Oops !! Big Boyz Street Heads with SE-203's

[springer-]

Don't be afraid of the 203's you got from the dealer, in the right application, they work great.

I found this on another forum, I thought I would repost it here....

Here is a link to the tuners website http://www.simonsperformance.com/

Since I haven't seen too many posts with 95" builds using Big Boyz Cycles services, I'll post mine:

'05 FLHTCI efi
95" Stage 2 (203 cams)
Big Boyz Street porting with the heads cc'd for 9.6/1 CR
Cometic .030
V&H Propipe HS
SERT
HD adjustable pushrods, forged rocker supports and high strength studs

Just got back from dyno. Tuned by Andy Simon, Simon's Performance in Penndel, PA. 95.3 HP 108.7 TQ SAE.
When I get access to a scanner, I'll post the dyno sheet. I think the numbers are decent for the build. Anyone think otherwise?
Tim

It was a 4th gear pull, Bob, although Andy did make a 5th gear run which came up only two tenths off the 4th gear run HP-wise. Looking forward to some warm(er) weather to try it out! Thanks to all for the kind words.

Tim

[HogJR]

"It was a 4th gear pull, Bob, although Andy did make a 5th gear run which came up only two tenths off the 4th gear run HP-wise. Looking forward to some warm(er) weather to try it out! Thanks to all for the kind words."

I thought my build was about as basic as it got! Just goes to show..........
I do have questions though about the graph:

If I did a 5th gear pull would my numbers respond the same, with no real increase? Is that possible?

Why does it start around 2500 rpm?

While the final numbers are admittedly good, I hit 90 TQ about 700rpms sooner and stay above it until 300 rpms later. Is that because of the 37G?

[Totenkopf]

That is by FAR the best 203 sheet I've ever seen and it makes me wonder how can it be. Normally, they are nowhere close to this, even with good heads and pipes.

Notice the HP and where it stops climbing and when it noses over.

HogJr, yes it's the 37 allowing yours a broader curve and iirc, your HP quits at 5800.

Although, I haven't gotten my latest sheet yet from the dealer, I am told that with my 2* retard on the 37 in my motor that my HP curve stops climbing at 6200 and the torque curve is shifted over just a little bit, peaking at 3700.

[springer-]

Originally Posted by Totenkopf

That is by FAR the best 203 sheet I've ever seen and it makes me wonder how can it be. Normally, they are nowhere close to this, even with good heads and pipes.

Notice the HP and where it stops climbing and when it noses over.

HogJr, yes it's the 37 allowing yours a broader curve and iirc, your HP quits at 5800.

Although, I haven't gotten my latest sheet yet from the dealer, I am told that with my 2* retard on the 37 in my motor that my HP curve stops climbing at 6200 and the torque curve is shifted over just a little bit, peaking at 3700.

Actually there are a couple comparible 203 builds out there.

Check out http://www.nightrider.com/biketech/hplist_twin_cam.htm

And http://www.latus-harley-davidson.com...d=94&posts=114

In an unrelated matter, did you know that if you run a spell check on your username (Totenkopf), it comes up with "Stinkpot" as the correct spelling?? Whats up with that?? LOL

[Totenkopf]

Originally Posted by springer-

Actually there are a couple comparible 203 builds out there.

Check out http://www.nightrider.com/biketech/hplist_twin_cam.htm

And http://www.latus-harley-davidson.com...d=94&posts=114

In an unrelated matter, did you know that if you run a spell check on your username (Totenkopf), it comes up with "Stinkpot" as the correct spelling?? Whats up with that?? LOL

I'll be damned! still, they appear to be exceptional and you can see the bevy of lesser 203 dyno sheet builds that are more in line with what I used to seeing. The difference I see is the top end nosing over early compared to other cams but hey! if that ain't important to 'ya, then the 203 just came up a notch in my book.

Stinkpot..... bwahahahaha....!!!! they found me out.

[YankeeBob]

Originally Posted by springer-

In an unrelated matter, did you know that if you run a spell check on your username (Totenkopf), it comes up with "Stinkpot" as the correct spelling?? Whats up with that?? LOL

[nw_guy4_fun]

So rather than taking a few dyno runs out of context how about looking at a rolling average for a more reliable information source?
I have seen a few over 100 with 203s 1 of which on Latus site. Using this as the norm would be very disappointing for many because this is in the lower under 5 percentile of typical builds.

[springer-]

The typical builds I see with 203's are stock heads. On nightriders site alone, 10 out of 12 builds listing 203's have 98lbs of torque or more and 8 of them are over 100lbs. Most of them have other than stock heads. I don't think they are taken out of context, if they were stock heads I would agree that the numbers are too high.

[Seahag]

I have a friend that also has a SE 203 cam putting out 92hp and 104 lb-ft.

[2001FLHT]

Seahag,
What else does your friend have in their build? I wonder if you can recommend the tuner you both used. I see that you are from Minnesota.
Thanks.

[Seahag]

Originally Posted by 2001FLHT

Seahag,
What else does your friend have in their build? I wonder if you can recommend the tuner you both used. I see that you are from Minnesota.
Thanks.

We both had our bikes dyno-tuned at Faribault HD by Jason. He does a really nice job with fuel injected bikes. I think he could have done a better job on mine as far as dialing in the timing more....but I think I've got that worked out now myself. I just need to get it back on a dyno to check my results. I live in Mankato; and our local dealer just got in their own dyno over the winter; so I can get it checked locally now.

My friend is running an unconventional set up, that you won't want to duplicate. The dealer (Blaine HD) convinced him to go with the big bore "kit" then upgrade the heads and pistons to HTCC...for 10.5 compression. The problem is, they wouldn't let him substitute another cam for the SE 203, that comes with the "kit"; so he's running too much compression for that cam. It took a lot of tuning to get it to stop pinging. He is looking for another cam now.

[2001FLHT]

I got a 42MM Mikuni and had it dyno'd at St. Croix HD. Mikel that works is service at Fairbault HD used to work up in St. Paul and I have heard good things about Jason as well. I think I am going with some BigBoyz heads when I can get the money and time.
Thanks

[Seahag]

If you have the big bore kit with those 203's and headwork, I think you will be satisfied...unless you've become a power junkie. I never worried much about winning dyno shootouts...I just wanted my bagger to move out like my old Suzuki 750 inline four used to. I started with a stage one like everybody, and it still felt slow...it progressed from there to the point it is now. I have plenty of power now and I think I've got a nice reliable build. Time to ride it now till it breaks.

[2001FLHT]

I'm really trying to keep this thing blue collar and not grabbing any attention. I've got to ride it for quite a while. Just wondering if I am getting all I can out of what I've done.
Thanks

[Seahag]

Originally Posted by 2001FLHT

I'm really trying to keep this thing blue collar and not grabbing any attention. I've got to ride it for quite a while. Just wondering if I am getting all I can out of what I've done.
Thanks

Not without some headwork you're not. From the earliest versions of the production twin cam, respected techs have been saying the heads are more restrictive than the EVO models, even though they are feeding a larger engine. The design of the chamber itself is supposed to be superior though....its the portwork that is lacking.

Donny Peterson, who writes for American Iron magazine, was supposedly privy to the details of the twin cam when they were still in the prototype phase. He said none of the prototype heads were so restrictive, and he believes the MoCo purposefully re-engineered them to be more restrictive in order to create more of a market for their aftermarket line of SE heads.