As far as I know, performance upgrades for these cars are limited and the results of making special headers, head porting, compression increases and induction modifications, etc., would be marginal, at best. In addition, they would be expensive. The car is heavy and lumbering, and could stand a substantial improvement in the chassis/suspension/brake area. Further, I'm not sure the 3 speed transmission would be up to the task of a quantum increase in HP. If keeping it "stock" is not an issue, the 4.5L engine is rather large in size and I'm sure the engine compartment would handle a modern day firebreather, quite nicely; which would also give you some better transmission options -- with the added bonus of better gas mileage when you don't have your foot in it! Crate motors, from various manufacturers, are a lot less expensive than anything MB has to offer, you can be sure of it, and the performance increase would satisfy the most demanding desire for speed. At first glance, grafting in an engine does not seem to be that big of a deal on this car -- though such action may be seen as a sacrilege by some. The bottom line: it's only a matter of money.

I've pondered the same ideas myself, not being as impressed as many by the "superior German engineering" mantra, but have opted to keep my car original and stock. There is something very endearing and classic about this car, the older it gets. I have several other 'toys' which have undergone the "treatment," and allow me to satiate my wreckless moments.

Cheers!

 

There are dozens of things you can do to a 450 Sl,and the chassis is one area where fou don't need worry too much.Despite the comments about" heavy and lumbering" ,once you are making real horsepower the car will feel light and nimble.
To get power quickly,import a Euro 560 SEl engine and bolt that in.....or find a M-119 engine (plus donor car) .
Or do this....A 350SL with a Chevy in it.

It was imported into Australia by a Friend of mine.Apparently this conversion was done decades ago ,and cost the owner a small fortune because of the hassles ,especially the sump location of the chev.
Or this,My favorite. A genuine AMG 6.3 conversion....

 

The question posed, as I understood it, was what could be done to improve power/performance of the 4.5l engine he has in his car. If you know of dozens of things to do to improve this engine, please let us in on it. I, for one, would like to know and I'm sure many on this forum woud share this interest.

The possibilities with engine conversions are limitless, be it from the MB line, or from other sources. The "other" sources being more economically feasible, in my opinion, offering a greater range of options in terms of performance products at substantially lower costs. And let's not forget about transmission options, and so on.

 

I think that going with a freer-flowing exhaust system is a very good start. An engine that breathes better will perform better. It's also relatively inexpensive to do.

I would stay away from turbos unless you know EXACTLY what you're doing. Turbos present a whole set of problems with complexity and especially heat. The W107 family already has issues with underhood temperatures, so, unless there is some HD intercooling involved, I would think turbo(s) would do a lot more harm than good.

Another matter are superchargers. I've seen numerous fairly succesful installations of those on M117s. The heat is less of an issue with supers, but I would make real sure the engine itself is healthy enough to accept a blower. Depending on how much boost you run, you might need to lower the compression ratio, you also might need to play with cams.

In short, I'd start with the exhaust and go from there.

 

To your knowledge, is anyone offering headers or performance exhaust systems for this engine/car? I've searched the web, to no avail, looking for these particular items. I can't recall where I read about modifying Ford headers to fit, and can't say which Ford engine either, 302in/5.0L/5.8L or the 4.6L.

 

Changing the exhaust is going to be one of my first changes, I will most likely change it over to dual exhaust and scrap the cat. If I did pursue turbocharging I would definately throw a large intercooler in with it but I think I will have problems with gettin custom headers. I dont think I wanna shell out for a crate motor and new tranny unless I blow this one but if that did happen it would not be for quite a while until I finish school. A supercharger would be interesting I have thought about it but I already have a car with a supercharger (buick riviera)and I want more top end and I dont feel like losing anymore fuel economy.

Has anyone ever put high compression pistons on one of these or any similar models, I don't have any knowledge of the gains associated with this upgrade.

 

mercmad6.3 do u have any links on that 6.3 AMG? i wouldnt mind seeing some more pics of that myself or some specs.

