I just got a rebuilt 865 in my q8. 44mm carbs, bpipe, skat pump, msd. Now im still running it in but the bottom end feels very simillar to my 701 that had some work done to it. Dont get me wrong the top end is insane i cant even hang on but bottom end i must admit i am dissapointed. What is my next move to get the bottom end alive? TL, bigger carbs, prop, comp??
xs865 bottom end power??
- Thread starter dcanna
- Start date
- Location
- Victoria BC
is your pipe tuned right for bottom end?
dont know i left it up to the engine builder, was doing some research and it looks like i need a limited chamber with a stinger mod?? its gonna cost a fair bit to get that sent over from US to AUS, is it possible to get the same thing done locally? or better spend the money on an ignition or carbs
Tyrant1919
Site Supporter
- Location
- Washington, DC
I used to have 44s and a bpipe. Upgraded to PFP and 48s in one go. What I would do in your situation, sell your B-pipe and find a used power factor.
Matts right...SS engines need the right prop to get them spooled up and hit. Bottom end is not their forte...they need RPM's. You can go about it backwards and try larger bore exit nozzle and or smaller tail cone to off load the pump quicker.
Sent from yo' momma's house...on her iphone
Sent from yo' momma's house...on her iphone
- Location
- Largo, Fl
Recommended pump setup (minimum) is 14/17 C75 (big hub) with pump stuffer. I would bore the nozzle too.
- Location
- sask, canada
I had a 10/17 big hub impeller with stubby cone in a Solas mag pump when I had a xs865 in a Trinity Matrix and I thought it had really good bottom end power. That was with a single Novi 46, B pipe and stock electronics with rev limiter removed.
N3vrSat1sfied
Military Member
- Location
- Fort Worth, TX
Timing sure helps these motors ,i thought the hx3 on curve 2 really woke the 865 up and got the motor spun up and on the pipe quickly for a charging system.but if you didn't change the prop from a previous smaller motor ,chances are your burning right thru the low end pitch of the prop .on mine at first ,it couldn't keep up with the 10/16 hooker that i was previously running so i have gone up to a 13/18 hooker in my 144 solas pump and its defiantly not over propped but hits nice .But also i am running tl & pfp though ,so for your set up ,you might want to start at a 12/18 or 11/17(hooker) or a low end oriented prop and i bet you really start to tap into its potential . what are your jet specs on those 44's ? be careful not giving these motors the proper amount of fuel delivery can be costly in the end .
OCD Solutions
Original, Clean and Dependable Solutions
- Location
- Rentz, GA
Bigger carbs and opening up that pipe and manifold are really going to help. Also, how much air does your hood/pole pass?
I'm running a 14/19 in a 144 setback mag with a stock nozzle and it hits hard right off the bottom. ScottS runs a 13/19 or 13/18 in a 144 Solas mag and his is a little softer off the bottom. We each tried the 10/16 and 11/17 and went back to the Skat swirls.
Timing may not play as big a part as you think. It definitely contributes but IMO, won't be the smoking gun you're looking for. I never tried an enhancer but I did program a similar curve in my Epic and detuned it even further for my surf curve. I've taken quite a bit of timing out of the initial curve and it still hits hard in the surf. My flatwater curve peaks at 32deg and my surf curve is down around 21deg and it's still a handful at times and pulls harder than other S865's in our group.
The waterbox and stinger injection will have an affect on bottom end as well. If the waterbox is loaded up with water then it won't come alive until it clears out as well. I run the ATP waterbox very dry which is a big reason I get the bottom I get. I also ceramic coated my entire b-pipe for whatever that's worth.
I'm running a 14/19 in a 144 setback mag with a stock nozzle and it hits hard right off the bottom. ScottS runs a 13/19 or 13/18 in a 144 Solas mag and his is a little softer off the bottom. We each tried the 10/16 and 11/17 and went back to the Skat swirls.
Timing may not play as big a part as you think. It definitely contributes but IMO, won't be the smoking gun you're looking for. I never tried an enhancer but I did program a similar curve in my Epic and detuned it even further for my surf curve. I've taken quite a bit of timing out of the initial curve and it still hits hard in the surf. My flatwater curve peaks at 32deg and my surf curve is down around 21deg and it's still a handful at times and pulls harder than other S865's in our group.
The waterbox and stinger injection will have an affect on bottom end as well. If the waterbox is loaded up with water then it won't come alive until it clears out as well. I run the ATP waterbox very dry which is a big reason I get the bottom I get. I also ceramic coated my entire b-pipe for whatever that's worth.
OCD Solutions
Original, Clean and Dependable Solutions
- Location
- Rentz, GA
What prop are you running now and where do you have the screws set for the B-pipe?