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Intercooling Bosch injected, non-chargecooled engine

35K views 133 replies 22 participants last post by  MRDANGERUS 
#1 ·
I decided that while I had my car apart chasing oil leaks, I would take the time to intercool the engine as well. The only viable option is water to air, as there is just no cool airflow near the engine to use. I don't want more power, just reliable / consistent power.

I started with a 24"x6"x2" heat exchanger stacked in front of the A/C condenser. I relocated the oil cooler a little further forward and standing straight up, then put the heat exchanger at an angle against the condenser. It is a tight fit, but it all goes in nicely. The water lines both exit the passenger side of the car. Technically I am mounting the heat exchanger upside down, so the "drain" is now a bleed vent. I created a remote bleed valve that hangs down below so that the front of the system can easily be bled.

I put the bosch water pump in the cavity in front of the passenger side front wheel. It pushes the water through the heat exchanger.

I ran two 1" aluminum pipes down the frame under the car. They tuck in nicely on either side of the frame between the frame and the body.

In the engine compartment there is alot going on. I will let a photo do the talking. I did a coolant bottle to act as a reservoir, plus a bleed line off the highest point into the coolant bottle to help self bleed as much as possible.

I sourced the parts from all over, if you have a specific question on source, just let me know. I also repainted my red stuff with VHT wrinkle red paint, then a 2 part clear coat.

I haven't driven the car yet, wiring in a old plxdevices wideband O2 sensor controller. It has a cool option of outputting a modified narrow band signal. Goal is to input from the wideband, modify the signal, output to the bosch ecu system. I can output that the car is running a touch lean, to trick the computer to give more gas.

The wideband actually has 2 outputs. Someone gave me the idea of connecting a relay to the full throttle switch. Instead of going to a fixed duty cycle for the frequency valve at full throttle, the relay can switch the O2 sensor output to the bosch computer to the modified signal and run closed loop full throttle with a modified signal to richen the mixture to my liking. Right now, I will just watch the meter to see what is going on, but it is nice to have a tuning option that doesn't cost $600 like the digital WUR.
 

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#3 ·
Holy jeezus creezus, that is beautiful. Your engine bay is awesome--once my engine-out project gets started, this will definitely be something to aim for. Intercooling this Bosch-injected car is exciting stuff! Outstanding!:drool:

Cheers,

Scott
 
#4 ·
How are you interfacing to the Bosch ECU? Are you using the wide band sensor to effectively ground pin 11 for more gas? Not sure that works across the RPM spectrum (from my armchair)?

MRDANGERUS will probably weigh in here as he definitely likes to tinker with the Bosch CIS stuff. Nice engine compartment work for sure!
 
#6 · (Edited)
ExTrax:

BRAVO!
Mater artium necessitas!

You did your homework well! Interesting use of the PLX device.

You know...
there is a 100 ways to skin the cat.

Shoot for: Cruise 14.5 -15 afr,
Drops into 12's @ boost onset,
11.8 afr between 4000 to 5200 and
12-12.2 at max revs...

Cooler charge = higher VE and you can run full 10 psig (remove the wastegate spacer ring).
AEM 30-4350 controller may be a nice add on.
You may add a turbo blanket at the turbine housing and another one over the adapter to minimize the radiant heat.
 
#7 ·
I have not finalized my ECU tuning plans yet. I am going to first see how it all reacts with the stock boost and stock tuning.

I have an issue with my CIS, the frequency valve duration hovers around 70% at idle currently with the o2 sensor disconnected. This tells me I have a messed up sensor somewhere, as the ECM should resort to 50% assuming all else is inline. During the investigation of this, I realize there is no WOT switch. I guess I will have to use my O2 emulation trick at above 29 degrees throttle opening.

I am planning to add a good bit of heat shielding stick on blanket on the bottom of the intercooler, sleeve the water lines, and wrap the turbo exit lines as well.
 
#9 ·
Wow, excellent work!

Interesting ideas on the wideband output, I'll have to check that out for my other project as I've got a PLX sitting in the toolbox. I usually manually input the WOT cells around 11.8 on pump gas and just rely on closed loop stoich for cruising and conditions under 2 psi boost. It's nice to see this applied to the Bosch system.
 
#11 ·
True. PLX recommended 24" I showed them how far away the current Lotus placement of the O2 sensor, they didn't like that

I told them 24" away was below the CAT, and they said that would be fine, so that is where mine is. Works fine.

Mounted at the recommended angle, right before the muffler.


I left my original narrow band O2 in the stock location, rather than feeding the narrow band data to the ECU from the PLX sensor module.
 
#14 ·

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#15 ·
No, unfortunately I burned a valve shortly after I did all this work. Not related to the intercooler, some welding that was done on the head before I acquired the project failed and put some aluminum on the valve seat, leaving the valve not completely sealing, and burned right through. I pulled the engine, tore it down, and currently have parts out at various shops getting refurbished. I should be back in business December or January.
 
#18 ·
What would be extremely helpful in pure 20/20 hindsight: some sort of detailed "How to" with specs, suppliers, accurate measurements so these astonishingly cool results might be, if not standardized and replicated, at least emulated in some way. I'm not sure, but on TLF the Esprit section has a sub-forum for blogs where members post often detailed processes so perhaps one of our members is on there?

Another forum I enjoy perusing is the VW Vortex's Bosch CIS subforum, where some members have stuck with CIS and added turbos and intercoolers / after coolers and achieved (sometimes questionable) results. But that is off-topic-ish.

Gorgeous engine bay shots, Loren. For me, the engines in this thread are as much automotive art as they are inspiration.
 
#19 ·
Wow Loren, love the progression from your initial installation to your latter. That looks extremely well done. I assume that is a carbon wrap over the panels that cover the gas tank tops? How has it held up in that high heat area?

Everytime I look at the plenum I want to get rid of it and do a proper plenum. There is plenty of room to do it.

As I put my car back together, I will give some better data in a build thread as to where I got parts, what it took, and how I did it. It will be a nice winter project.
 
#20 ·
Yep, a big part of the C/C system is that stupid, heavy, restrictive, box shaped plenum. A pretty simple foam positive mold and a little carbon fiber not only makes the volume larger and the shape more efficient, but weighs 1/10 of the original. Taking stress off the intake manifold and increasing plenum diameter improves flow and efficiently.
 

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#23 ·
Well my cylinder head just got back from the head shop, and my motor is almost back together. Just got my valves dialed in today, so I am going to button the rest of the motor up this week and hope to drop it back in this weekend. I have had a couple of work related delays that have kept me away from the project, and now I have a major motivation to get it done.

I sold my house, and I am moving at the end of this month. If I don't get this car running in the next couple of weeks I will be towing it to my new home, and pushing into the garage. That is no way for an Esprit to enter a new neighborhood.

One way or another, I need to finish it in the next few weeks.

I will keep you guys posted.
 
#24 ·
Oh yeah, and the show House Hunters filmed at my house a few weeks back. There may be a (dirty) Esprit in the show if they filmed the garage at all. I guess we will see in the coming months.
 
#27 ·
Nicely done!
I like how you relocated the oil filler cap too as the original cap on the Bosch cars is usually where the intercooler now sits.

Do you have any threads or website detailing this retrofit of a factory intercooler to a Bosch injected Esprit? :bow:

Roy
 
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