Unusual LH2.2 + EZK question

First of all, I want to say that I'm a long time lurker, first time poster. I have gleaned that starting a "how do I turbo my B230F" thread or any one of a number of other thoroughly covered topics is a quick way to get real unpopular on here. I've also been looking through some earlier threads on the subject for quite some time now and have at least acquired a pretty good inventory of the things I don't know, which I suppose is a good first step. I haven't been able to find anyone who has asked this particular question though, so here goes.

On my '85 240 DL (B230F), if I were to replace the Chrysler ICU with the EZK unit (as described here: http://forums.turbobricks.com/showthread.php?t=129382)...

...and if I were to swap the ECU and ICU units from a turbo car (541 LH and 012 EZK, I believe?) and otherwise prepare the car for a +T install (red-top injectors etc.)...

...can you think of any reason why the engine control system would't work with a SUPERCHARGER? Ooooooh yeah, I went there.

Assume the following things are true:
-I can find somewhere to stuff a supercharger, intercooler, drive belts and associated plumbing
-Stock NA intake, MAF and exhaust manifold.
-The supercharger draws through the MAF and blows through the throttle body.
-The supercharger is properly sized for the engine and is set up to put out roughly the same peak boost as the stock turbo (I'm thinking somewhere in the realm of 5-8psi)
-I run an intercooler of some kind (although I would be interested to hear your opinions on whether or not this would be necessary)
-I leave the engine internals alone.
-I do not otherwise cock up the installation

Now, I know the reason no one appears to have asked this question before is that supercharging a B230F is an exceedingly silly thing to do. My reasons for contemplating it aren't that I think it will be easier than a +T, or that I think I am going to get a bitchin quarter mile screamer out of it or anything like that. I want to do it just because I think it would be fun and an interesting challenge. Besides, everybody puts turbos in these things. Boooooring.

I guess my question is regarding how the ECU/ICU is mapped. Even though my imaginary supercharger would put out roughly the same boost pressure as the stock turbo, it would be delivering it on a completely different curve (lots more than a turbo at low RPM, probably somewhat less than a turbo at high RPM). The obvious way to get around this would be to use a centrifugal supercharger, but those things are hideously expensive and hard to find. Would the turbo engine control stuff be able to figure out what's going on, or would I be looking at a megasquirt or something similar?

In case anyone is wondering, my tentative napkin sketch plan is to pull the nonfunctioning AC system out of my car, thereby freeing us a space in front of the radiator for an intercooler and a nice empty spot on the driver side of the engine for a small blower. Based on my careful eyecrometer measurements, I think I could get an SC12 or SC14 from a Previa in there, or possibly the unit out of a Cooper S (possibly a bit small) or one of several modern Mercs (I believe the mid 2000's C series had a neat little screw type that would probably work). I'd leave the airbox and MAF where they are, route the plumbing down to the blower and up to the stock intake. Not sure exactly how/if I am going to be able stuff the intercooler piping in there somewhere, but I think I could figure something out. The goal is modest performance (somewhere in the 150hp to 180hp range, and hopefully a decent bump in low end torque), fairly minimal modifications to the car and extremely low cost. I'm also planning on making it revertible to stock in an afternoon should I determine that yes, indeed supercharging my 240 is a stupid idea. I'm not planning on running monster boost or otherwise trying to blow the thing up, since it's my old and well loved daily driver.

So, what do you guys think? Am I on to something? Am I bonkers? Sorry for the wall of text.

TL/DR - but some have supercharged redblocks before. Can't remember the name of the one member here (Blown240?) who did this with a Toyota supercharger, but his 240 was also kinda rat-rod and had a flamethrowing exhaust. It was sweet.

I don't see why turbo LH2.2 wouldn't be able to deal with it, within reason anyway. Forced induction is forced induction right? The Bosch LH2.2 'turbo' system, in theory anyway, shouldn't know the difference between a supercharger and a turbo; either way it's producing a positive charge in the intake tract and that system was designed to deal with it to a point. The sensors and modules don't know what they're bolted to, they just read within a certain range for specified operating parameters, and report those signals to the ECU...which again, doesn't know what it's controlling, just that it is controlling it and trying to maintain status quo.

Ideally, you'd step up to a programmable EMS (MegaSquirt, AEM, etc.) if you decide to get really silly with it. Or custom mapped LH2.4 maybe.


