Safe boost on NA8

MXkal · Postby **MXkal** » Tue Jun 22, 2010 2:26 pm

Hi guys i got bored the other day looking at my unregod NA8 with NB8B motor i just put in it.. I had alot of spare parts laying around such as a s15 t28 turbos, intercoolers and bovs.
So finally i started pulling down the NA and starting fabbing up a turbo manifold and other random bits, Just wanting to know what sort of boost would be acceptable to run on a stock NA8 ecu with NB8B motor?
Im not looking for huge power or anything just something to keep me entertained for a while..
Thanks..

broady · Postby **broady** » Tue Jun 22, 2010 2:28 pm

Kal probably not much, as you know the 8B engine has high compression - maybe have a look at what SPs are doing because they were based on the BP-Z3 engine

Benny · Postby **Benny** » Tue Jun 22, 2010 6:12 pm

Without doing something with the computer, you'll hardly be able to run any boost.
However, if you do something with the computer, apart from chucking it out, you can safely run 8lbs (a bit over half an atmosphere) of boost with little chance of doing any harm.
The 8lbs is about the limit you can go before you start to bend rods.

Novice1 · Postby **Novice1** » Tue Jun 22, 2010 8:18 pm

My NB8A as an e-boost2. Mostly run on low boost, I would say 99 percent of the time.

High boost 14 psi 172 kw atw and running on the rich side.

Cheers Novice1

MXkal · Postby **MXkal** » Wed Jun 23, 2010 2:30 am

The actuator is the stock 7psi one i think

Ive got one of those SAFC NEOs somewhere in my workshop i got for another one of my cars, Does anyone run these for boosted MXs?

GS · Postby GS » Wed Jun 23, 2010 6:50 pm

MXkal wrote:The actuator is the stock 7psi one i think
Ive got one of those SAFC NEOs somewhere in my workshop i got for another one of my cars, Does anyone run these for boosted MXs?

Is the SAFC just an interceptor that allows adjustment of your air/fuel mix? Or does it give you timing control as well? If it just controls the air/fuel then you'll probably have problems with your timing if you try running a turbo with the standard ECU.

I believe retarding the timing on a NB8B engine will be difficult if you're keeping the factory ECU (unlike the B6 engine which allows you to easily rotate the CAS to adjust the timing). A standalone ECU would be the way to go.

MXkal · Postby **MXkal** » Thu Jun 24, 2010 1:46 am

the CAS on my NB8 motor is the same setup as the B6s ive seen as ive used the rear mounted CAS along with the valve cover off a NA8 motor.
I would of thought you would just retard the timing over the whole rpm range, Would be a pig off boost tho

ampz · Postby **ampz** » Fri Jun 25, 2010 10:18 am

MXKal

If you run a RRFPR (rising rate fuel pressure regulator) you should get enough fuel out of the stock pump and injectors for wastegate boost (up to 8 psi with creep) off the standard ecu.

Using something like a BIPES timing interceptor will allow you to run safe timing across the board, otherwise you can adjust the CAS to 6-8 deg at idle and minimise pinging (it will be a pig off boost).

Both those items will cost around $100 each (new for the FPR and used for the bipes), use a wideband o2 to tune the FPR.

The other option is emanage/link as interceptors of any sort of programmable ecu as standalone.
the SAFC if i recall does not like the AFM signal (at least the NA6 one, dunno about the NA8) as it was inverse to normal. If you have a hotwire MAF you may get away with it, but I haven't really played with one.

Cheers
NJ