BBM Mod... worth it?

santoitaliano · 01-02-2005, 07:41 PM

hey all...

is the BBM mod worth it... any feedback by those that have done it?

much kw increase? torque increase..

basically any info on what is involved?

cheers

DentEd XR8 · 01-02-2005, 08:10 PM

My mate just recently did it too his ED XR6, noticed SFA difference, if anything it only seems to rev easier. Haven't had it on a dyno yet either.

He ended up spending $200 to get everything but can't use his XR6 Fuel Reg cos there's no room for it. Had to replace the manifold (new gasket), injector rail (used existing injectors), got the airbox/ducting and snorkel, also had to cut the radiator shroud for the snorkel, he also changed the top thermostat housing and hose. The loom isnt necessary, the exisiting loom fits straight on if you undo the tape and retape it after it's all connected, I can't remember all the other little fiddly bits but it was going within an hour

Psycho Chicken · 01-02-2005, 08:15 PM

You won't gain any power from it. It's all bottom end torque.

santoitaliano · 01-02-2005, 08:18 PM

sounds like a waste of time for nothin..

thanks

needturbo6 · 01-02-2005, 08:20 PM

Quote:

Originally Posted by DentEd XR8

My mate just recently did it too his ED XR6, noticed SFA difference, if anything it only seems to rev easier. Haven't had it on a dyno yet either.

He ended up spending $200 to get everything but can't use his XR6 Fuel Reg cos there's no room for it. Had to replace the manifold (new gasket), injector rail (used existing injectors), got the airbox/ducting and snorkel, also had to cut the radiator shroud for the snorkel, he also changed the top thermostat housing and hose. The loom isnt necessary, the exisiting loom fits straight on if you undo the tape and retape it after it's all connected, I can't remember all the other little fiddly bits but it was going within an hour

what did he use to switch the intake runner butterflys?

DentEd XR8 · 01-02-2005, 08:24 PM

Nothing yet, he's in the process of getting a vacuum switch and rpm switch and hooking it all up properly. He thinks that by getting that working it's gonna make a huge difference but he's going to be hugely dissapointed.

We've tried locking it in both long and short runners (using a zip tie) and I reckon it doesnt make a difference either way.

Thanatos · 01-02-2005, 08:30 PM

Unless you are going to figure out a way to switch the runners, then don't bother.

Top end is very similar, but a gain can be felt down low. It is a great compliment to a big cam, as it compensates for some of the low down torque loss.

Having said that, Santo, your cam is all for low end power anyway, so i don't think you would really see all that much gain from it.

TIKFD6 · 01-02-2005, 08:46 PM

Jaycar has a new Kit, Frequency switch, that will do the job very nicely.
Its what im going to use when i do the mod on mine.

Dented XR8 what cam is your mate running?

needturbo6 · 01-02-2005, 08:49 PM

Quote:

Originally Posted by Thanatos

Having said that, Santo, your cam is all for low end power anyway, so i don't think you would really see all that much gain from it.

i disagree with you there thanatos

_2: , IMO it would compliment the cam, as the basic rule to modifying motors is to get everything matched as best as possible and to a certain rev range. ie. short runners for high rpm power and long runners for low rpm power.

DentEd XR8 · 01-02-2005, 09:18 PM

Quote:

Originally Posted by TIKFD6

Jaycar has a new Kit, Frequency switch, that will do the job very nicely.
Its what im going to use when i do the mod on mine.

Dented XR8 what cam is your mate running?

Just the standard XR6 cam

TIKFD6 · 01-02-2005, 09:29 PM

Once he gets the switching working he will notice an improvment.

stockstandard · 01-02-2005, 10:04 PM

Quote:

Originally Posted by needturbo6

i disagree with you there thanatos , IMO it would compliment the cam, as the basic rule to modifying motors is to get everything matched as best as possible and to a certain rev range. ie. short runners for high rpm power and long runners for low rpm power.

I agree, but your bottom end is already strong. It will have a much more noticable gains on an engine that is cammed up and has lost bottom end power because you will be improving the engine weak point.

The BBM improves low end power with no real loss anywhere else. It probably wont help much on the 1/4, and isnt going to improve the dyno, but it will make the car a little stronger on the road.

Unfortunately we dont off the shelf aftermarket intakes for our cars like the v8 guys have, but IMO (and I think most will agree), the BBM is the best for NA applications, and EB/ED is quite ofthen the best for forced induction applications, just because it is easier to plumb.

Oh, and I drove around for a while with the with the BBM not working (switching mechanism came apart) and it just didnt feel right. The car will drive better when it is all working as it should be.

INJECTED_250 · 01-02-2005, 10:18 PM

hey intake noise games then... the ea-ed one sounds 10 times better

Sundeep · 01-02-2005, 10:21 PM

I did it but noticed barely any improvement over the EA manifold, then again I didn't get it switching and used it mostly on gas. It was a little bit punchier downlow but died in the **** up top. I put in a EB2 head and EF cam at pretty much the same time as well.

The main difference I noticed was that the engine revved and sounded a lot smoother.

I wouldn't do it again though.

Sundeep

ssj_jaypee · 02-02-2005, 12:12 AM

What the hell are we all talking about here?

Never heard of BBM but if it can help me in my quest for more power I'd like to know about it! :evil_laug

DentEd XR8 · 02-02-2005, 12:27 AM

BroadBand Manifold, basically the inlet manifold has two paths the air can travel, the longer path for the lower rpm promotes more torque and then it switches to short runners at higher RPM's for better top end.

These manifolds are standard on EF onwards.

I just might also mention the new Hyundai Tucson has a 3 stage broadband manifold.

Thanatos · 03-02-2005, 10:04 AM

Quote:

Originally Posted by stockstandard

I agree, but your bottom end is already strong. It will have a much more noticable gains on an engine that is cammed up and has lost bottom end power because you will be improving the engine weak point.

This is basically what i was trying to say ;)

Cars that already have power down low (e.g. 'towing' cams, stock cams, etc) all seem to say that they didn't notice HUGE gains from fitting a BBM. Cars with slightly more wild cams (e.g. Myself, most Dev-5 cars, etc.) seem to benefit more...

Sox · 03-02-2005, 12:53 PM

Quote:

Originally Posted by stockstandard

I agree, but your bottom end is already strong. It will have a much more noticable gains on an engine that is cammed up and has lost bottom end power because you will be improving the engine weak point.

The BBM improves low end power with no real loss anywhere else. It probably wont help much on the 1/4, and isnt going to improve the dyno, but it will make the car a little stronger on the road.

Unfortunately we dont off the shelf aftermarket intakes for our cars like the v8 guys have, but IMO (and I think most will agree), the BBM is the best for NA applications, and EB/ED is quite ofthen the best for forced induction applications, just because it is easier to plumb.

Oh, and I drove around for a while with the with the BBM not working (switching mechanism came apart) and it just didnt feel right. The car will drive better when it is all working as it should be.

Ignore the others and listen to this bloke, it is basically what I would have said.
The BBM has no downside, yet it increases power and throttle response below 3500rpm outta site.
IMO, it is the best mod aside from a camshaft.
To did it properly though, you will need the correct ECU.

Just do it.

Rick.