We are actually turbocharging my buddies 96 EFI 460. Nice to see someone else running boost.

We converted to mass-air though with a 90mmm Lighting MAF. The 5.0 F-150 MAF California emissions computer has much better documentation and can still control the E4OD. MAF Tuning is also much easier, and we are using the Quarterhorse too.

I am interested to know how your computer is dealing with the boost? The factory Ford MAP sensor can only read as high as atmospheric, so unless you replaced it with some other sensor, I suspect your fuel tables have just been set to "guess" the fueling needed under boost.

 

Wideband.................

 

Yes, you use a wideband for tuning. That does not change the fact that if you still have the factory Ford MAP sensor, the ECU has no idea what the engine is doing once you go into boost. Whoever did your tune just hacked the fuel tables enough that the ECU just guesses how much fuel should be injected. Not trying to bash you, but it is not really the best way to go about things. That is why generally MAF is a better way to go, at least for Fords. But hey, if it works, it works.

 

LOL. Ouch, I think you may have just opened up a flame war. Being as I don't know in the in's and out's of tuning. I'll show my tuner and see what he says on the subject..

 

Well I will admit I do not know the ins and outs of the SD ECUs. We did not even attempt to play with the SD computer, went right to MAF. Hopefully we will be making boost by the end of this week.

 

Awesome. How much boost are you looking to make? What size turbo?

My truck isn't any kind of pinnacle by any means. I just really like simple things. I like the simplicty of a blower over a turbo. I like to prove how easy it is to make good streetable power with SIMPLICTY without breaking the bank or spending counless hours fabbing stuff up!

5PSI
low octane at the pump $$
No inner cooler.
No msd box.
No extra amp robbing fuel pumps
No needless wiring or MAF swapping.
And it put down some very respectable #'s considering all those factors.

That's what I'm about. MAF is a great thing, I've played with lots of MAF Mustang stuff, but for this application it just wasn't necessary.

 

We got the turbo out of a 7.3 PSD Van Ambulance. The van turbo has a bigger turbine housing, making it a tad better for higher RPM gas engines. Turbos and superchargers are only 50 bucks at the local junk yard. The turbo is remote mounted just behind the cab.

We are looking to run around 7 or 8 PSI initially, so we should be around the same power as you, maybe a tad more as his engine has a stock cam as far as we know.

Our main goal overall was reliability over max power and simplicity. So we have an intercooler to keep air temp and hopefully octane requirement down. We converted to MAF and Sequential EFI to gain a bit more control over the fueling, and we put a shift kit in the E4OD to better deal with the power.

Eventually he wants to get forged internals and turn the boost way up, but that is a long way off.

 

My reason for pointing out "wideband" was to simply state that the truck is verified to have a certain, correct a/f ratio for the altitude (6800 feet) and ambient weather conditions. Speed density tunes are correct at only one altitude and set of weather conditions mandating a 'seasonal tune' unless you make the tune safe at the worst set of conditions. Since the truck was tuned at 6400 feet (a bit lower in altitude) on a hot summer day, its obviously safe for a cold winter day. Your MAF works great with engines until you max out the frequency. On my friend's corvette, the 100mm MAF is maxxed out at 600rwhp at 12,000hz. It cant compensate for anything past that and his car is then speed density to 822rwhp. What happens is the computer uses the last cell in the tune for MAF frequency and then uses that cell's value for all fueling calculations past that. On modern cars, the use of a 2 bar map sensor is the correct way to tune for boost because it reads the boost level as a function of manifold pressure. If its a turbo car that neve has the same boost for a given rpm (not RPM referenced) the car needs to be able to dump fuel based on manifold pressure.

Tuning at altitude isnt the same as at sea level and no its not a simple thing like add 3psi to overcome cylinder pressure losses to make up for it. Its a 28% loss. Anyone who tunes at sea level for a set build and drives to even 1500 foot elevation levels or has big variances in weather has a 'guess' on the tune too.

Your MAF idea is the best of both worlds as it serves to compensate for weather and altitude. Its not on my truck because its a budget build that I simply wanted to share with the forum community. Not everyone wants to do max effort (and cost) builds.

In the end I dont want to be disrespectful to you and I just wanted to share without getting flamed. Starting off by saying my tuner did a hack job isnt cool. I'm just sahring info on a budget build that has verified results. It was to share ideas. Yes there are shortcuts but the a/f is verified and regardless of how its arrived at, the a/f ratio is correct and very safe as is the timing curve, as shown on the wideband.

The tech side of this had input from my friend who is a tuner in the corvette forced induction world (Spinmonster). If he can build a 1000HP corvette, he knows how to tune.

 

Also for everyones info, this build being at 6800ft elevation is why the blower only makes 5psi. At sealevel it would make 7-7.5psi and would be cylinder pressures would be 28% higher to start and the blower would have 28% more air to compress. The results would be about 355rwhp and 455rwtq from the added boost level.

 

You cannot really compare GM ECUs to Fords. They work different, the early GM ECUs max out at 512 grams/s flow on the MAF. Ford MAFs also use a voltage rather than a frequency, and huge MAFs at least on the Ford side are quite easy to get. Not trying to argue, but saying a 2 Bar map sensor is the correct way to tune for boost is not entirely accurate, it is what many of the GM guys do because of ECU limitations, but a proper MAF tune will serve the same function. Just all depends on what hardware you have and what your intended application is to what is better.

I wasn't trying to say your tuner did a hack job either, as obviously it fuels just fine, but rather he "hacked" the fuel tables to work within the limitations of the stock SD system.

Oh, and do not get me wrong, this is in no way a high budget build either. Almost every last thing except the quarterhorse, turbo and shiftkit was bought on ebay. We are at around $1200 with everything. We wanted to go supercharged at first for simplicity, but there were no supercharged vehicles at the junkyard with a big enough blower, and there was no way my friend could afford a new, or used one.

But hey, we're both working with boosted 460s so we're amongst friends

 

Awesome info..........keep it coming.......so whos going to start building EFI 460 turbo kits to order How did these projects turn out?

 

I'd put down some $$ if there was ever a turbo kit for the EFI 460.

 

I have seen pics of several kits guys have built on their trucks, mounting them down under, like STS does. they said they worked well, not sure how much boost they were running. Once you remove the emissions equipment and vacuum res., there is plenty of room to mount a turbo under the hood on the passenger side. Maybe....one day...........

 

All I can say is... WHY waste all that fabbing time only to have boost lag? .... when you can simply bolt on a blower that someone else has already worked out the bugs with, and it's instant power, sounds great, and super simple, tried and true. End of story.

 

You'd need a mighty big turbo to have significant lag - even remote mounted, with a 460. Most junkyards will sell you a turbo for $50-75, and you can get a complete rebuild kit for most turbos for ~$75-$150.

Here's a picture and a video of my friends setup, boost piping not installed yet. Turbo outlet goes right up into the stacks. Turbo Ford 460 Big Block V8 Start Up and Rev - YouTube


There are pros and cons of each. Superchargers bolt up easy, and have instant power. They're also more consistent (and possibly easier to tune). Downsides are high cost, and pulley-swaps will only get you so far if you want more power before you need a bigger blower.

Turbos can be much cheaper (especially if you get a junkyard turbo and rebuild it), don't draw engine power, and are very easy to make big power with if wanted. Downsides are a lot more fab work, you have to figure out an oiling system, and of course there will be some turbo lag.