1979 FIAT X1/9 Turbo K20 Conversion, or "I Did it My Way," or "my God, What Have I Done?"

OK, those who made the suggestion have me onboard with pump gas as the primary fuel and supplementary methanol injection.  

On that note, I wonder about implementation of the methanol injection.  It seems that, in order to optimize the chilling effect of the methanol, one would want to inject the methanol upstream of the intake manifold to give the methanol space to integrate with the air charge and time to absorb heat.  It also seems that putting the methanol through the intercooler could give the methanol a chance to fall out.  On the other hand, running it through the intercooler might also assist in cooling.  I don't know.  I haven't done this before, and it seems like it could go either way.  

Below is a CAD (crude-ass drawing) of what I have in mind for the intake system.  Would it work well to inject the methanol upstream of the intercooler, or is that a no-no?  Should I build the intake system more conventional so as to give the methanol space and time to spread out and do its work?  

Typically you see the meth injected after the IC, but before the throttle body and intake temp sensor. I believe the nozzles and injection systems aren't appropriate for the vacuum seen in the intake post-throttle. 

You don't want to inject before your intercooler to avoid water pooling anywhere in the intake tract. 

Definitely no meth/water through the MAF if you're using one. The intake air temp sensor needs to see the injected mix in order to trigger the ECU to adjust timing, but note that meth will evaporate almost immediately upon injecting and result in the greatest IAT drop, but water will do more to lower in-cylinder temps since it won't evaporate as quickly.

This is something you don't need to overthink too much: if you install it without a lot of data or planning, you get lower IAT and cylinder temps. Win. If you want to squeeze out every bit of power, you'll need to closely monitor pre-detonation and see how much timing advance you can add when injecting, which is where you'll see the most benefit.

Mezzanine said:

Typically you see the meth injected after the IC, but before the throttle body and intake temp sensor. I believe the nozzles and injection systems aren't appropriate for the vacuum seen in the intake post-throttle. 

That is what I would expect.  And that is why I asked if I might have to rethink my ultra simple intake design laid out above; there is no place in the design above that is both upstream of the TB and downstream of the IC.  

It's easy enough to build a more conventional intake system, either ATA or ATW.  I just happen to like the shortest intake tract possible and like the idea of not repeatedly squeezing the charge air through tubes, then into a larger volume, then back to tubes, and so on.  I was inspired when I saw the Renault R5 Turbo's intake design, in which the intercooler serves as the intake plenum.  

Is there any other reason for putting the throttle upstream of the IC? Sorry I missed that detail in the sketch...Adding the IC after the throttle will do some really interesting things to your throttle response, and I suspect few of them will be positive. 

I love solving problems myself as much as the next person, but this is a place where I would have a hard time believing that I could be smarter or come up with a better solution than the 99.9% of tuners and manufacturers out there that put the IC upstream of the throttle. 

Mezzanine said:

Is there any other reason for putting the throttle upstream of the IC? Sorry I missed that detail in the sketch...Adding the IC after the throttle will do some really interesting things to your throttle response, and I suspect few of them will be positive. 

I love solving problems myself as much as the next person, but this is a place where I would have a hard time believing that I could be smarter or come up with a better solution than the 99.9% of tuners and manufacturers out there that put the IC upstream of the throttle. 

Regarding the IC placement and throttle response, I can't see any harm.  The ATW cores flow very well and offer virtually no restriction.  And if you are thinking about the volume of the plenum (of which the IC would be a part,) it's just volume, and it has to be charged back up every time you roll back into the throttle regardless of where the volume is.  So, you either do it with charge tubes or you do it without.  My idea is without.  With or without the volume of some charge tubes really won't make much difference in turbo response because the volume is small and the turbo moves a lot of air.  

99.9% of tuners and manufacturers don't have the packaging freedom that I am willing to give myself.  They have to think about hood slope, hood height, forward visibility, safety for the pedestrians that occasionally get scooped off the road and sent over the hood, etc.  I am willing to sacrifice the packaging concerns and build around them to an extent.  

You can flow more "cool" air through a TB than hot air is probably why the TB is down stream from the IC....with water/meth injection will you even need an intercooler.....

TurboFource said:

You can flow more "cool" air through a TB than hot air is probably why the TB is down stream from the IC....with water/meth injection will you even need an intercooler.....

TB size should not be considered a factor here relative to air temperature and density. 

I certainly will need an intercooler.  I am not running the engine on methanol.  I am running it on gasoline and adding methanol to overcome limitations in cylinder head design.  

Please share your thoughts regarding intercooling, related to the following points:

1) I built two FI X1/9s in my time at MWB.  One was the supercharged green K20 shown above, and the other was the one shown here: 

The K20 car used an ATW setup with a front mounted heat exchanger, whereas this turbo car used a conventional ATA intercooler installed just ahead of the engine with a slim line radiator fan installed on the core to keep it cool.  The intercooler was in the same location in both cases regardless of the other differences in design.  

2) As I see it, the location shown above or the space behind the driver on the engine bay side of the firewall are the only choices for the intercooler core.  Above the transmission might be appealing for an ATW unit because the charge tubes could be very short, but that location makes my aesthetic eye twitch.  Aesthetics might play a larger role for me than they should, but I like to make things look uncluttered and also minimize things being in the way of other things at maintenance time.  If I am not going over the top of the engine, I would like to tuck the intercooler and have as tidy an engine bay as I can get.  

3) ATW intercoolers are known for their thermal and airflow efficiency, but going ATW adds a lot of weight and complexity to the car, with a whole other fluid system (tank, pump, lines, electrics, and control over the pump.)  I also wonder about latency in the system and whether that works for or against me or both depending on situation.  I also would NOT be taking advantage of some of the neat options that open up with an ATW system such as ice boxes, using an AC system to chill the water, etc.  This isn't a drag car.  

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The part of me that likes simple things would like to do what is shown above, but with a duct to the front of the core that draws air from under the car to help provide fresh air to the intercooler core before the air is drawn through the core by a good slim line fan.  As on the car above, the fan would be actuated by a 1psi pressure switch.  Unlike on the car above, the fan would be powered by a circuit that counted off a certain amount of time, let's say one minute, after the last time boost was detected before shutting off the fan.  All of this could also be done with the intercooler on the driver side of the cavity instead of the passenger side.  Charge tubes would be only a little bit longer (if any,) and the spark plug side of the engine would be kept clearer to make maintenance easier.  

The duct design wouldn't have to be ultra efficient as long as it flowed air well enough not to become a restriction to the fan; the fan is what would drive air flow across the core.  I am imagining an aluminum duct that could be welded directly to the intercooler with the whole assembly slotting in to the cavity in a similar way to how the original gas tank did.  The X's side ducts are in the wrong position to help, so I'm not mentioning them (<--- except there.)  

The way I see it is that the ATA idea should work about as well as an ATW could without the extra complication, but I would like to hear other opinions.  

I always believe "ASAP" as simple as possible, is always the correct answer.

I'm looking at picking up one of these locally and after looking into the dimensions the first swap that came to mind after the Kswap was the 07k, but you mentioned that you weren't considering it. May I ask your thought process on that? 

Thank you for this thread!