103 home build
 

Well I have had my 103 running for about 1000 miles. I had this dyno run at 500 just to see where I was at. I had a exhaust manifold leak on the rear cylinder since corrected. I think that is why it leaned
out so much at 2500. It was giving my O2 sensors fits. I have been working on my baffles to try to add some back pressure. I can tell there is a difference at the upper rpms. This is a true dual setup with S&S oval mufflers. The build is SE 103 (Jim's) crank, SE forged flat top pistons, home ported heads stock valve sizes, 85 cc chambers, woods beehive springs, black diamond valves, TP rocker boxes and roller rockers, cometic .040 head gasket, Woods tw6gh cams, SE 50mm throttle body, delkron cam plate, fueling oil pump. DTT wego II computer.

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RE: 103 home build
 

with all that work the numbers are a little dissapointing

RE: 103 home build
 

I would agree the numbers are lower than I was hoping for. I had several things I was trying to achieve which are contradictory to big numbers. Keeping the exhaust noise lower than other setups I have had. Having a flat torque curve was important also this is on my ultra and I sometimes pull a trailer. That said I know there is more power in there and I still working out the bugs. I have not seen a 2 into 1 exhaust that is quiet enough for my liking the D&D fatcat comes to mind. I haven't seen many users with the Twin Tech closed loop injection with high numbers either. I have a dual 50 mm throttle body that I am thinking of trying.

RE: 103 home build
 

I think compression could have been set alittle higher, and the headwork may be holding things back abit too.

I would expect around 115 to 125 lbs of torque and 105 to 110 HP. with a 103 build similar to this.

RE: 103 home build
 

The compression ratio is 10.08 to 1 corrected compression is 9.29 for the cam. The cylinder head flow numbers

Readings at 28" WC Temp 72 Baro 30.18 humidity 84% 85 cc chambers

Lift --------- Intake ---------- Exhaust
100 ---------- 71.5 ----------- 60.0
200 -------- 145.0 ---------- 122.2
300 -------- 207.1 ---------- 169.7
400 -------- 234.3 ---------- 190.6
500 -------- 251.0 ---------- 200.8
600 -------- 258.1 ---------- 207.4

RE: 103 home build
 

i think you need a tune...

RE: 103 home build
 

The DTT TCFI II is an excellent tool in the right hands. My 103 last year made 120hp, 122 tq max and when tuned for economy where I eventually left it was making 112 hp and 118tq self tuned with the DTT. You need to work some more with this, but the mix and match build you did might not get much more than where it is.

Do not try the dual runner throttle body as it is overkill for your build and will just give you tuning fits. I am running a SE 50mm with SE 4.89gm/sec injectors on my 120 and it pulls fine. Ran the same TB and injectors on my 103 and it was more than enough.

Go back to tuning, that is where any gains will be made.

RE: 103 home build
 

I think I have found some more power in the twin tech. I got a copy of the mega squirt viewer which will display 12 lines of info from the log file at once. I noticed on a wide open throttle run the afr ratio was staying at 13.5 when the map said it should be 12.5 . I suspect that since my estimated hp was dialed in at 100 the max pulse width held the computer back. Since then I have been working the estimated hp up 10 at a time and doing a wot run and checking the graphs. I now have it set at 145 hp and and the pulse width of 16 the afr is staying where the map tells it to be. I just got back from a 200 mile run over a 5500 ft mountain pass twice and got 42 mpg. I still am working on fine tuning the advance curve to get rid of the pinging almost gone now. The heat wave we just had from the 50s to the high 90s in two days brought that out. I haven't had a chance to get back on the dyno (the busy season) to see if I have been making progress. My seat of the pants dyno says yes and rideability has been improving. I have been working on baffling my mufflers and now the only aggravation is the noise out of the intake. I hadn't noticed it until short helmet season. I lined the inside of the air cleaner cover with 1/8 foam to absorb some of the reflected noise with some improvement. Would you be interested in posting a copy of your tuning file so I could compare what you have done?

RE: 103 home build
 

I have a feeling theres a lot of torque just waiting to tear up your rear tire!

RE: 103 home build
 

I see you have a fat cat 2>1 system. I have seen remarks like fat cat with quiet baffle. I have been to their website and can find nothing to indicate quiet baffles? What is your experience with your mufflers?