 

Hot Rod MB

This is somewhat on the same line of thinking as myself. Short story is I am a Hot rodder under the skin. I want a light car with lots of low end power and really good handling. Maybe even drag race it. That said I don't need an old ford body and I think Mercedes has pretty good handling. My buddy has offered me his rusted old 76 SEL saloon 4.5 litre to chop up. So far I see the front and rear ends as a good start. The rest of the drive train might not fill the bill but I am not throwing it out yet. I need a good shop manual or some source for specs; like gear ratios, rear end ratio, steering ratio, etc. I know this is a wild project but I have a small budget at the moment and I need to get into a car again for the fun of build ing it. I am wondering if the fuel injection on this engine is the best way to go for low end power. Any ideas will be much appreciated.

Steveo

 

I have a german version 1977 350slc with the 4.5L in it i have had the exaust replaced to the headers. It has been replaced with a dual 2in through a magnaflow and it sounds great. later i removed the old air intake filter housing because if you notice how hot it gets when you have been driving around. I put in a holly freeflow which fits rather nicely in mine. I removed the blanket from the front of the car past the air filter going along the naturle body lines. Honesty I have also put alot of thought into turbos but a INTERCOOLED cintrifical super charger is porbably your best option because of heating isseus. my thought is it would fit nicely where the a/c is or isn't, but be carefull with hood crealence. I love my car and the engine feels so much happyer now. I don't know exactly how much more power i'm getting out of it but i can drift in it. You'll notice that the top end is alot higher, but if you want a good take off i suggest hold the brake and give just alittle gas but don't hold it past 13 on the tach. Just a suggestion I tried zmax and it helped clean it out and restored some power.

 

Look like everybody has reached the same conclusion as I have but applying some lateral thinking there are some posibilities as follows:
1. Exhaust: I have seen the headers that are used by AMG and they are split as pairs on each side. Two pipes coming from each bank and then you go dual to the back of the car. An earlier post is nearly there just needs the headers.
2. Air intake: All modern cars have switched to cold air intakes which makes sense, whereas ours still breathe the hot air under the hood.
These are the simple ones
Now the more difficult:
1. A new brain such as a Haltech unit or for the DYI people the Megasquirt. These both are fully programable using a laptop whilst you are a passenger or on a Dyno. Both have O2 sensors which gives the feeback to make sure the fuel / air ratio is right. Max power for your litre.
2. Manual Transmission Conversion: There is a site here in Australia which is by a company that produces manual tranny conversion kits for the M100 engine - 6.3L & 6.9L Check the following link: www.big-toys.net
I have a 74 450SLC and I am looking at doing all of the above as I believe that it is achievable.
Other things like increased compression, cams etc are all too hard and generally should only be sought from AMG. I have tried this avenue but without success so far..........
Hope it helps!!

 

Contrary to what a lot people say,you can get all sorts of power rom the 450 engine...in the US you have the option of ringing Isky himself ,and I'll bet his son Ron has already ground a profile or two for mecedes Engines in the past.
If you want extra horses,PUT THE COLD AIR TUBE BACK ON!!! Mercedes have had this idea on their cars since 1959 with good reason! it WORKS!.
Any 6.9 owner wil tell that just installing a W126 560 air cleaner with the twin snorkles gives more power that you can actually feel.
make sure the engine is a high compression engine and not a low compression item from a W116 or even a W109.....
The intake is pretty small for a V8 and I think if twin throttle bodies were installed on the intake manifold a lot more horsepower would be unleashed.


The Kjet Injection air meter body could be swapped for a 560 intake,the fuel distributors are the same but the plate area is larger.
I still like the idea of fitting a larger engine and I have been assisting a guy to install a 6.9 into a W107...not at all easy actaully.AMG made a special crossmember,shifted the location of the oil filter ( 6.9's are different to 6.3's ) and made a diffrent hood to clear the engine.They even made a new injection system for the three cars they built with the 6.9 ( bored to 7.2....} )
Heres one with a 6.3 ...

