Performance Upgrades

[mundayc]

Re COLD AIR INDUCTION: here is a guy in Oz who designed a good system!

Improvements to M116 in early 107 (true cold air intake) - ShopForum

[hbar]

A relatively easy performance upgrade that is nearly always a significant benefit on cars equipped with them is to swap out the mechanical cooling fan for an electric one which reduces engine drag. This typically gains 10 or so horsepower in the upper rpm range (just where it's needed).

Tomorrow morning at 8AM I'm officially starting my 450SEL "performance upgrade" and am going to put to the test some of the suggestions on this thread (and some other ideas). I will be:

- replacing the Bosch mechanical fuel injection for new efi components and MegaSquirtII programmable controller and wideband O2 sensor
- removing the distributor and installing an EDIS with 36-1 crank trigger
- replacing the manifolds with modified small block Ford headers
- enlarging the aperature to the air filter and routing to cooler air from under the front bumper
- removing the cats and replacing with an x-pipe and run 2 1/2" exhaust everywhere
- replacing the mechanical cooling fan with an electric fan
- disconnecting and removing the AC (it doesn't hold a charge anyway)
- replacing the stock 14" aluminum wheels with Wolfrace 15" wheels and better tires

I already have on hand all of the above items, and hopefully most of the peripheral stuff I need so it's just a matter of banging out this project in my small amount of free time over the next few weeks.

And because I like to think ahead (admittedly this is a future upgrade when I have a bit more money to play with) installing a supercharger at about 5 psi boost where the AC used to be is the next logical step.

[w116.org]

They should be some very interesting upgrades you will be performing which I and many others would be keen to know more about. Keep us posted and don't forget to take pictures!

Will you be swaping to the D-jet instead of the K-Jet?

Have you considered ways to get heat out of the engine bay together with getting cold air into the engine?

[oughtsix]

Hbar,

I got your pm and I thought it might be better to answer your questions here incase someone else might find the information useful or be able to suggest a better approach.

I used the stock intake manifold and heads from my 80 450slc in my megaproject. The injector holes are in the heads not in the intake so going to a pre 74 efi setup would have meant swapping the heads. The stock mercedes CIS injectors are long and narrow and sit in white plastic injector insulators that together make a profile very simular to an electronic injector. My insulators were as brittle as glass from heat and age. I purchased a new set of insulators from performance products. The ford injectors (bosch) will seat in the injector insulators but they end up protruding out of the head quite far making it dificult to form a good seal. The injected fuel then also has to flow the length of the insulator to make it to the intake valve which turns the fuel spray back into a fuel drizzle that we are trying to get away from. I WOULD NOT RECCOMEND USING THE MERCEDES FUEL INJECTOR INSULATORS.

I also purchased a set of the black rubber injector seats for pre 74 efi injectors and found these to not work well either.

The second diameter on the ford injectors is the one that is a bit to large to seat properly. I ended up turning the injectors in my old atlas lathe down a few throusands at this location and they seat perfectly into the unmodified heads. You could probabally ream the heads out but I don't see how to do this without removing them first. The injectors are an almost solid chunk of steel and have more than plenty of material to remove. Chucking them in the lathe the hardest part.

Some parts you might want to add to your buy list are:
1) Intake manifold gaskets
2) 8 of the black rubber hoses that seal the upper intake to the lower intake. These were very dry and cracking on my engine.
3) Gaskets for the water pump.

All of these were realitively inexpensive from performance products.

I used the stock throttle body from my 4.5 and it works well except for the TPS (Throttle Position Sensor). The stock TPS is just two switches, one that closes at idle and one the closes at WOT (Wide Open Throttle). This will not work with MegaSquirt and I have not found a replacement yet. My car still runs so much better on map and tempature without a functioning tps with megasquirt than it ever did with CIS.

On my 4.5 there is a rubber reducer between the ~3" diameter throttle body and the ~4" diameter CIS mechanicals. I found a piece of 4" plastic conduit (just grey 4" pvc pipe) fits into this rubber reducer perfectly. I used a piece of pvc about 4" long and drilled a 1" hole halfway up. I glued a piece of 3/4" pvc into this 1" hole and then tapped the inside of the 3/4" pvc with a 1/2" npt (national pipe thread) tap which holds the gm IAT (Intake Air Tempature) sensor perfectly. I haven't yet plumbed this to a air filter. My thoughts on boost is a M90 supercharger off a GM 3.8.

As you are probabally aware from the megaboards you should keep your ignition and fuel injection projects seperate. I have looked at the Ford EDIS ignition system but the MSD 6a I have been running for several years is working very nicely. I originally tapped into the green sheilded wire between the distributor and the ignition module. WRONG!!!! This gave a very noisy signal to megasuuirt and did not run well at all. I then wired the megasquirt ignition sensor to the output of the ignition box where it goes to the coil. This has been working very well. My MSD ignition sensor is wired to the same spot with a spade terminal making it very easy to move the MSD sensor wire from this point to the Megasquirt spark signal by just moving the spade connector.

