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In God We Trust
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I was recently told that I could put TT 360cc injectors into my base 95 3kgt. Can I do this? Will it screw up the fuel/air ratio in the MAS==and as a result would I need to replace the MAS with a VPC and control the ratio with an S-AFC? Confused.:confused:
 

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Yes you can do that. It is possible to put in 360cc Injectors on an N/A without needing the S - AFC. If anything it would be bright to get the S - AFC but there is no rush to it. Some people have done it on the board successfully.;)
 

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Yes there was some kind of disagreement with them. You might want to do a search for it and read some of the comments on them. I cant remember them off the top of my head. ;)
 

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luisitol said:
wasn't there some discrepency wiht the tt injectors on the N/As?
Yes there was but people have been doing it now for around 8-12 months now and have had no known problems to be had because of the known discrepency.

If any one knows of any problems linked to it please educate me.
 

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Adding larger fuel injectors will produce NO gain. Our cars (and any car for that matter) don't have any problem injecting fuel. Cars are always designed to inject well over the necessary amount of fuel (running lean is very dangerous). Fuel tanks are pressurized, and a liquid, think about it. What I'm getting at, is that its really easy to get fuel into the cylinder, its hard to get AIR into the cylinder. Thats why people use things like turbos and superchargers to compress air, or nitrous, which is composed of about twice as much oxygen as atmospheric air.

Now, if you're running a huge nitrous shot, or bolt on a turbo or s/c, then adding larger injectors would allow you to run more boost, because you could add the extra fuel.

.jon
 

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Discussion Starter #7
Jon3k:

So what you're saying is that the fuel injectors are replaced for the sole purpose of increasing boost when a turbo or upgrade equivalent (both of which will increase the air introduced into the engine)is present. Two questions:

1. If I replace the MAS with a VPC and control it with an S-AFC, would I need to consider upgrading my stock N/A fuel injectors? That is, by using my S-AFC...I would be manipulating my air/fuel ratio.

2. Can I use an S-AFCwith a stock N/A MAS without conflicting with the ECU on air/fuel ratios? That is, when adding an S-AFC, should one automatically add a VPC as well?

I hope I'm not being confusing. I know very little about these mods as I am relatively new to 3SI and the import-street-racing scene. thanks for your help.
 

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Wizard of NOS
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VFIB said:
Jon3k:

So what you're saying is that the fuel injectors are replaced for the sole purpose of increasing boost when a turbo or upgrade equivalent (both of which will increase the air introduced into the engine)is present. Two questions:

1. If I replace the MAS with a VPC and control it with an S-AFC, would I need to consider upgrading my stock N/A fuel injectors? That is, by using my S-AFC...I would be manipulating my air/fuel ratio.

2. Can I use an S-AFCwith a stock N/A MAS without conflicting with the ECU on air/fuel ratios? That is, when adding an S-AFC, should one automatically add a VPC as well?

I hope I'm not being confusing. I know very little about these mods as I am relatively new to 3SI and the import-street-racing scene. thanks for your help.
This is exactly what I want to know also+

Ive already have a Supra TT fuel pump, but I want to know.

How big of an injector can someone upgrade to without haveing to change them out?
:confused:
 

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A while back somebody on the board had dyno'd his car after adding bigger fuel pumps and bigger injectors. He had gained 6 horses from what the dyno said. But there is no use to them if you dont plan un going non - N/A sometime in the future. ;)
 

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someone clear this up please
so if we say we add in a a turbo on a N/A car and we dont upgrade injectors there will be a imbalance of the air / fuel ratio 2:1 so what happens is that the engine has too much air and not enough fuel so it runs lean?
and say if upgraded the injectors 360+ and increased the fuel pressure we would end up with the opposite more fuel less air therefore the engine is running rich ?
 

