We just built a 95", not 98" like we usully build, for a client in Clay NY.
S&S .570 at 193 ccp, our Stage II Heads, V&H Big Radius, 98 hp 107 ft/lbs, as an example.
Might be on our Facebook already?
A Wood TW-8G (gear drive application) would lay substancially more into that, and our Stage III Super-Tour Head would be used to let-r-rip, into the mid-teens on hp.
Scott

 

 

Ran on the dyno for numbers shortly after the build was completed and broken in. We played with carb jetting while on the dyno but no DTT tuning. Heres the dyno, poor quality but its what I got. I've tweaked timing and leaned carb on the main jet after this printout. It feels like it performs stronger now but no current dyno runs




Lots of talk about the exhaust. I dont see how an exhaust is going to alter things in any significant way. I obviously know exhausts are an important part of a motor build, this pipe im running is a 2 into 1 from a reputable exhaust manufacturer. It isnt some pipe i mig welded out of scrap in the garage.
https://cobrausa-vtwin.com/softailsr...2_into_1/6420/


Thanks for the discussion here guys, appreciate it.

 

Agree with the other comments regarding the dyno numbers; numbers are low, particularly HP which is down about 10 points from what is typical of similar builds. I would also expect TQ to be up another 3-5 points. I have built a few mild 95" motors and, in my limited experience 95" motors with "street" ported heads, compression with CCP in the 185-190psi range, similar cam profiles, good exhaust and tune is that they will hit 95HP/105TQ, give or take a couple of points every time; nothing magic. Those are EFI numbers; carbureted motors will usually show a bit less since they cannot be dialed in as tightly as and EFI motor. Also suprised that the OP is not experiencing detonation with that much compression on the 37 cam. I don't know enough about the Cobra pipe to say that the pipe is the problem but do know that it is not a popular choice.

EDIT #1: The OP posted the dyno chart while I was typing. As I said, don't know enough about the pipe to call it out as the source of the problem but I would think the heads are holding the numbers back. I have built that same configuration with '06 heads, not ported, 37 cams, 185 CCP with Rinehart Crossbacks and that motor made 96TQ/104HP; EFI numers but I would expect a carbureted bike to get close to that with some AFR and timing tweaking on a dyno. Don't know who ported the heads but that's where I would be looking for improvement. JMHO.

EDIT#2: I doubt sumping is the issue with the 102TQ; agreed the number should be a few points higher but it is in the ball park but there are several other factors that could easily be holding that number back a bit. If the OP gets the HP number up, TQ will follow. Still think heads are the bottleneck.

 

 

Havent checked for sumping, never really thought about it though. From what I can gather sumping isnt a problem but shouldnt rule it out. Never pulled that case plug either to really check into it.

Heads were ported by bean @ big boyz in maine.
At the time of those dyno runs I had the DTT settings significantly retarded, started there as a base line and never messed with it on the dyno. Since then I've advanced timing and changed the overall spark curve. That made a serious improvement in seat of the pants.

So the general consensus here is to leave the 37 cam in and go after an exhaust change and tuning looking at the AF graph on the dyno again?

 

 

Sure dont know that. Its whatever stock baffle was installed in the pipe at the factory.

 

you are definitely having a flow issue,,,I don't have any personal experience with your Cobra pipe, and I use Cobra stuff on Jap bikes all the time and it is usually a great product. All that being said, your particular pipe, since not a lot of people have reported experience with it, would be the first thing to look for. Maybe your dyno shop has a "test" pipe you could install and re-test the bike to confirm. The other thing is, by your signature line, it looks like you have the stock sized CV carb on the bike. A mikuni 42 or S&S E carb would also offer up better results as the basic hole is larger.
If you brought the bike to me, i'd want to try a different pipe first (i do keep test systems at my place), see what the results were, then make decisions at that point. Maybe you could find someone to help you out with a loaner?
The main point is the the exhaust system you choose to run has HUGE impacts on the preformance, there just is no question about it, confirmed fact. The only way to know for sure if that is what is holding you back and by how much would be to swap it and re-test. if there is a large difference, you know what to do. If not, then you can decide which other direction you need to go in, or if you can live with it.
marco

 

2 things will pinch the hp like that.
1) plugged up exhaust.
2) cylinder head
Almost 99.99% guarantee it is not sumping.
Scott