Putting a turbo intake on a TBI car?

[22dodge]

all ford trucks in the 80s and early 90's used bank fire injection... the v-8's fired 4 injectors at one time, then 360°(crank degrees/180°cam degrees) fired the 2nd bank of 4 injectors. there would be a computer issue with that much current thru 4 injectors, chances are pretty good you would fry the injector driver... but heck be a leader: try it and let everyone know how it works or doesnt work. if you don't try it, you'll never really know... don't count on someone else to do all the work and research at some point someone has to try it to see if things work, why not be a leader?

[Una]

Quote:

Originally Posted by turbovanman You would have to get the smallest flowest injectors you could find, the log injectors should be ok when used with an AFPR. You have to make sure that whatever injectors you use, add up to the same as the TBI injector or you will fry the computer. Theres nothing wrong with batch fire, OEM's used it for years, cheap way of firing fuel injectors. They went to sequential for better fuel economy and emission controls.

log injectors are 27lb.. Way too big still.. MAYBE 19lb injectors would work.. I used Buick 19lb injectors in my Megasquirted SC.. And Megasquirt bank fires the injectors.. I have it setup to fire injectors 1 and 3 together, and 2 and 4 together. Actually injects 4 small squirts per intake valve opening.
Why is it a bad idea to run mpfi with the turbo intake on a TBI computer? Well let's see.. Injector impedance.. You're likely to blow the injector driver, or the injectors as the low impedance injectors work with a system called peak-and-hold.. They get full current for a moment to pop them open, then a modulated current to keep them open without burning them out. Get that wrong and they can burn out or you can burn out the driver. (Part of why I chose high impedance injectors for my MS'd car, less to have to configure) Next comes injector size, you need 4 injectors that flow the exact same as one TBI injector. I'm sure someone can look up what the TBI injector flows. To get your 4 injectors to match that closely, you'll probably need an AFPR. The price of an AFPR is more than the price of a megasquirt! And lastly, there's this thing speed density fuel injection systems use called VOLUMETRIC EFFICIENCY.. You want MPFI because it's going to make you engine more powerful, ie, more efficient.. That's where the computer is going to have some issues. Say you adjust the fuel pressure to get a decent idle, at 5,000rpm, the engine will be flowing more air than it ever could have with that TBI intake, so suddenly it won't have enough fuel. Turbo or not, it will be open loop at full throttle, the O2 sensor won't save you here. Ok, say you adjust the fuel for the proper amount at full throttle 5,000rpm.. Your idle is going to suck!
But hey, knock yourselves out, I just want to be able to point, snicker, and say "I told you so"..

[turbovanman]

Quote:

Originally Posted by Una log injectors are 27lb.. Way too big still.. MAYBE 19lb injectors would work.. I used Buick 19lb injectors in my Megasquirted SC.. And Megasquirt bank fires the injectors.. I have it setup to fire injectors 1 and 3 together, and 2 and 4 together. Actually injects 4 small squirts per intake valve opening. Why is it a bad idea to run mpfi with the turbo intake on a TBI computer? Well let's see.. Injector impedance.. You're likely to blow the injector driver, or the injectors as the low impedance injectors work with a system called peak-and-hold.. They get full current for a moment to pop them open, then a modulated current to keep them open without burning them out. Get that wrong and they can burn out or you can burn out the driver. (Part of why I chose high impedance injectors for my MS'd car, less to have to configure) Next comes injector size, you need 4 injectors that flow the exact same as one TBI injector. I'm sure someone can look up what the TBI injector flows. To get your 4 injectors to match that closely, you'll probably need an AFPR. The price of an AFPR is more than the price of a megasquirt! And lastly, there's this thing speed density fuel injection systems use called VOLUMETRIC EFFICIENCY.. You want MPFI because it's going to make you engine more powerful, ie, more efficient.. That's where the computer is going to have some issues. Say you adjust the fuel pressure to get a decent idle, at 5,000rpm, the engine will be flowing more air than it ever could have with that TBI intake, so suddenly it won't have enough fuel. Turbo or not, it will be open loop at full throttle, the O2 sensor won't save you here. Ok, say you adjust the fuel for the proper amount at full throttle 5,000rpm.. Your idle is going to suck! But hey, knock yourselves out, I just want to be able to point, snicker, and say "I told you so"..

All good points but if we listened to everyone that said don't do it, we wouldn't have 9, 10, 11, 12 sec TD cars and minivans, right?

[Una]

They aren't turbo.. I could just imagine someone trying to add a turbo into that equation.. <shudder>

[turbovanman]

Quote:

Originally Posted by Una They aren't turbo.. I could just imagine someone trying to add a turbo into that equation.. <shudder>

I realize they're not turbo, I am merely saying that if we listened to the naysayers, we wouldn't have fast td's, they would be all dead and buried,

[DaytonaTurbo87]

I was thinking about it more, and I'm thinking about not going ahead with this. Not because of the work, cause this is my daily driver and I rely on it every day and it need it to stay ultra reliable like it has been over the years I've owned it, but also because our winters here is manitoba are cold, and I don't want to give up the heated air intake and the coolant heated intake manifold, cause this car takes long enough to warm up in -20-30* temps as it is now.

