308 V12 conversion begins

I also for got to put a stock TR on the graph for comparison.

You can see this model says I'll be losing a little torgue below 3550-4000 rpm. I question the results a little in that it says a muffler hurts the low end and I've never seen that on a real dyno graph, often just the opposit. It will be intersting to load the same files into the new software and see what differences there are in the results. In real life I'm pretty sure I'll be able to at least match the stock low end power....the engine is 10% bigger after all
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I think that is exactly the concern and another reason why the blower graph was just for fun.....I don't want an exploding gear box. I'm aiming and designing for 800 as a good way too hard anyway number. If it goes over a little fine, if goes under a little.....I'm just going to lie to all of you

 

I heard Bob was running the engines to 30 psi and getting 1200 from a tr and 800 from a 308. Here's the stock tr simulation with a couple pretty small turbos and intercooler added.
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I think we're pretty much agreeing on everything here.

I will not have adjustable cam timing of any kind..it's too much trouble to figureout how to install it......maybe in the next build.

The fuel will be full sequentail with 24 staged injectors (12 low power, 12 more coming on at high power).

There will be 12 ITBs and some sort of air box above them.

What I'm not settled on is spark. I will have at least 2 coils and from what I've read for a 12 at 9000 rpm that will handle the job nicely. I like this answer becasue it just looks more right on an 80s engine to me. If I use 2 haltech or motec ecus will run 2 6 cyl or 4 3 cyl distributors. The motec can take the next step and go waste spark or direct fire....but I really am unclear on what that adds besides more parts. My understanding is the OEM move to COP was diven mainly by needing to meet a no emissions effecting maintanance for 100k miles requirement, but maybe there's more to it?

 

You do hit some important stuff here let me clearify a little what I'm thinking.

Whenever I say distributor I mean a rotor and cap with no other stuff in it. All the spark timing would be handled by the ecu and the option to tweak the timing cylinder by cylinder is exactly the same as it would be with COP ignition. There is a little power loss in the wires and rotor, but I think the larger coil that can be used easily makes up for that. I think it just comes down to maintenance and the bother of running the spark plug wires, but I prefer the wires for the right look.

I’m doing the best I can to match everything cylinder to cylinder. When I flow the heads they will be done with the manifold and header installed and I’ll be shooting for ½% error. The error in compression cylinder to cylinder should come out very close as well with the machine work that done on the block and my CCing the heads. I really don't think I’ll need to worry about cylinder to cylinder tuning…but having the option takes a lot of worry out.

The ITBs. The stock manifolds are tuned runner which replaced the multi-carbs. I think I can make the ITB setup look like something in between and nothing that catches your eye. My thought right now is to take a stock 308 QV plenum and stretch it so I can use it as the air box on top of the ITBs. In my mind that will make it look very much like a stock QV intake system, at least at first glance. Then I do the same satin polish on the TR cam covers that the QV covers have and I have a 12 cylinder version of the stock engine. That’s the working plan anyway.

 

Thanks. Hopefully next year when you're on holiday I'll have the conclusion ready

That's what I thought 103 pages ago

 

Just wait til I post a couple timing graphs for the cams I'm planning.......2 big smooth, perfectly matched profiles

I finished reading through the software manual tonight and I feel like my head is going to explode. There is clearly a reason they call this the pro version. It should be here tomorrow so I can see what there is to see.

Apparently it is rare for the wave analysis part to find more hp than the simple fill and empty analysis the cheaper package does because the algorithms in the simple analysis assume optimal tuning. What the fancy, expensive, and hard to use part does is help you figure out what optimal tuning is exactly……but it won’t do any iteration stuff with the fancy wave calculation because that just plain takes too long to run. So it looks like the you do an optimization in the simple analysis mode then spend your time hunting for the intake and exhaust dimensions that get you that answer. They do give some basic formulas to get a starting point, so hopefully it will go fairly quickly.

