4 barrel EFI idea - on an EFi 3.5 - Better or worse?

Lewis · Post by **Lewis** » Sun Apr 29, 2007 5:40 pm

Now, call me retro but I prefer the look of a four barrel to the swish but uninteresting standard Rover plenum.

As I'm now used to the joys of fuel injection, I was considering ways of getting the period look with the running benifits of EFi. Flicking through one of my 'build your own EFi' books I stumbled across an article on converting a Dodge Challenger B-block using such a system - however as I read into it it became clear that Pro-Jection was more of a standalone thing.

A bit like this:

As they found some problems with it, they modified the system by welding injector bosses onto the manifold (as it was a single plane Edelbrock, with runners that are in line with eachother) and converted to an aftermarket ECU, utilising the Holley as a throttle butterfly.

I was just wondering if anyone had tried something along these lines - using a 4 barrel manifold, getting the bosses fitted to it and using a plain Holley or Carter AFB to control airflow, with a Megasquirt system controlling the fuelling.

This allows the use of period air filters and so on (like the yummy Cobra ones

)

Do you think there could be an improvement over the standard system here? If there is that chance - I'll get to it and pick up the appropriate bits!

(Then I can report back when it transpires to be exactly the same

)

I just stumbled across this as well :

http://www.barrygrant.com/bgfuel/default.aspx?page=63

But I'm not sure how you'd control something like that with Megasquirt, or wether you even could.

This is what I'm talkin about:

As much as I'd love to go turbocharged, I swear there just won't be the room so for the meantime I will look for ways to improve the flexibility and driveability of the existing lump as well as improving the looks

Post by **katanaman** » Sun Apr 29, 2007 6:07 pm

This has been covered a few times on the old forum. I know Spag has or had one but cant remember if he used it and Eliot has done something similar http://www.mez.co.uk/ms1.html. The throttle body can be bought quite cheap on its own from various places as well so you don't need to go for a kit like your picture.

Lewis · Post by **Lewis** » Sun Apr 29, 2007 6:07 pm

Thanks - I'll go have a root on the archives for it! Cheers for the link as well - really is fantastic, just what I was looking for. Credit to Elliot for documenting that, exactly what I'd like to do!

I saw the issues regarding the manifolds with the short, single plane runners giving low torque outputs on something like his big 'ol truck-of-war but that shouldn't be as much as a problem in my sub-1-tonne motor, I would have thought?

I think I'd keep all the carbs ancilleries though to retain that 'stock-ish' look and just block everything up as appropriate.

That's the stuff

I guess multipoint into the manifold runners would be much better so that'd probably be the direction I'd be looking

Lewis · Post by **Lewis** » Sun Apr 29, 2007 10:14 pm

I've been doing some heavy reading into that Auto-Nomics 4 barrel, 4 injector setup - seems a real doozy and cheap as well (relatively, 200 quid for the basic assembly with lines).

Of course, injectors and machining for IAC rack up the cost a bit.....along with a few other ancilleries.

Nice bit of kit though

Getting myself into a right tizz now though, suddenly quad downdraught style using gutted Dellortos or Gixxer bike carbs has filtered into the equation now.

Oh the humanity!

Spag · Post by **Spag** » Mon Apr 30, 2007 8:02 am

Hi,

The Autonomics is cheap and cheerful and was 'lemon squeezy' difficult to bodge on in place of the std rover plenum (well was with Megasquirt anyhow!!!)

http://spagweb.com/v8mini/gallery/05/01_tb/index.htm

http://spagweb.com/v8mini/gallery/05/02 ... /index.htm

http://spagweb.com/v8mini/gallery/05/02 ... /index.htm

Lewis · Post by **Lewis** » Mon Apr 30, 2007 8:36 am

Hi Spag, thanks for that - looks good!

I know this is a tricky one to answer but would there be any potential gain in power, or has anyone seen any improvement over the standard flapper?

I mean, it'll be part and parcel of changing over to Megasquirt anyway so it'll probably improve a bit with just that!

Seems it could be a good route then - start with the 4 injectors, then when I've got another manifold or the time, stick the bosses in for 8, mock up the fuel rails and switch them over

Post by **katanaman** » Mon Apr 30, 2007 9:23 am

Just using 4 injectors up stream adds a lot of other things that can cause problems so that on its own would probably not be as good as the standard system with MS. If it was me I would weld the bungs in for the 8 injectors for the start. The 4 large injectors are expensive anyway so you would be as well not buying them just get the TB and go the 8 injector route.

Lewis · Post by **Lewis** » Mon Apr 30, 2007 9:26 am

The 4 large injectors are expensive

Aye I saw that - nigh on 30 quid per injector from Auto-Nomics direct anyway.

Fuel distribution did concern me a little, so I think I'll take that advice and go straight to/stick with direct port

Thanks!

bill shurvinton · Post by **bill shurvinton** » Mon Apr 30, 2007 12:50 pm

£120 for a set of injectors is not bad. You will pay £80 to get a set of rover ones cleaned anyway.

