upping boost on a sohc jrsc?

[Tad3d]

Hi,
what would you recommend to get if I wanted
to go up to 8or9psi of boost on my sohc civic?

i'm currently running 6psi with the jr fmu and JR map controller, d15b vtec engine.

The alternator stepper pulley only works for bseries correct?

So basically I can either get a bigger crank or smaller SC pulley? What would you guys reommend?

I like the sound of a smaller SC pulley,
but I have heard that belt slipping issues can come up with that setup?

A bigger crank would work, but I don't like the idea of it being heavier/harder to turn(even more parasitic SC drain on the engine).

Also when I'm upgrading my fuel management,
i'll probably go with bigger injectors and uberdata. So the FMU is gone, but should I ditch the JR map sensor as well?

[JRCivic]

I think that the 8 psi blower pulley would be fine... there are lots of users out there that have not experienced any problems using a "one step" smaller pulley. However, I do NOT suggest you go any smaller on the blower than a 3.4" pulley... if you want more boost than 8 psi, you need to increase the crank pulley diameter.

As for the JR MAP mod... you cannot use it with Uberdata, or any other type of engine management because it is a voltage clamp. You can use the plate portion of the unit to gather manifold pressure up to 11psi if necessary... the electronic portion must be removed.

[JRciv]

The MAP Controller allows the stock map sensor to read boost by directing the vacuum hose to the intake manifold.

So when you ditch the MAP Controller and switch to uberdata, can the stock map sensor still read boost or do you need to buy an aftermarket (such as GM) MAP sensor?

[Jaker]

The stock MAP will "accept" and read up to about 10.65 lbs of boost. I personally have been running 10 lbs of boost through the stock map for about 3 months now, and I'm sure many many people have been doing it or alot longer than that.

[Tad3d]

Originally posted by Jaker:
The stock MAP will "accept" and read up to about 10.65 lbs of boost. I personally have been running 10 lbs of boost through the stock map for about 3 months now, and I'm sure many many people have been doing it or alot longer than that.

<font size="2" face="Verdana, Helvetica, sans-serif">but won't you get a CEL if the stock map see's boost? without anything to prevent that cel?
(according to JR the jr map will prevent said cel).

[Tad3d]

Originally posted by JRCivic:
I think that the 8 psi blower pulley would be fine... there are lots of users out there that have not experienced any problems using a "one step" smaller pulley. However, I do NOT suggest you go any smaller on the blower than a 3.4" pulley... if you want more boost than 8 psi, you need to increase the crank pulley diameter.

<font size="2" face="Verdana, Helvetica, sans-serif">so how much boost will I make with a 3.4" pulley?
the stock pulley is 3.8"

[Jaker]

The OEM ECU won't kick a MAP code unless it sees more than approx. 11 psi of boost (I think its just slightly less than 11).

I'm running the 3.4" blower pulley and a 6.4" crank pulley (unknown Honda OEM origin) and I see 10 psi at 7,000 rpm.

[Jaker]

I'm also running a SOHC (D16A6). The ECU will not throw a code unless the MAP sees more than the 11 psi (approx.) limit.

[Tad3d]

ok thanks,
and remember i'm running a sohc,
so 3.4" wont produce the same for me as it would
for a bseries(i dont think).

i was always under the impression the stock map
could read up to 10-11psi, just it'll throw a code,
and more than that and it straight won't work!

[Tad3d]

ok so how much boost will that 3.4" pulley make on my sohc with stock crank?

thnx.