 

The new software got here. I did a quick model of thew engine I assembled int he other software and run the simple analysis and got about the same answer. Then I ran the wave model and got a little over 1/2 the power.....clearly it doesn't like something I was planning. I've got some work to do.....
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Well.....I need to sent an email to the software people I think. The ITB setting seems buggered on a 12 cylinder. I tuned the engine as a 3 or 6 cyl and it's fine, but at 12 there is no setting for total air flow that supplies engouhg air. On the 3 cyl I can use 1200 cfm and see very little change if I up it to 1500, but 7000 (the software max) is no where near enough for a 12 cylinder. Stange.

Away, after some playing I still don't have quite the power I saw with the old software, but I'm close. I got the torque curve is much flatter and am using a lower flowing head and it seems like the intake port is still a little too big.

The iteration function seems to just bugger up the engine....I'll play with it a little more but so far I've been kicking its butt at making nice looking curves.
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A little smaller port, a little less cam, a touch more flow.....better yet.
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Thanks.

I'm not sure on how close the softeware will be, I think it will be pretty close. The numbers seem right and match basic per cylinder per CC numbers for engines I have seem dyno results for....I think it's good. The question will be how close the software gets the tuning vs the peak number. This engine is pretty sensative to the header design and intake track length to keep the curves anything like smooth and flat. We'll see.

 

Steve,
Thanks for chiming in!

I'm in a little bit of a catch 22 in that none of the parts that matter actually exist.

I stopped working on the port design thinking I didn't want to do any more until I had the intake and headers so I could flow them together.

I can't design the intake or headers without knowing the cam specs and intake flow.

I can't design the cam without knowing the design of the intake, headers and port flow.

And there we are, running in a circle. I'm going to have to pick something to start with. My plan is that the cam is were I personally have the least control so I'm thinking I'm going to pick a cam and design around it. The cam guy has about 3000 masters and I'm going to have to be happy with 1 (of them unless I want to pay him to make a new one or make it for him) and design everything to match it.

My plan with the cam is to stay with a profile that doesn't beat the snot out of the valve train. What I've been playing with are designs that dynomation calls about 3.3 to 3.4 on it's aggressive scale. In DynoSim SC the cam was 270 seat to seat and 245 at .050 with .450 lift for the intake and .400 lift for the exhaust (I'm setting up for 35mm buckets in the intake and stock 33m in the exhaust). That gave a 3.3ish number to it so more than stock, but certainly not a race cam.

This new software gave the same cam a 4.3 so I went to 280 seat to seat with the 245 at .050 to get back to 3.3ish. This is the cam I played with most of the night. At the end of the night I went down to 270 seat to seat and 235 at .050 with the same lifts to try and help the bottom end out a bit which it clearly did but I had to add 5 cfm to the head flow to keep the hp up (I think I'll pick up at least 5 once I finish up the seats, so I think I was still using good numbers).

It's funny you mention 110 LSA, that is exactly what I've been using. DynoSim SC liked this and only this timing for this engine. The new dynomation seems to like a little less for top end and a little more for bottom end which makes sense but I didn't play with it much before I put it back to 110 and left it alone because it still seemed to give the best over all results.



Once I lock the cam down a bit I'll make at least 1 port worth of intake manifold and 1 header pipe to get back on the flow bench. Right now the intake flow with 1" or 10" stack is almost exactly what is in the "stock 4 valve head" sheet loaded in the software so that is the flow profile I've been using the last couple days with 32mm intakes and 27mm exhausts. I did change the flow data to reflect these valves as the test valve as these are smaller than what was in there. I'm going to choose the throttle body size on the flow bench to be large enough to not cause any very significant restriction.

So that is were I am with the cam at the moment. Any help you can give on profile data or ideas would be a great help. My email is [email protected]

 

I sent the software guys and email about the 3 cyl and 12 cyl versions not matching in any way and Larry from motion software just got an answer to me in under an hour confirming that it sure looks like a bug. He said he'd dig into it and try and get back to later today if possible. He's clearly serious about selling a good product.

I don't know what it is with me, this project, and software. First a massive bug in ProE that nearly ruined my cams now the simulation software can't calculate my engine. Crazy.....I can't wait to see what comes next.