BCS mod Vs. MBC

[GatorManTSI]

I am not too sure if this has been posted before or not. I tried doing a search, but found vague info. Anyways, my question is this......

Now that i am installing a Hallman MBC next week, what will I feel differently as opposed to the free BCS mod? Will there be a more stable feeling of HP? Right now with the BCS mod only, I am suffering from Boost spike. With the MBC, this should stop and stay at a "normal" boost level for more consistant HP, correct?

Kind Regards,
G

 

[larryd]

boost spike isnt caused by your BCS. The only thing the MBC will change it is will allow you to change your boost level. The only thing the BCS mod does it add a few lbs of boost.

 

[GatorManTSI]

Ok, I understand the boost spike part....I appreciate that!! BUT, how about the actual HP feeling? I plan on bumping up to about 18 psi. How dramatic of a feeling will this be, and how long through the powerband will this last with the mods I have? Oh, and with an actual boost controller, the spike should be pretty well eliminated, correct?

 

[larryd]

As i said before putting a boost controller on the car will not eliminate boost spike. your turbo isnt spiking because of the BCS mod. You probably have a full exhaust with a stock o2 housing or something right?

 

[98TsiAWD]

Port out your o2 housing, and/or make your wastegate hole a little bigger. Or you could save yourself money and a hassle and goto www.rnrracing.com and order a 3" o2 elim downpipe. Then sell your RRE downpipe to get most of your money back.

 

[DeezNutsForYou]

You would still have to buy an external wastegat, you can't just get a O2 elem downpipe with out somewhere for it to go.

 

[98TsiAWD]

Originally posted by DeezNutsForYou
You would still have to buy an external wastegat, you can't just get a O2 elem downpipe with out somewhere for it to go.

Umm, not you wouldnt, wastegates and o2 are 2 completely different things. You do not need an external wastegate. And the 02 elim. downpipe just gets rid of the o2 housing, an o2 bung to screw the o2 sensor into is still there...

 

[SPEEDY]

I get some boost spike with my RRE MBC and my O2 housing has had the hell ported out of it. I thought that porting the O2 housing was to help defend against boost creep, not boost spike. I worry more about boost creep than I do spike. Example... I'm currently running 20 psi on my ported Big28 but it spikes to around 22 to 23 psi then settles at 20 psi.

 

[Enigma_Man]

Actually Larry, some people have cured their boost spike just by installing an MBC. Something about the BCS not being able to switch quick enough, or flow enough I think... Boost spike can also be caused by a slow-to-react boost controller (the BCS).

It's not guaranteed to work, but it could possibly help. If you're going to get one anyway, then try it and let us know.

Originally posted by larryd
As i said before putting a boost controller on the car will not eliminate boost spike. your turbo isnt spiking because of the BCS mod. You probably have a full exhaust with a stock o2 housing or something right?

And about the O2 Eliminator thing. That's probably the worst term for it. It doesn't eliminate the O2 sensor or the wastegate. It's basically a downpipe and O2 sensor housing all as one piece... It'd be the same as buying an aftermarket O2 housing, a downpipe, and welding them together. What it "eliminates" is the need to buy the two pieces separately.

GatorMan, you could _possibly_ turn the pressure up to 18 PSI or so.. I would be very careful though, because by your mods list, it looks like you still have the stock injectors, and no sort of datalogging or fuel control. You have a good fuel pump, which is good. I would be very careful, cause you could completely wreck your engine with the mods you do have. I would invest in a datalogger, then keep turning the boost up little by little until it starts to knock, then back off a few PSI. Also, I didn't see mention of a boost gauge in your mods list, but I'm assuming you have one (if you don't, get one NOW, because the stock one is not accurate at all). I would take a guess and say that 15 psi without monitoring would be "safe" but do you want to leave it to chance like that?

Hope that helps some,
-Jesse