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Pig: '79 242 16vT

Got a couple things done and decided to take pictures for once. Installed an NPR, backed off timing to 15* at idle, loosened the MBC a hair (it was pinging at above 13 PSI). Runs great now, up to the point where it somehow peaks at higher boost and the thing decides to cut timing at like 17 psi (it was 15.5 max before...guess less timing means more boost? Does the NPR somehow mess significantly with the pressure ratio? Does 2.2 even have some sort of fuel cut or ignition retard?? ****ing thing went off like a shotgun...thought I grenaded the block, hooooly crap! Anyway, I'll move to an MBC with a softer spring as this once is as loose as it will go.

Aaaaanyway, I'm sort of happy with the fit, and really looking forward to securing the thing a little better. Not a fan of it resting on the core support without any grommets. May have to resort to the wood block method used on 740Ts. Oh yeah, Dying to give the engine bay a cleanup. Injector leaked a few months and caused a bit of "heat" resulting in a sooty mess. Ugh.










Oh yeah, and pic of the Truetrac's box!

 
Saw a picture of your ride, and I bought dumbo mirrors to match. Sleek car man...and mad jealous of the truetrac
 
Saw a picture of your ride, and I bought dumbo mirrors to match. Sleek car man...and mad jealous of the truetrac

Thanks dude! The chrome mirrors work really well with all the polished steel on the exterior :)

Also, figured out the spark cut thing. I maxed the MAF. Saw 16 psi on first and backed out. Before the NPR it never saw more than 12 in first. At all. This is gooooood.


That true trac wont leave the box before you destroy the car in one way or another

Bitch puh-lease.
 
So setting boost is more of a pain than expected. Springs in both of my MBCs are too short/stiff...what a PITA. May be time to upgrade to an EBC.

Who's got any experience with closed loop boost controllers?
 
Does the NPR somehow mess significantly with the pressure ratio?

To answer your question from a few posts back: it depends.

It looks like your boost reference line for the wastegate actuator is referenced from the intake manifold plenum, behind the throttle body. If so, that means that your boost controller doesn't care what happens between the compressor and the manifold. It should keep peak boost at the same point, assuming you aren't getting boost creep due to a too-small wastegate port. Changing the intercooler to a larger, more efficient unit should lower the pressure drop across the cooler, meaning at the compressor outlet, boost will actually be lower now to make the same final pressure at the manifold. The compressor pressure ratio would go down, turbo speed would go down, and you should be making more power due to cooler charge air temps and less backpressure. Less turbine power required to get to the same intake manifold pressure means less exhaust backpressure required.

If you are referencing boost for the controller from the compressor housing, like via a port near the outlet, then upgrading the intercooler will absolutely alter the final boost pressure in the intake manifold. The turbo won't change how it's operating, you'll just get higher boost in the manifold because you'll be losing less of it along the way.

Can you verify your MBC plumbing and where it's referenced from?
 
Definitely referencing from the intake manifold. I did not expect that much of a delta in boost pressure at all. Alas, here we are.
 
So setting boost is more of a pain than expected. Springs in both of my MBCs are too short/stiff...what a PITA. May be time to upgrade to an EBC.

Strange... I've never had any issue with either of the grainger valve MBC's I've used. Solid boost control, never an issue. Had it at 11psi for a while, now I've had it sitting at 14.5psi.

Mine is inline between the compressor housing and the wastegate actuator with about 2.5" of vacuum line on each end. Not saying it's "right", but it does and has worked well for me for years.
 
Cheap whatever water pump shat the bed. Found a pair of NOS Hepus.

Pretty sure my high idle issue has to do with old/worn/broken throttle body seals and old old old idle valve hoses. Engine bay is crying for a detail; it's disgusting.
 
Got a few more things on the way. Kocksense module, an MS2v3 jumper harness from Lord_Athlon, NOS Hepu B21/23 water pumps, extra spark plugs, and some seals to attempt to cure the crappy idle quality that has plagued this car since day 1. The RSI cam is doing it no favors. Some more things I have picked up to make it a nicer thing to live with on a daily basis.



 
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