Just my $0.02

I'm thinking that the LH2.2 computer would be fine, simple MAP referenced table, but I'm not too familiar with them though. The EZK, I have no clue, if the timing table is MAP referenced you should be ok, and since people run so many different turbos and they all spool at different rates I'd expect the EZK to handle all this pretty well.

It will be fine. The engine management won't care what kind of pump is blowing air into the engine and is too dumb to figure it out anyway.

Sounds like a fun project, be sure to keep us posted and post lots of pictures.

This ^ x2

So the prevailing opinion is that it should probably work? I'm mostly concerned about the timing, since the fuel delivery computer is (as far as I know) mostly just controlled by flow past the MAF and some limited feedback from the o2 sensor. There's no rpm specific map, as far as I know. Specifically, I'm worried that the timing might be too advanced at low rpm, since the turbo makes no real boost then. Thoughts?

I've been looking at my dead AC compressor for a while and wandering down the same sort of path you're on, Fjergus. While I have nothing particularly techie to add, I will be following this with interest.

Well, it will be a little bit before I do much of anything on this. I have several other projects I should probably finish before I start another one. I'll post again when I start working on it though.

Are you looking at a roots or centrifugal blower?

Wouldn't be too concerned about timing, especially with a centrifugal unit. Stock EZK is very conservatively mapped. Roots may be an issue as you could be seeing boost right off idle. There are people still futzing with EZK117 chips. They may be able to help once you get it running. Paging Sbabbs and thelostartof!

Centrifugal would be nice for a number of reasons, but since there has never been a car (that I am aware of) that came with one installed from the factory, junkyard options are pretty limited. I'm not about to drop $5000 to supercharge my $800 car. I'm looking at the SC14 out of a 94+ Toyota Previa, which is a roots type. It's about the right displacement and external size, and most importantly I think I could find one on a wrecked Previa for a few hundred duckets if I looked hard enough.

Extremely low cost and extreme ease of installation/removal is what I'm going for here. That means primarily easily sourced OEM parts from commonly scrapped cars. I am obviously going to have to fabricate the plumbing and mounting brackets, but I want as much as possible of the rest of it to come from the junkyard.

Also important to note here is that the car I'm planning on putting it on is my daily driver, so I want to be able to tinker with it without permanently cocking anything up in case I determine that yes, this was indeed a poor decision. That's why I want to be able to swap the whole system in or out in a few hours if need be.

For your argument I would recommend against the SC and go with a turbo. Easy enough to plug some oil ports. Easier even than sorting out an intake manifold that will accommodate a roots type blower. A 740/940 turbo should have everything you need.

Seriously, experimenting like this in a car you rely on is bad juju.

Fair enough. I know I could do a turbo, but I want to do something a little more interesting/challenging/fun. I'm really not worried about fabbing up the plumbing: I have a mill for cutting flanges and a couple good buddies who are extremely good TIG welders. There are plenty of very valid arguments for not doing this, I know.

Anyhoo, I'll keep you guys posted once I actually start moving in this direction. Like I said, I've got a number of other projects I should probably work on first. Thanks for the input!

Twin charge it, super and turbo

I like where your head's at.

For the most part a Mass Air Flow system the ECU doesn't care how you get the air into the engine, it will calculate air mass based on air metered past the sensor no matter what.

The areas where you could run into problems is the transient fueling or your acceleration fuel and spark. "Time to torque" on a positive displacement supercharger is several milliseconds faster than on a turbo.

What does this mean for the calibration? It might need an extra shot of fuel when you whack the throttle in order to keep the engine from going lean until the mass air meter can catch up.

When it comes to transient power, the devil is in the details. The ability to deal with issues like this makes the difference between a really well running car and a crappy one that you probably won't want to drive. You should be able to modify the accel table with a chip, if not then an aftermarket ECU would definitely be able to resolve this.

I don't know much about the Previa blowers, although I did see one while I worked at Eaton and they ran one on a performance stand. I think it performed okay, but it was very much a low speed/low boost blower (The previa was only rated at 158hp). If you can get your hands on an Eaton R900 (300-ish HP) or R1320 (450-ish HP), that would be the cats meow, but I think you might exceed your horsepower target with those... Otherwise an Eaton M62 is still an excellent performing blower (came on the Cobalt SS) and had performance efficiencies in the 70% range. The housing is a fairly generic style that lends itself to adapting it to other applications.