Another mistake I made was not buying the relay board. I will buy the relay board and rewire everything when I can come up with the cash. I thought I would make things easy on myself by using connectors when wiring the megasquirt. ANOTHER WRONG!!! I had more problems with the damn connectors that any other part of the wiring. If you are going to use the 37 pin cable with magasquirt instead of the relay board wire everything directly to the components (injectors, sensors etc.) and solder, do not put connectors in the middle of the wiring. By this I mean connectors other than the component connector itself.

I located my megasquirt in the footwell where the old ecu was. This made running the cable a real treat. On my 450slc there isn't a good place to drill through the firewall on the passenger side. There was an extra hole in the firewall above the steering column complete with sealed off gromet. So I pulled the megasquirt cable up the footwell through the dash and out the hole above the steering column. This worked nicely on my setup and positioned the cable for easy routing in the engine bay. Again I will use this same route when I swap to the relay board I should have used in the first place.

If you would like to keep us posted on your progress I would be happy to tell you about my screwups to hopefully make things easier.

I am a visual C++ programmer by trade and an avid auto hobbiest and wood worker when I am not busy being a daddy. I built my first electronic kit over 30 years ago which was a tube radio from a surplused army electronics training course.

[oughtsix]

This is the stock I used to build my fuel rails out of:
eBay Express: Dash 6 Fuel Rail Extrusion custom fuelrail - Description
It took me two tries with this stock to get the fuel rails right. DO NOT DRILL A PILOT HOLE WITH A 1/8" BIT IN THIS STOCK!!! This is how I started and the aluminium is so soft the bit snapped off in the stock and it is impossible to get out causing the fuel injector bung hole to be slightly off and all sorts of vacuum seal and fuel sealing problems.

I used two 3/8" NPT to 6an elbows on two of the fuel rail ends and two 3/8" NPT to 6an Tee's on the other two ends of the fuel rail. Tapping all four ends of the fuel rails with a 3/8" npt tap. I used some 6an to barbed fittings from nappa as well as nappa hydraulic hose made for use with the barbed fittings. This has worked out very nice. The 6an plumbing is only good to 500hp or something as opposed to 8an 1200hp but I seem to be getting by OK.

I was woried about heat soak from the heads to the injectors as Mercedes obviously was also because they used the injector insulators. I have had absolutely no problems with heat soak or vapor lock in the injectors.

[hbar]

Originally Posted by w116.org

Will you be swaping to the D-jet instead of the K-Jet?

Have you considered ways to get heat out of the engine bay together with getting cold air into the engine?

Essentially the MegaSquirt replaces ALL of the stock Bosch components (either Kjet or Djet) with the exception of the intake manifold, which will then have to be slightly modified. "oughtsix" kept the stock Kjet manifold for his project and it looks like I will have to as well.

As far as underhood heat buildup, I'm not going to worry about it unless it becomes a problem, at which time I'll put some thought into it. I don't think it will be an issue as I only expect to see modest horsepower gains (perhaps 15 to 25HP from all the mods combined) I do plan to thermal wrap the headers, though.

[hbar]

Thanks for the great info, "oughtsix"!

I have access to a computerized machine shop at work as well as knowlegeable machinists there willing to help me (I'm not a machinist by any stretch) and I can easily turn down the injector barrels to make them fit into the stock holes in the heads. Good advice on the insulators.

I'm looking at ways of getting a later TPS to fit the stock throttle body, or failing that, replacing the entire throttle body witha later unit such as from a Ford 5.0 EFI and modifying it to fit the intake (not difficult) and then modifying the throttle linkage (somewhat more difficult).

I'm converting the fuel first and then getting that running to my satisfaction with the stock ignition before tackling the EDIS conversion.

I went ahead and bought the relay board along with the fully assembled and tested MSII. I also bought the additional wiring and connectors because I figured the less parts I had to cobble together myself the much greater chance I'd have a running engine with no significant troubles when I finished.

I'll probably end up buying that fuel rail stock shortly as soon as I finish sorting out the injector to head configuration.

Am taking pictures of disassembly now and will post (probably after this weekend) when I have something interesting actually put together.

[oughtsix]

I found some early pictures. If you have access to a machine shop turning down the injectors should be no problem. It would be nicer to open up the hole so you can change injectors anytime in the future.




You can see some slight jaw marks where I chucked the pintle of the injector in the lathe. As you can see I had to take very little off the injectors to make them fit. (The middle band of silver with the chatter marks is the only part that needs to be machined) I measureed the stock ford injectors at .941" and the ones I turned down at .910" - .925" (I blame the poor tolerence on my tools, it's a craftsman lathe. It couldn't have anything to do with my inexperence with machining 8-). The .925" injector fits in the head without a problem. Someone with a drillpress and a bit of injinuity could probabally do a better machining job than I did.

[oughtsix]

I really like the nappa hydraulic line for use as fuel line. Just push the line onto the barb and it is good for up to 200psi without any kind of crimp. It is very heavy but the 6an connectors make it easy to work with. When I went into nappa and asked for 6an connectors they didn't carry any. After a minute of talking with them they discovered I was talking about standard 45degree connectors or something and they have a very large selection.