[Una]

The reason you get away without a heated intake on an MPFI is because the fuel is injected directly at/into the intake port, it doesn't have time to freeze inside the intake on it's way though the intake. Just some interesting info...

[88-16V-Lebaron]

Just add the turbo and intake with an 85 head (grab wiring from any year 2.5 turbo). This would lower your compression and definitely up your power. If you are going through the grief at least get the HP.

If you want high NA HP throw in a 3.0 24 valve motor with wiring from a stealth. (222 HP stock) and then throw on Kevlar timing belts to ensure motor life. I have seen some very rough bodied NA stealths for close to a grand complete for parts.

Another option is to put on a 16V head and grab the computer from an early 2.4l caravan to control the fuel portion using the stock distributor.

Of course it would be better to just use the complete 2.4l with wiring from an early caravan/stratus and get 150HP NA without going through the hybrid hell.

[Una]

Quote:

Originally Posted by 88-16V-Lebaron Just add the turbo and intake with an 85 head (grab wiring from any year 2.5 turbo). This would lower your compression and definitely up your power. If you are going through the grief at least get the HP.

LOWER COMPRESSION is BAD on an N/A engine. Do NOT swap a G head onto a TBI car. Your shooting yourself in the foot. More compression makes more power on an N/A car.

[88-16V-Lebaron]

Quote:

Originally Posted by Una LOWER COMPRESSION is BAD on an N/A engine. Do NOT swap a G head onto a TBI car. Your shooting yourself in the foot. More compression makes more power on an N/A car.

He said that he wanted reliability and to use his T1 manifold. I said to add a turbo so that he could use the same NA block for trouble free operation. The addition of the 85 head would lower the stock NA compression (9.0 down to 7.5?) to make it ULTRA safe for adding a stock turbo with his T1 manifold for longevity without the issues of fueling.

Then just use a stock 2.5 wiring harness and fuel pump. If you take good care of it you can 250K + MILES out of a T1 setup stock. There is no reason why his NA shortblock could not produce a measly 150+HP and last for the next 75K miles or more on a NA engine with 200K (assuming the oil was changed with a new head gasket).

I think it would be better for gas mileage to run a 2.4l from a carvan/stratus for ultimate NA reliability with stock 2.4l wiring. The 2.4l motors/trans out of a 96 vehicle are CHEAP and pretty reliable stock with an extra 50HP to boot.

[88-16V-Lebaron]

Quote:

Originally Posted by Una LOWER COMPRESSION is BAD on an N/A engine. Do NOT swap a G head onto a TBI car. Your shooting yourself in the foot. More compression makes more power on an N/A car.

You forgot the part where I said ADD THE TURBO to the NA block to lower the compression. I think making the point of LOWERING THE COMPRESSION indicated that I knew what a G-head would do because of its larger bowl size. IE DURABILITY with added response/pep over a TBI for short money without even pulling the motor. You can get a mitsu turbo, pump and wiring for about 150 or less. MUCH cheaper an the MEGASQUIRT route, great durability and easy on the technical side considering the other options.

[Una]

Quote:

Originally Posted by 88-16V-Lebaron He said that he wanted reliability and to use his T1 manifold. I said to add a turbo so that he could use the same NA block for trouble free operation. The addition of the 85 head would lower the stock NA compression (9.0 down to 7.5?) to make it ULTRA safe for adding a stock turbo with his T1 manifold for longevity without the issues of fueling.

Your math is off.. The G head is reported to take about .5 off the compression.. So 9.0 down to 8.5.. Still too high for safe turbo operation.

[88-16V-Lebaron]

Quote:

Originally Posted by Una Your math is off.. The G head is reported to take about .5 off the compression.. So 9.0 down to 8.5.. Still too high for safe turbo operation.

Sorry about the compression mistake, but nonetheless it is still a viable option for safe street operation but maybe not 20PSI of boost.

If you add an intercooler and keep the boost up to maybe 15 PSI then 8.5 is well within the safe operating range, no intercooler than the stock boost is still safe. The G head is also less prone to detonation. For an extra margin of safety you can also retard inital timing. I still think that it is a valid way of increasing HP on the cheap using easily available parts.

[DaytonaTurbo87]

lol, I'm actually gonna be doing a turbo conversion on a rampage, but in the mean time, I was considering something not as involved as a turbo swap for the daytona. But for now I might just have to live with the tbi.

[Una]

That's what I've chosen to do with my TBI Omni.. No need to put any money into something that isn't broken. I megasquirted my '83 SC because the carb's they put on those things are a nightmare. Brand new they don't work, when you finally do get them to work, they stop working by themselves for no apparant reason. Annoying.