I would recommend intercooling any super/turbocharged car. The downside to supercharging with a positive displacement supercharger is that an air to air intercooler sort of becomes a "speaker" and in some cases amplifies the blower whine, this is why you see air to water intercoolers on OE supercharged vehicles.

Another issue you'll need to deal with is placement of the throttle body. If you don't move the throttle body to the inlet of the supercharger, you'll need a big blowoff valve or you'll bend the throttle blades when you snap the throttle shut after a WOT/Full Boost pull. Putting the throttle body before the supercharger also limits the air mass inside the supercharger so that it's not recirculating very much air while the intake is under vacuum at partial load (i.e. cruise), this helps with fuel economy.

Maybe that was too much info... <shrug> But yeah, it should work.

from a management stand point, it'll work fine. go for it.

VB242 said:

Twin charge it, super and turbo

Click to expand...

Quad turbo is established as the most sensible way to impress people so I say quad turbo AND supercharge it..


All whims must be discussed fully.

tt460 said:

I don't know much about the Previa blowers, although I did see one while I worked at Eaton and they ran one on a performance stand. I think it performed okay, but it was very much a low speed/low boost blower (The previa was only rated at 158hp). If you can get your hands on an Eaton R900 (300-ish HP) or R1320 (450-ish HP), that would be the cats meow, but I think you might exceed your horsepower target with those... Otherwise an Eaton M62 is still an excellent performing blower (came on the Cobalt SS) and had performance efficiencies in the 70% range. The housing is a fairly generic style that lends itself to adapting it to other applications.

Click to expand...

My main reason for looking into a Previa supercharger is cost; they're dirt cheap. Like I said earlier, I want to do this whole thing as cheaply as possible. I'm only looking for 5psi or so and the toyota unit should deliver that just fine. I've also been looking into an Eaton m62 though, since they were OEM on a bunch of cars (the Cobalt you mentioned as well as a ton of Mercs and even a Saturn or two) and are also super low cost. They're also serviceable, I believe.

tt460 said:

The downside to supercharging with a positive displacement supercharger is that an air to air intercooler sort of becomes a "speaker" and in some cases amplifies the blower whine, this is why you see air to water intercoolers on OE supercharged vehicles.

Click to expand...

I'm ok with that...

What do you think about mounting an air-air intercooler somewhere under the car? Obviously it would have to be high enough up to keep it from getting whacked with road debris, and I'd have to figure out a way to direct clean (from an aerodynamic perspective, not a dirt perspective) air flow to it, but it would make mounting the thing waaaaay easier if I could stuff it in there somewhere. Less plumbing too, so hopefully the delay would be less.

tt460 said:

Another issue you'll need to deal with is placement of the throttle body. If you don't move the throttle body to the inlet of the supercharger, you'll need a big blowoff valve or you'll bend the throttle blades when you snap the throttle shut after a WOT/Full Boost pull. Putting the throttle body before the supercharger also limits the air mass inside the supercharger so that it's not recirculating very much air while the intake is under vacuum at partial load (i.e. cruise), this helps with fuel economy.

Click to expand...

Wouldn't running the throttle before the blower cause massive amounts of vacuum behind the throttle plate? Would that cause problems with vacuum operated accessories?

I'd like to use the stock throttle body if at all possible. Moving it requires relocating vacuum lines, idle air control valve, throttle position sensor, etc. I'd rather avoid that if I can.

Both the Previa blower and the ones on some of the Mercs have neat-o little air conditioner pump style clutches on them. I was actually considering installing a monster bypass system (like 2 inches or more) and wiring the clutch up to a switch in the cabin so I could turn the supercharger off and run NA if I wanted to. Not sure how that would work with a turbo ECU, but it would be kinda neat for highway cruising. Plus, how rad would having a big red switch on the dash that says "SUPERCHARGER" be?

Speaking of bypass valves, is there any problem with running them with a hotwire MAF? I'm concerned that when the valve opens, the release of pressure might actually cause the air flow to reverse through the MAF momentarily and confuse the hell out of it. Is that a problem?

@tt460, here's kinda what I'm thinking of in terms of plumbing:

What do you think? I have never played around with supercharger systems before.

You should put the bypass valve between the supercharger and the intercooler, this will help with your reverse MAF airflow issue. Mine is between the turbo and the intercooler works great, most of the factory turbo cars on here have the CBV built into the turbo.