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I have an 06 efi softail and I am half done installing tw37 cams. The bike is an 88" with se AC, thunderheader, and I am doing a TMAT right now also. I realize this is prob not the best cam for a low compression 88 but very soon I will be pulling the top end. I am thinking about having Big Boyz do a street port and SE flat top pistons and setting it up at about 9.8:1. So I am sure some of you have similiar combos, approx what can I expect for power? Thanks!
 

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I think that BvBob did a similar build last year and got in the neighborhood of 93 lb/ft if I recall and something like 80 hp. But, just off the top of my head, I would say that 90-95 lb/ft and 80-85 hp would be in the ballpark.
 

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Do you mean around 80hp and 90 tq just bolting the cams in? I am hoping that if the heads are done and bb kit is installed that I can make more than that!
 

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Do you mean around 80hp and 90 tq just bolting the cams in? I am hoping that if the heads are done and bb kit is installed that I can make more than that!
I have bolted in 37's on a couple 88's they go low 80's hp 88- 90 tq
that pipe will help.
95ci with beans heads. 90-95 hp 100-105 tq
 

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Yup that's what I mean. The heads, unless you go really radical, aren't going to get you a bunch more torque but will cause the torque curve to flatten out on the right which yields a higher peak HP number. 90-95 lb/ft and 85 hp or so out of an 88" with cams is actually quite respectable I think. And fun to ride I might add.
 

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Yup that's what I mean. The heads, unless you go really radical, aren't going to get you a bunch more torque but will cause the torque curve to flatten out on the right which yields a higher peak HP number. 90-95 lb/ft and 85 hp or so out of an 88" with cams is actually quite respectable I think. And fun to ride I might add.
Ok that makes more sense to me!
 

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I have done quite a few of the BigBoyz head combo's with various cams and the 37 is my favorite for a 95 inch flat top build, mid 90's hp and 105 or so torque. The pipes will dictate where that torque comes in and how long it holds on for.
 

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I have done quite a few of the BigBoyz head combo's with various cams and the 37 is my favorite for a 95 inch flat top build, mid 90's hp and 105 or so torque. The pipes will dictate where that torque comes in and how long it holds on for.
Ok that sounds great, did you find setting it up at 9.8:1 works the best? I think my thunderheader should help squeeze the most power out of the package. Should I be boring or reworking the TB? I was also considering using some 98" forged pistons but I would like to keep to a low budget.
 

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tyrell: if you stay mild with the build, e.g. some mild head porting, a set of bolt in cams, and leave it at 88" you don't need to do anything to the TB and you will have the most bang for buck and, I think, be very satisfied. If you are talking going to 98" however, well that is another subject and I would recommend a different cam set and extensive head work, as well as crank work. This would be a lot more $$$$ but a well built 98" will do over 100 hp and in the neighborhood of 110 lb/ft from what I've seen. If anything have your cylinders rebored to 95", stay with the big bore flat top pistons, and use the same 37 cams. Have the same mild headwork done. That will yield 105ish lb/ft and 95-100 hp. You're looking at roughly $300 dollars more or so in parts than what you have planned for your 88".
 

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03 88ci
37g cams w/gear drive
S&S Power tune duals
S&S SPO mufflers
SE stage1 air filter
Dyno tuned
tuner said the dip is because of the low compression.
 

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tyrell: notice the pipes in the above combo. With a good 2 into 1 that dip in the torque curve you see in the lower RPM range will go away. These results are right about where you would be.
 

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Probalbly should look into compresion releases with the 9.81 compression and cam gear instead of cam chain will add 5 tq/hp. They are good also for easing stress and the longevity of the starter. Cheap enough.
I want to do it this winter with some head work and busting compression to 9.81. I'll need to shave .007 " off the deck. or whatever get its to 9.81 Im thinking about the 98" bore and KB flat tops as well. 1.9 exhaust and 1.6 int valves with mild port and polish form local builder. Shiny side up bro.
 

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Probalbly should look into compresion releases with the 9.81 compression and cam gear instead of cam chain will add 5 tq/hp. They are good also for easing stress and the longevity of the starter. Cheap enough.
I want to do it this winter with some head work and busting compression to 9.81. I'll need to shave .007 " off the deck. or whatever get its to 9.81 Im thinking about the 98" bore and KB flat tops as well. 1.9 exhaust and 1.6 int valves with mild port and polish form local builder. Shiny side up bro.

Didnt realize gear drive would free up that much power but I cant use them anyways do to crank runout on my 06.
 
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