You can see my grey pvc intake plenum in this picture and the white PVC holding the IAT (Intake air tempature) sensor.
At the top of the picture you can also see my IAC (idle air controll) motor in it's aluminium block. I just used a couple of 1/2" copper fittings and some hose to plumb the IAC to the idle intake ports on the intake manifold. The IAC is mounted to a piece of angled aluminium stock that is bolted to some retaining studs that previously held the CIS mechanicals. To the left of the IAC you can see a variable resistor. This is my new TPS (throttle position sensor). I plan on putting a small arm on this variable resistor and connect it to the throttle linkage. Pretty much any variable resistor will work as a tps with megasquirt and the range of movement isn't even all that important since you can set idle and WOT positions very easily in megatune.

I had to put a 3/8" NPT elbow on both ends of the driver side rail before I could put the 3/8" - 6an "T" fitting on to clear the valve covers with the fuel line. The two fuel rails are plumbed in parallel. From the stock fuel pump to a "T" fitting to each of the fuel rails. Then from each of the fuel rails through the "T" fitting shown to the Fuel pressure regulator. This is supposed to keep a constant flow of fuel over all the injectors and keep the fuel from heating up in the rails. The fuel pressure regulator is plumbed to the stock mercedes fuel return line.

I am kind of proud of my fuel rail retainers.

This is my first attempt at an aluminium fuel rail. I broke an 1/8" bit off in the rail while drilling a pilot hole. The subsequent hole was off just enough to cause vacuum leaks and fuel leaks. I also drilled the fuel injector pockets too deep on this rail. You want the top O-ring to seal against the top of the fuel injector bung hole (pocket) as well as the sides of the pocket. My injectors did seal on the top of this rail until I put the fuel injector electrical connectors on the injectors. This made the pockets just a little too deep. Keep in mind the width of the fuel rail vs. the 45degree fuel injector electrical connector with a female socket on it when deciding on the depth of the fuel injector pockets. The pockets don't need to be as deep as they seem like they should be.

I started the injector pockets with a 3/8" hole all the way through to the fuel passage. I then opened this up with a 1/2" bit about 3/8" down. I then opened this up with a .540" reamer I got off of ebay. An adjustable reamer won't work because it won't fit through the 3/8" hole. On this rail I used a countersink bit to make the entry chamfer. On my current rails I used a 1/4" round over woodworking router bit to make the entry chamfer. The router bit worked much better than the countersink and made a perfect trumpet shape. I cleaned the pockets up with a dremmel fitted with a buffing pad and some rouge polishing compound. The pockets have to be smooth or you will split an o-ring when inserting the injectors.

After messing around with some springs and such I decided simple is best. These retainers bolt onto the intake where the old fuel injector clips used too. You can actually cut the tip off of the original fuel injector retainers and use them on the electronic injectors but this doesn't do any thing to retain the fuel rail on the injectors. You can get fuel injectors with barbed fittings or screw on fittings and make your fuel rail out of fuel hose but these types of injectors are very hard to find.




Yes, if you look real close at my retainers you can see numbers and graduation lines on them. If you look even closer you can probabally see harbor freight stamped on them somewhere. At $1.49 the cheap plastic harbor freight machinests squares make perfect stock for 3 retainer clips each. I have 4 retainers for each fuel rail but as you can see in the top picture only two clips per rail works just fine and hasn't been a problem. I just need to bolt the remaining clips on.

[oughtsix]

Hbar,

What are you using for injectors? If you are using pulls from another car make sure you get new fuel injector hats and O-rings. You may want to get at least an extra set of each as they are pretty cheap and pretty easy to destroy by accident. The hats are very easy to crack when you put the new ones on the injectors. I found soaking the new hats in boiling water for a few minutes before you put them on your injectors helps them pop on a LOT EASIER. I went through several top O-rings before I got everything worked out with my fuel rails. The rounded openings didn't tear up the O-rings like the 45degree chamfered openings did.

The biggest problem I have with replacing the stock TPS is you have to take the whole intake maniffold off to get to the TPS. I read on the megaboards something about taking the throttle body into a parts store and trying TPS's from different engines on the throttle body to get one to fit. I should have done this back when I started. Oh yeah, there are a couple of vacuum lines for the CIS that go into the throttle body. I think I used one 1/4" vacuum plug and a couple of 1/8" vacuum plugs. These are easier to get to when you have the throttle body off but you can get to them with a pair of needle noses from the top if you know where they are. (I have a 1980 4.5 with extra emission equipment, your engine might be different)

I do have a ford throttle body with integrated TPS, IAC and MAF sensors but it didn't look close to fitting without a whole lot of elmers glue and bubble gum My gut feeling is the stock throttle body is plenty big enough at least until you get headers. BTW I am feeling the need to rush you through this install so you can engineer the headers for me

P.S. I am trying to show you what I did wrong in my install because I think this information is more valuable than what went right. I look forwards to seeing your approach to this install and learning from your ideas.

Best Reguards,
Mike.