Bonneville America Forums Forums Technical Forums Performance Mods 180 degree intakes

Well, I went and did some more changing to my speedy today. I went to the local shop and asked about some pod filters for her and they pulled out a pair of filters that were a bit shorter than the normal ones that they would use if the airbox was removed. they were going to have to order a pair if I wanted the correct ones to fit the carbs and I ended up with these slightly smaller ones for a song and a dance ( they didnt know how they got there and couldnt find a price, so there was no price )so have 180 turn arounds now on my bike. still fidgeting with the jetting. Have TBS needles on order, but currently have stock with 2 shims and 142.5 mains and will need to go to 145's. screws out 2.5 but may turn in a bit due to loading up a bit at idle now. Will post some pics of it and my white valve cover soon.
Mark

Do you have part numbers and pictures?

Be careful that those pods can let enough air through at full bore, some smaller pods might cause problems up near the rev limiter.

I was at a shop looking for new ones a while back and the guy told me the size the larger ones I had were better to use over the smaller ones he had for sale. I had to believe him if he was diverting his sale to someone else.

Well, so far no issues. It pulls great at the top end. If it is dodgy anywhere it is still kinda funky in the midrange. It seems to like the TBS needles much better than stock with a shim. ( too rich but no shim too lean ) So I am running 147.5 mains, tbs needles, and 2.5 turns.

I just had mine on the Dyno for about 25 runs.
With my turn arounds it was noted that I was gaining about 1 hp mid range but at the top rev range I would have a sudden drop off of about 10 hp.
My speedmaster is an EFI.with airbox removal (freak kit)
Waiting for a copy of Dyno graph to be sent to me and I will post.

Turn arounds will now only be used for bike shows

with fi if you have not tweaked the map then you are going way lean up high and thats where the 10hp drop comes from. but that also means with a tune you should have a good lil pickup. do they have powercommanders or tuneboy out yet for the new fi system?

Frank

Actually had Wayne himself from Tuneboy working on it.
Bypassed the O2 sensors and got the mixtures near perfect.
When I get my hands on the Graphs from the day I will post them up.
We were both surprised with the results, don't know if its due to the intake lenghts or some sort of Venturi effect in that high rpm range?

I highly suspect that sharp bend is creating both turbulence and reduced pressure (i.e. vacuum) at the carb throat during open throttle high RPM. I would have been very surprised if you reported other results.

Jack

wayne is the man, does wonders with the rockets and a very nice guy who KNOWS his stuff. cant wait to see the graphs, maybe my mikunis would like the 180 intakes. also any info wayne gave you feel free to share

Frank

EFI Speedmaster with airbox removed and aftermarket pipes.
I don't know how this rates (compares) to standard

56 hp isnt bad. no torque numbers?

actually seems a lil low for no airbox, what pipes and why no tq curve?

Frank

The HP curve is very linear - no mid range blip.
I'm suprised at how fast the hp drops off at the upper end though. Normally the hp is still climbing until the rev limiter is hit. What type of pipes are you running? If they are stock, they could be restricting things a bit. Notice how the AF ratio richens up at the top end.



The EFI units are rated for 61 hp stock (I imagine at the crank) This seems a bit low.

I though 56 was respectable, when I dyno'd mine it put 54 to the tire with Sceptres, K&Ns with rejet, and all nology ignition.

Did you do anything to the EFI mapping?

Nevermind. I saw your other post.

Finally got the graph showing torque.
Doesn't look to bad

not bad. i would like to see the difference with and without the 180 intakes

Frank