Way larger than his? What? He has a 248/254 in there and out of those examples non were even close to that size cam, the biggest one was a 242/248.

How am I an a hole for trying to prove something wrong with facts and no name calling or anything like that?

 

All of that should of been in your first post then.

Now on to your issue. I think 23* is very low and is a reason for a good bit of the power loss. Your cylinder heads will dictate your final timing. Most stock casting heads will be around the 28* mark some aftermarket heads, depending on the chamber, will have a lil less. Your 9 inch rear isn't helping any either. That is one of the most power robbing rears out there. No matter though, you need it to take the abuse and get the power to the ground. Unlocked is another issue but usually Vigs are pretty efficient even unlocked. Just a side note, you will need more converter for that motor with those cubes and cam.

I would like to know what exhaust is on the car. Ideally, I would like to see a 1 7/8-2 inch primary with a 3 inch collector and a true dual setup for max power.

IMO, I have never been a fan of the Dart LS heads and Larry Meaux is local to me but in the LS world, I have not been impressed with some of the local cars I have seen with his heads on.

Where did you get it tuned at? Do you have a dyno sheet? Did you run it down the 1/4 yet?

 

1 7/8 texas speed headers 3 inch collectors into a merge single four inch to the back to a dual splinter muffler with 2 2 and a half coming out back

 

What kind of muffler is that? You mean Spintech? If its a cross flow muffler then that is a restriction. What does your intake consist of before the throttle body?

You have alot of factors hindering you and we just need to nail them down one by one.

As for your camshaft, you spent alot of money on your heads and having them ported and then money spent on stroking a bottom half, why would skimp and use off the shelf cam? At that point, it would of been wise to get a cam spec'd out by one of the sponsors on here and its not much more money. Some of them are Martin@Tick, Geoff Skinner@EPS, and Pat G. It costs an extra 25 bucks for them to get you one custom to work with your setup. Not saying the TSP giant is a bad cam but it has been around for awhile and there are alot of newer lobes and cam technology out now.

 

I meant spintech

 

Ftp lid with a k/n

 

Well, I don't see anything wrong with the FTP lid but I would take that cross flow spintech off and see what it would do.

I dyno'd a 3rd gen with a 355 with the same spintech piping you have but it had a 4 inch in and a 4 inch out muffler. I took the muffler off and I thing it gained 2 hp. That could of been anything though.

You on the other hand have a bigger motor flowing way more air. You would need the same muffler or run it straight off the y pipe. There was a thread on here a long time ago and a bunch of guys put up their specs and what cat back they were running and if they had a cutout. The consensus was that the magnaflow catback was the least restrictive but nothing beat a cutout.

 

Than the person I was specifically talking about. That is what you were trying to prove me wrong on.

But also silver, I wouldn't say aftermarket heads will not also be able to use 28* to their advantage. That is an assumption that doesn't always hold true. I have seen some aftermarket heads take 30* and make very good power. Would I run that on the street? Probably not, but still, it happens.

 

Then that head is inefficient or something is wrong with the build. Most aftermarket heads get away with 27 somtimes 26 when more compression is being used. For example MOZEZ heads which we all know are bad *** heads and efficient to boot can run even less timing. That is why SBC end up around 36*. The cylinder head is less efficient.

 

The OP couldn't post his dyno graph so this is what he sent to me so I could pot it.

 

That whole thing looks wrong. Usually you try mirror run fornrun so you have some idea of what is going on.

Ps tyler has tuning notes!

 

You caught that too!!!

The graph is in mph. I wish it would of been in rpm. Going by other graphs, those start at 2500 rpm and increases at 500 rpm per vertical line. If that is the case then this motor peaked at roughly 5500 rpm and that is all wrong for a 408 with a 248/254 cam.

With 23* of timing and the AFR at 12.6 alot of work needs to be done.

 

The entire combo seems wrong to me though.

Even the original graph is odd. Almost plateaus then takes off. The red numbers cross at different intervals. Either it has an odd converter or it was in the wrong gear?

Too many questions. Although that huge dip LOOKS like knock it doesnt show on the AFR so idk how to explain that one. A stalled auto during a shift would show a large torque spike and a change in mph a bit.

Silver that is likely why they have the graph in mph. A 3600 stall in rpm...the graph would last 2 seconds lol.

 

It could also be that they started the pull too early and the converter flashed at that point too. We could go on for days about this graph, the OP needs to look over his combo and check thru the whole engine to make sure every thing is kosher.

This car should be making about another 40 horses easy with this setup.

OP, I would check compression to make sure everything is good on that part and that will tell you also if the cam might be off. You're missing roughly about 5* of timing which is good for some power right there. Take that muffler off and see if the car puts down a better number too. Check to see if you throttle blade is opening up all the way with the pedal pressed to the floor. I have seen that before with the cable adjusted wrong. Check your plugs and make sure they are good. You could possibly have a weak coil. Check that converter and make sure its coupling right and putting your power to the ground. I have seen converters that were back yard pieces of junk that couldn't hold the power of a lawnmower, let alone a 408.

I think that list should keep you busy for awhile. Check back with us and let us know what you find.

 

Just trying to tell the guy what's a realistic goal to shoot for, especially given his setup. I said that through all that drivetrain and rear end even a 408 shouldn't expect to be making huge numbers. Because in reality, 408s don't make that much more power than 364s, so looking for high 400s in a 408 with that drivetrain is kinda out of the realistic norm.

 

Sorry that graph was with a yank 4000 now I have a 3600 vig nitrous converter but haven't sprayed it yet until I get the motor right

 

Your ideas do not seem realistic as to advantages of a 408 vs a 364. He should be at 460 or a tad over with the correct combo and quite a bit more tq. Nearly all the dynos you quoted had afr heads and mostly.....custom cams....hmm....on one part your links seem right. And most of those were done by patg.

And as long as it is a new vig and locked to remove some fluid coupling loss, it should be good.

 

My timing is @ 27 degrees on 91 octane gas / no ethanol.

 

I made 505/490 thrue stock ls6 heads with 23*timing on my 416.. I tried 27* and gained 1hp, and I'm on E85