We have been discussing this swap for some time now here:
http://www.m-100.cc/forum/topic.asp?TOPIC_ID=1162
The guy I'm helping has spoken with the man at AMG ( Germany) who did all the work onthe W107 engine swaps ,so we are on the right track so far...
AMG still have lots of parts in stock,but you need to able to Quote part numbers befoe you will get a response.

.
The exhuast on the right can be made by any competant muffler shop...

 

Look like everybody has reached the same conclusion as I have but applying some lateral thinking there are some posibilities as follows:
1. Exhaust: I have seen the headers that are used by AMG and they are split as pairs on each side. Two pipes coming from each bank and then you go dual to the back of the car. An earlier post is nearly there just needs the headers.
2. Air intake: All modern cars have switched to cold air intakes which makes sense, whereas ours still breathe the hot air under the hood.
These are the simple ones
Now the more difficult:
1. A new brain such as a Haltech unit or for the DYI people the Megasquirt. These both are fully programable using a laptop whilst you are a passenger or on a Dyno. Both have O2 sensors which gives the feeback to make sure the fuel / air ratio is right. Max power for your litre.
2. Manual Transmission Conversion: There is a site here in Australia which is by a company that produces manual tranny conversion kits for the M100 engine - 6.3L & 6.9L Check the following link: www.big-toys.net
I have a 74 450SLC and I am looking at doing all of the above as I believe that it is achievable.
Other things like increased compression, cams etc are all too hard and generally should only be sought from AMG. I have tried this avenue but without success so far..........
Hope it helps!!

Couple of thoughts:
Easy Options 1 & 2: Would both give a bigger benifit if you enlarge and polish the inlet and exhaust ports on the headers.
Difficult option 1: I believe the '74 has the electronic fuel injection which was dropped due to lack of emission control. What it does do well is dump loads of fuel into the engine especially at full throttle. A modern engine management system may provide smoother running, as it will control fuel timing and quantity more accurately, but it may not give more top end power.
Difficult option 2: I doubt the M100 tranny will bolt onto the 117 engine without a lot of adapting/cost/pain.

How much time and money are you looking to invest in the possible benefits. You could import a Euro spec model and get 40 extra bhp straight away.

 

[ A new brain such as a Haltech unit or for the DYI people the Megasquirt. These both are fully programable using a laptop whilst you are a passenger or on a Dyno. Both have O2 sensors which gives the feeback to make sure the fuel / air ratio is right. Max power for your litre.]


I'm ordering the "Megasquirt II" unit and other parts today from 'DIY Autotune' to install on my 78 450 SEL in place of the Bosch mechanical fuel injection. Others at the MS forum have reportedl horsepower gains as well as substantial fuel economy increses doing this swap.

I also want to do the header swap and I think that ordering some generic Ford 302 headers (around $140) should be useful if I make new flanges and perform a modest amount of cutting, bending and welding.

Does anyone know which 4 speed automatics fit in place of the stock 3 speed slushbox?

 

Don't worry about swapping the slushie. Nothing else fits straight on. And the 3 speed was so good MB left it on their rally and racing SLC's.

 

[ A new brain such as a Haltech unit or for the DYI people the Megasquirt. These both are fully programable using a laptop whilst you are a passenger or on a Dyno. Both have O2 sensors which gives the feeback to make sure the fuel / air ratio is right. Max power for your litre.]


I'm ordering the "Megasquirt II" unit and other parts today from 'DIY Autotune' to install on my 78 450 SEL in place of the Bosch mechanical fuel injection. Others at the MS forum have reportedl horsepower gains as well as substantial fuel economy increses doing this swap.

The megasquirt requires electronic injectors which means you will have to bore out the injector ports on the heads to fit them.Unless you remove ther intake mainfolds and jam rags down the ports ,you are going to get lots of Swarf in the engine. not a good thing to have happen.

I also want to do the header swap and I think that ordering some generic Ford 302 headers (around $140) should be useful if I make new flanges and perform a modest amount of cutting, bending and welding.

I have seen this done before,on a M-100 though.it involves cutting the ford flanges off and rotating them to fit the Mercedes head bolts. the collector was removed and the pipes shortened to fit the manifolds( headers) into the car,a W113 .(!!) The pipe spacing is similar to the mercedes ons so they almost fit .

