="/forums/images/graemlins/kewl.gif" alt="" />

I'm wearing out Texas Instruments calculators tonight trying to figure out if it would be better to advance the Diamante cams or swap back to the Montero cams. <img src="/forums/images/graemlins/lol.gif" alt="" />

If my math is correct, the longer duration Diamante cams have the same lobe separation angle as the Montero cams at 110*, so there's no LSA advantage to be gained from either cam. The Diamante cams do have 4* more duration with a trade-off of 4* more overlap. Again, if my math is correct, the Montero cams have 38* overlap and the Diamante cams have 42* of overlap. Feel free to check the math.... if I didn't calculate it correctly, I'd like to know.

Here's my guess - and it's really a guess - why I'm not getting what I expected:

1) the later closing intake valve with the Diamante cam starts compression with a lower volume of mixture, has a shorter effective compression stroke, is not building as much cylinder pressure as the Montero cam and therefore there is less power is in the available mixture.

2) the added valve overlap is leaking combustibles out the exhaust.

The only way I know to find out for sure is to make the swap, but I sure don't think I'll have time to do it over the next few months - so, for now I'll be content with what I have..... it ain't so bad. <img src="/forums/images/graemlins/wink.gif" alt="" />

Frank