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I have the 360cc injectors on my SL. I am using the S-AFC to run them. The car is running rich, but not to rich. I have an A/F ratio gauge and that is what Hans used to tune the AFC to the injectors. I can not say that you will see an increase in performance. I think the car pulls harder in higher RPM's, but that could just be me. I do NOT have a large fuel pump...yet. I am one day going to make the trip to a dyno when I have the larger pump installed. I will post results then. This is a good mod to do if your going to be running NOS, Turbos, or a Supercharger on an N/A, which is why I did it, but I am no longer going to go the NOS route. The car does crank when I start some times, usually when I park on a steep hill. I was told a fuel pump will solve this???
 

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VFIB said:
Jon3k:

So what you're saying is that the fuel injectors are replaced for the sole purpose of increasing boost when a turbo or upgrade equivalent (both of which will increase the air introduced into the engine)is present. Two questions:

1. If I replace the MAS with a VPC and control it with an S-AFC, would I need to consider upgrading my stock N/A fuel injectors? That is, by using my S-AFC...I would be manipulating my air/fuel ratio.

2. Can I use an S-AFCwith a stock N/A MAS without conflicting with the ECU on air/fuel ratios? That is, when adding an S-AFC, should one automatically add a VPC as well?

I hope I'm not being confusing. I know very little about these mods as I am relatively new to 3SI and the import-street-racing scene. thanks for your help.
Yes - the only reason to need to add more fuel (eg - bigger injectors,pump,etc) is because your inducting more air than the car was originally designed to take in. You'll have to compensate w/ this with more fuel.

If you wanted to switch out your injectors w/ 360cc's, you can easily control them w/ an Apexi S-AFC, which allows for +/- 50%. You can run up to 440cc w/ it - i believe. No need for a VPC at all, the stock MAS is fine.

ILanda said:
someone clear this up please
so if we say we add in a a turbo on a N/A car and we dont upgrade injectors there will be a imbalance of the air / fuel ratio 2:1 so what happens is that the engine has too much air and not enough fuel so it runs lean?
and say if upgraded the injectors 360+ and increased the fuel pressure we would end up with the opposite more fuel less air therefore the engine is running rich ?
Yes - having too much air (or not enough fuel) will produce whats called a "lean condition" during combustion. Not good at all for your engine.

Yes - you would run rich with larger injectors w/o a fuel controller. Let me explain:

Your MAS calculates the air, and tells the injector to pulse so long to inject fuel. Well, normally its using a smaller injector (is it a 240cc?). Now, with an injector another half as large, the same signal will cause much more fuel to be injected. That means you're running rich. By using a fuel controller (Like Apex's Super Air Flow Converter [S-AFC]) you can tell the ECU that you're receiving less air. This causes the injectors to inject a smaller percentage of fuel, but with larger injectors, it comes out to what the stock injectors flowed originally. I hope this wasn't too hard to follow. I think I'm even starting to confuse myself =P

.jon
 

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hey fellas,

stock injectors on a na are fine, when i went to a dyno to tune in my afc i took the 360 injectors with me to install them after i removed the 220s. it turned out that according to the afc i needed to LEAN OUT in higher rpms with the 220s in order to gain hp using the afc. this means that larger injectors will not net you anything without some form of increased air induction.

the problem with installing the tt injectors (note this in IN THEORY, i have yet to hear of a confirmed issue) is that the tt injectors are low resistance while the na are high resistance. it is possible that this may be solved by placing some resistors in-line, that will prob be the route i take when installing the supercharger just to be on the safe side, but there are no confirmations of a difficulty as a result of this.

in answer to some questions earlier:

if using a vpc, you do NOT need to look at upgrading your injectors unless you are forcing some type of induction. a vpc on a na is a pretty serious mod tho and not worthwhile in my opinion.

the s-afc is a stand-alone product that alters the signal sent by the stock mas to the ecu, there is no need to add a vpc. it works fine with a stock mas and does not cause any issues.

btw, jon, great explanations... i think :D... seriously, good stuff. stock injectors on a na are 220cc.

safe travels everybody.

- mike
 
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