Does anyone know which 4 speed automatics fit in place of the stock 3 speed slushbox?

They all fit.the only difference is the shift gates in the console.The top three ratios are the same,but the extra gear is a low first.In normal operation the trans moves off in second,unless you plant the loud pedal ,then it starts in first in the kickdown mode.If you want to use a later 4 speed from a w126 you could use the shift gate with the "B" position which enables first to be selected for those smokey starts .
Convertors etc are all the same. be prepared for a bit of drive shaft swapping about though,some cars came with longer than normal shafts which are too long to fit the 722.313 (etc) trans .

 

Ford Headers

I have seen small block headers in various configurations at very low prices on Ebay-some for practically just the shipping plus a few bucks. . Might be worth a few bucks to buy some inexpensive used 302 headers to see how much modification it would take to make them fit.

 

Well a year has passed since my last post here and I have finally found that there IS a V8 in my 450slc. My MEgaSquirt computer is now installed and working. I was having a lot of trouble tuning the mMEgaSquirt and getting the Mercedes to run smooth so I took about a six month hiatus and recently just started this project back up. I ended up purchasing an Inovative LC-1 wideband O2 sensor and installing it in place of the stock Mercedes sensor (screwed right in). This with a new version of the MegaSquirt firmware has worked wonders on my old 450slc!!

The new version of megasquirt firmware has an autotune function that updates the VE table in flash as you drive so the system now in essence tunes itself. Man what a difference!!! Not only does the 450 accelerate much faster, drive smoother but it finally idles smooth as silk. I pinched off the idle air port down to almost nothing and she idles very smooth all the way to 450rpm!

It no longer chokes when coming to a stop and I dare say it is getting to be darn near as fast as my 2003 Maxima (OK maybe I am a little enthusiastic.)

My biggest performance problem is now the automatic transmission. It still shifts smooth but the low shift points limits any really aggressive acceleration. Now from 50mph to 100mph (ok 85mph with the needle starting to bow) is without a doubt as fast as my maxima which also has great power in this band. I can imagine that a stick shift with this configuration would be quite a car.

I still have a fair bit of clean up work to do. I have a GM IAC (Idle air control valve) installed but not wired up yet. My TPS (throttle position sensor) that I rigged up as an extension off of the first throttle linkage with a short piece of rubber tubing is flaking on me and is currently disabled. The stock TPS is just a switch that makes contact at WOT (wide open throttle). I would like to find a variable resistor TPS that would replace the stock one but it is a hard part to get too without taking off the intake manifold. A variable resistor TPS would allow me to tune the AE (acceleration enrichment) table for even better acceleration. I also need to do some plumbing to fit an air filter. The stock air filter can definitely won't work.

I will try to make a list of what I have in her so far:
1) MegaSquirt V2 - board rev 3.
2) MegaStim (Stimulator board for building and testing the megasquirt)
3) MegaSquirt wiring harness / cable (I would definitely do the relay board next time and I might switch to the relay board)
4) Inovative LC-1 wideband O2 sensor.
5) 3 sets of fuel rails. The first was copper tubing and sucked. The second was made out of aluminum fuel rail stock and I didn't have the injector bungs drilled perfectly causing fuel leaks, hydrolock (petrol lock might be a better way to put it) and vacuum leaks between the injectors and the heads. The third was out of the same stock but measured much more accurately. OK, I actually had 4 sets of fuel rails as I made a fuel rail out of hard maple to perfect the spacing before ruining more aluminium stock.
6) An inexpensive Ebay adjustable fuel pressure regulator with pressure gauge.
7) about $100 worth of various brass fittings and hydraulic hose before I got the fuel hoses satisfactory.
8) GM IAC valve.
9) 24 Ebay fuel injectors from for mustangs (5.0 and 4.6) I turned the barrel of these down a few thousands to fit them the stock injector holes in the heads.
10) Probabally 50 injector o-rings to get the injectors to seal to the fuel rail properly. (The first aluminium rails I also drilled to deep for the o-rings to bottem out and seal as well as not making a smooth enough radius at the opening so they chewed up o-rings on injector insertion). (I found that a 1/4" woodworking roundover bit chucked in the drillpress makes perfectly radiused "trumpets" for the injector holes in the fuel rail)
11) GM IAT sensor (Intake air tempature) and connector.
12) 8 Fuel injector connectors from a mustang.
13) Laptop for tuning
14) Targa universal AC/DC adapter for running the laptop off of the 12VDC cigarette lighter socket.
15) Extra fuel pump relay off of ebay to replace the one I blew up.
16) Soldering iron
17) Solder, wire, heat shrink tubing etc.
18) 2 12vdc relays. (Cheapies off of ebay have been working great)
19) Fuses and inline fuse holders (I would highly reccomend the megasquirt relay board instead)
20) Multimeter
21) Oscillascope (helped in diagnosing the loose connector that was keeping one of the banks of 4 injectors from firing but not necessary).
22) Battery charger.