TB injection has plus and minus points. It does work well. Fuel distribution is pretty good as the throttle plates shear the fuel nicely. But at the end of the day, if you can get port injection fabricated easily/ cheaply you might as well.

Lewis · Post by **Lewis** » Mon May 07, 2007 12:19 pm

As an update to this - I've ordered a full Megasquirt II V3 kit along with a few other odds and sods.

However, I'm holding off the throttle body for the time being until I can check that I have clearanced for it and an air filter, as my car runs the intake pretty close to the bonnet.

Still, hopefully, once I've got it set up OK on Megasquirt changing over to the new intake system should be a doddle

Thanks for everyone's advice!

bill shurvinton · Post by **bill shurvinton** » Mon May 07, 2007 1:07 pm

MS2 is (TBH) not worth the extra over MS1 for a port injected V8 setup.

Lewis · Post by **Lewis** » Mon May 07, 2007 1:50 pm

Well - the price difference was so negligible I just stuck with the 'newer is better' approach

I'm sure I can find some use for the uprated features, like the integrated rev limiter, onboard driver for IAC and others. I really am looking forward to experimenting with it (as well as using it as the basis for future projects) so I figured it was worth it.

bill shurvinton · Post by **bill shurvinton** » Mon May 07, 2007 7:41 pm

I don't call £50 negligible. They must be overcharging for MS1 whoever you bought it from (guessing not Phil)

You were also mis-sold. MS1/extra has rev-limiting and a dozen options that the MS2 doesn't yet have. The only advantage of MS2 is if you are using a standard hotwire intake which has stepper IAC. For everything else a cheap bosch PWM idle works as well and is easier to fit as it goes inline with a pipe.

Lewis · Post by **Lewis** » Mon May 07, 2007 8:21 pm

Eye up, I got it from http://www.diyautotune.com . They charge $193.00 for MS1 V3 complete kit (including case), which is 97 quid. The complete MS2 V3 was $253.00, 127 quid.

D'ya reckon that is reasonable or rather over the odds. I did shop around quite a bit and thought it pretty competitive. They seem to have a very good reputation as well. These are unassembled, in component form - the fully built MS2 V3 clocks in at 206 quid, which seemed reasonable compared to eBay and various other sources (negating shipping and customs, of course, love relatives

). They included a harness so you can start building your own loom, as well as clear packaging and instructions...

MS1/extra has rev-limiting and a dozen options that the MS2 doesn't yet have

This IS interesting though - These are the things they list as 'new' compared to the MS1 on their site:

24 MHz HCS12 processor,
- Fuel control to 1 µsec (100 times more resolution than MegaSquirt-I),
- Ignition control (full spark timing advance control, dwell control, etc) for one coil/distributor (7 pin HEI for example) and Ford's EDIS systems,
- On-board stepper motor driver for IAC stepper control (this requires a few jumpers to be added on the MegaSquirt PCB to connect the socket jumpers to the DB37 connector),
- Ford PWM idle valve firmware support,
- Built-in rev limiter, either 'fuel cut' or 'spark retard',
- All tables are now 12×12 in size,
- WBO2 AFR target table (in AFR units),
- Independent dual-tables for VE and AFR target,
- EGO feedback in wide-band mode is proportional to the differencebetween the measured AFR and the target AFR, the bigger the difference, the bigger the feedback step,
- Spark advance table can have different rpm and kpa bins than VE and AFR tables,
- 115,200 baud serial interface with MegaTune2.25+,
- CANbus networking
- Barometric correction amount and direction configurable in software, and provisions for:
- barometric correction based on initial MAP reading,
independent 2nd barometric MAP sensor for continuous real-time baro correction, or no baro correction.
-TPS values for open loop and flood clear mode are user configurable,
- MAP based open loop can be set as well as TPS,
- Both TPS and MAP based accel enrichment is built into the code, you can configure the ratio of each,
- Blended Alpha-N and speed density is an option,
- 2 spare I/O lines for custom controls. (This is in addition to 4 lines for Idle stepper control if you don't need this, or the Fast idle solenoid then becomes a spare if you do use a stepper motor.)

Seemed pretty compelling to me - then again, the majority of those things might be something the average user will never even look at, let alone use....but I might play with them.

But if it's the case that the above is incorrect and not quite a true sale, then do say, might be inclined to do something about it

Eliot · Post by **Eliot** » Mon May 07, 2007 9:00 pm

You manifold selection criteria should be based on your intended use. Single plane manifolds are generally for achieving peak power at the expense of torque (and likely driveability) low down.
Dual plane returns the low end drivability - but (at least on a chevy) tend to max out around 5500rpm.

I would strongly suggest you get 8 injector bosses added to the runners (dry intake) rather than fitting them onto the throttle body (wet intake). The latter is effectively an electronically controlled carb and is less desirable than port injection.

Use the Autonomics TB - its a nice piece for the price. Bill Stocks them I believe.