His motor is being choked... the question is by what? Whenever you see the torque curve higher the hp curve, then something is choking it.

The cam should be fine, but should be peaking at 6200-6300rpm... not at 5800rpm. Thats a sign of some choking going on.

The heads should be fine.

Compression should be fine and still make atleast 380-390rwhp.

Honestly, I'd take it to another dyno to for a few pulls. Its cheaper than starting to swap out parts.

 

I agree, don't freak out and start swapping parts and spending more money. I think your H/C is good, the heads flow around 270-280 which is decent, not enough for a stroker but will support over 400 rwhp. The cam has been proven to make more than 400 too so I doubt those are your issues. I would go back and check valve lash, no exhaust leaks, etc. and go somewhere else to dyno.

For max performance what everyone is saying is correct, but for a good solid street machine you don't need to go crazy, just tweak the little things.

Edit: I just noticed you are running Comp R lifters. Search this board and you should find some good tips on adjusting lash with those.

 

Not enough head, not enough cam, not enough compression, and restrictive mufflers. You'll probably pick up about 15-20 rwhp by going through a non-chambered exhaust setup on a 396. I picked up around 20rwhp with my 396 going from a 4" Flowmaster to a 4" Dynomax Ultraflow Bullet. You might want to retard the cam a couple degrees if you aren't going to change it completely.

Mike

 

Like others have mentioned ....The 195cc AFR heads "especially" with just their "street porting"....are WAY small for a 396 (both runner size, "and" flow wise) reguardless of what they rate them for.......195-205cc intake runner volumes are the norm on good running Heads & Cam stock short blocks(and 355's)......The additional stroke of a 396 and it's MUCH increased piston speed(IE: harder to breathe as the RPM increases) NEEDS (IE:requires) a better set of heads to make real good power, or power is easily choked off...........this is a big part of the reason you see all these engine combos out there that people do ranging from stock shortblocks, to 383's and 396's and many times the power outputs are nearly the same(or even worse on the larger displacement motors)......this is mostly because people aren't using the right heads for their combo.......ofcourse the cam being used here is a bit on the small side for a 396(but it will still make alright power)....and compression can always be higher........but the big problem is the heads..........a set of Larger AFR or TFS heads with runners in the 210-230ish cc intake runner range.....with flow well eclipsing the 300 mark at .500 .550 lift will turn that whole combo around like night and day.......and the great thing about the 396 is that you'll loose nearly zero low end drivability..............Joe

 

Couple of thoughts. One is like stated above you should have went higher on the compression. 2nd is if the port match of the intake to the heads is off that will kill power in a heart beat.

 

Thanks to all for the good advice. I definatly need to take a look at the exhaust, intake ports,heads and cam. the chambered muffler has to go....i'm looking at a hooker cat back with a cutout....and then see what gains i mangage to get there. Aslo the car won't be annoyingly loud....

 

As others have stated, the as-cast 195s aren't enough head and you could go with a different cam and pick up some decent power - but you should still be in the 400 rwhp range with that setup.

I'd start with getting a cutout or two. That alone will probably pick you up 15 - 20 rwhp. The A/F ratio looks fine, but that doesn't tell everything about the tune. Who tuned the car? Your compression is fairly low as well. I run 11.5:1 and run 91 w/out any problems.

Get a cutout and a good tuner to tune the car and you should be right around 400 rwhp. If you're hoping for much more than that, you need to get those heads/intake ported and get a different cam as you have a mess of unmatched parts.

 

Who picked these parts? Cam, compression, heads, exhaust, manifold work, ect?

 

The 195s aren't 'stroker rated'. AFRs have been shown to flow 10-15% less than AFR claims. As others have stated, ported stock castings would have been a better choice than unported AFR 195s.

 

The "as cast' heads from AFR really should say...."Needs to be ported". Whoever said they flowed in the 270-280 range needs to come up with a flow sheet for "as cast" 195 heads. I have a flow sheet from an "as cast" 210 AFR's that flows a whopping 232 cfm before porting. My Trick Flows with upgraded 2.05 valves only flowed 262. yes, I was not jumping for joy when I got them.

Somehow people think just buying a set of aftermarket heads is the way to go. It ain't..........Unless your prepared to spend a bunch of bucks in addition to a bunch of bucks to make them work right.

Really, if it was me I'd take it back to the dyno and try removing the intake and exhaust to see what it does. Then work on the rest but the unported 195 heads with 70cc chambers is a red flag for sure.

 

So far this is what is wrong based off the this thread:

Your heads
Your cam
Your exhaust
Your intake
Your compression

Lets address this "wrong" stuff....

The AFR 195 street head is plenty of head for this motor and the rpm range it is operating in. Those heads I bet flow in the 260-270 @ .600 and 190-200 @ .600 lift....which there is nothing wrong with...especially on the exhaust side. I made 358/450 @ the wheels with ****ty stock castings on my old 388"...your AFR 195's are substantially better.

The cam is not the culprit....a little mild for my taste, but none the less, it is a good cam which should be even better in a stroker application.

The exhaust is plenty of exhaust for this setup.

The intake is fine...very rarely does actually opening the runners show a difference on a dyno.

The compression...how big is the dome on your piston? What are your specs...how far in the hole? How thick are your head gaskets?

So let's address the basics.

Is your throttle body opening all the way?
Vaccum leaks?
Exhaust leaks?
How much timing?
Stupid question, what gear did you dyno?
When was the last time you went over the valves?
What spark plug gap?

 

I have seen a number of threads over the years showing the smaller AFRs in the 230-240ish range, and keep in mind that peak flow #s don't mean a whole lot. How many guys have gone very fast with out-of-the-box 195s? Just curious, cause I haven't seen many.

I agree that the cam isn't the main culprit - a cc306 will make more than 400 rwhp with the right setup - but he could do much better and keep the car very driveable while making more power everywhere in the power curve. My custom cam is quite a bit more aggressive than a 306 and extremely driveable - 6th gear at 50 mph with 3.23s behind a 6 speed w/out any problem.

I wouldn't call the exhaust fine when he's probably leaving 15 rwhp on the table compared to a cutout, let alone a true dual setup.

I don't know of any dyno comparisons showing before/after a ported intake, but a lot of the quicker cars are running ported LT1/4 intake manifolds.

Compression is definitely low for his setup, but again not the main culpret.
Agreed that all of this stuff should be checked, but I think most people in this thread ASSume that someone who's doing a 396 buildup would have checked these things before starting a new thread about low dyno numbers. If not, definitely check all the little stuff that can throw your performance off.

I don't think most people in this thread think that this guy's setup can't make 'decent' power (390-400 rwhp), but it's still a mismatched setup and won't make the 430-460 rwhp most would expect with a 396 with aftermarket castings.

 

He should be glad he has a 6 speed and stock rear....throw in a loose non-locking converter, a th-400, a 12 bolt, slicks and then dyno it.

 

I'm going buy what is stated in the owners manual and my discussions with afr before I purchased my own heads not an advertisement. There are several AFR versions if he has the street competition port than he shouldn't be so restricted by the heads. It is true that you can clean up the AFR heads, but for the most part any Cnc'd head can use some touch up work, but AFR is known for being the closest to advertised. I bet my bottom dollar if this guy port matched his intake and swaped into a custom cam, he would be making some KUDOS!

 

I have a personal friend that had his LT1 intake opened up...he did and it gained NILCH on his 355.