The hardest part was probablly getting the initial VE table to get the 450 to start and run so here is a headstart for everyone else. Table at about 40psi fuel pressure and stock ford mustang (19 Lb if I recall correctly) injectors in two alternately firing banks.
EVEME 1.0
UserRev: 1.00
UserComment:
Date: 03-15-2007
Time: 21:04
Page 0
VE Table RPM Range [12]
[ 0] = 5
[ 1] = 8
[ 2] = 11
[ 3] = 14
[ 4] = 20
[ 5] = 26
[ 6] = 31
[ 7] = 37
[ 8] = 43
[ 9] = 49
[ 10] = 54
[ 11] = 60
VE Table Load Range (MAP) [12]
[ 0] = 30
[ 1] = 35
[ 2] = 45
[ 3] = 50
[ 4] = 55
[ 5] = 60
[ 6] = 70
[ 7] = 75
[ 8] = 80
[ 9] = 85
[ 10] = 95
[ 11] = 100
VE Table [ 12][ 12]
[ 0] [ 1] [ 2] [ 3] [ 4] [ 5] [ 6] [ 7] [ 8] [ 9] [ 10] [ 11]
[ 0] = 26 26 29 34 40 46 50 55 58 61 61 60
[ 1] = 29 29 32 38 46 53 56 60 63 66 65 62
[ 2] = 38 42 39 44 53 61 65 67 69 73 71 66
[ 3] = 43 44 43 45 54 63 66 69 71 75 73 67
[ 4] = 48 46 48 50 58 65 69 71 73 77 75 69
[ 5] = 52 51 52 55 62 67 71 73 75 79 77 71
[ 6] = 57 59 61 65 69 72 76 78 81 85 85 80
[ 7] = 61 62 65 69 72 75 79 82 85 89 88 84
[ 8] = 65 66 69 73 76 78 82 86 90 93 92 88
[ 9] = 68 70 73 78 81 83 86 90 94 98 97 93
[ 10] = 72 77 82 87 90 93 95 100 105 109 108 103
[ 11] = 74 81 86 91 95 97 100 105 111 114 113 108

 

Good GOD! I wonder if I could rig something like this up for my 108's 4.5... just about the same engine, isn't it?

 

It was a lot of work and ended up being a little more than a weekend project but it was definitely worth it!!!! I still have a lot of clean up work to do now that my 450slc is running well.

I disagree with the statement that the CIS injection system is good at dumping in a lot of fuel and making good power at high RPM. This couldn't be further than the truth.

In Naturally Aspirated engines powered by octane, maximum power is frequently reached at AFRs ranging from 12.5 - 13.3:1 or λ of 0.85 - 0.90. Richer mixtures can result in lower power due to slower burn speeds.

My 450 has hugh power gains at high RPM by being fed a proper air and fuel mixture. The CIS injection system doesn't come close to maintaining a proper AFR hence lousy gas mileage and lousy power.

 

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

 

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.

 

replacing the manifolds with modified small block Ford headers

Is there a particular brand or something to look for?

 

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?

 

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.

 

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.

 

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.