Stock injector boost limits?

[inspector-111]

How much boost can you run on stock injectors? And do you need to re-wire the fuel pump even if you upgrade to a 190lph?

Thanks!

Chris.

 

[romeen]

The individual car's set up, state of tune and environmental conditions all make a difference. But about 14 psi is generally considered the safe upper limits of the 450cc injectors. You need a logger to know for sure although plug readings can give you some idea of what is going on as well.

Rewiring the pump regardless of size is generally a good idea to minimize voltage fluctuations.

 

[inspector-111]

And if I change injectors, I MUST have something to tune them with? Is this correct, or is there any way of "cheating" to upsize to say 550's without adjusting anything?
I would like to get a DSM link, but too many $$$ going into the engine rebuild right now.

 

[talontuner1997]

well you can turn up the boost to around 14-15psi safely, But without a logger you shouldnt go past that without knowing whats going on in your engine. a 15psi you dont need to rewire th pump but once you go past that its recomended you do.

 

[LordZed]

well you can turn up the boost to around 14-15psi safely, But without a logger you shouldnt go past that without knowing whats going on in your engine. Dont bother rewiring the stock pump just get a 190 or 255 when your going to upgrade then rewire it.

It's never a bad idea to rewire the stock pump. That way it's already done and there is not drop under higher boost levels.

You're car will run with bigger injectors, but it will idle poorly and you will not gain any real benefit due to the fact that your ECU will still be set for 450cc injestors.

 

[romeen]

And if I change injectors, I MUST have something to tune them with? Is this correct, or is there any way of "cheating" to upsize to say 550's without adjusting anything?
I would like to get a DSM link, but too many $$$ going into the engine rebuild right now.

Yes, most people use the SAFC with 550's because it is cheaper and easier to set up than DSM Link although you really can't compare the two since DSM link works differently and has WAY MORE functions.

I've read that using a 2G MAS on a 1G can somewhat compensate for 550's. But since I have no personal experience with it you may want to do a search on it or maybe someone who knows more about it can provide some input.

 

[inspector-111]

Does "hacking" the stock 1G MAS affect this at all? (removing the lower honeycomb)
Or is this something entirely different?

 

[LordZed]

Does "hacking" the stock 1G MAS affect this at all? (removing the lower honeycomb)
Or is this something entirely different?

It makes a little difference, but not enough to compensate. It simply allows more air to flow through, leaning out the mixture a little actually. You really just have to bit the bullet and get some sort of fuel control. Even a really cheep version 1.0 SAFC will give you some benefit.

(Also) If you are hacking your MAS, remember to read the instruction thread well. There is a plug that needs to be backed out.

 

[marcmsj]

It makes a little difference, but not enough to compensate. It simply allows more air to flow through, leaning out the mixture a little actually. You really just have to bit the bullet and get some sort of fuel control. Even a really cheep version 1.0 SAFC will give you some benefit.

(Also) If you are hacking your MAS, remember to read the instruction thread well. There is a plug that needs to be backed out.

It's probably the cheapest tuning solution you can get if you're short on cash. I wouldn't recommend them to tune anything bigger then 650's with them though, and that's already pushing it hehe.

 

[oldman]

I've read that using a 2G MAS on a 1G can somewhat compensate for 550's. But since I have no personal experience with it you may want to do a search on it or maybe someone who knows more about it can provide some input.

Don't believe it, 2G mas flows up to 33% more and 550 18%.

 

[romeen]

Don't believe it, 2G mas flows up to 33% more and 550 18%.

Just so I understand, the increased airflow that the 2G MAS provides is NOT enough to compensate for the amount of extra fuel delivered by the 550's, correct?

 

[oldman]

Just so I understand, the increased airflow that the 2G MAS provides is NOT enough to compensate for the amount of extra fuel delivered by the 550's, correct?

The other way around, you'll end up running lean without any tuning device at idle and part throttle, you might come faily close at WOT since stock 9.5 : 1 requires about -15% at upper rpms to reach around 10.5 - 11.0 : 1, with that said, it's a dangerous game without tuning/logging capacity.

 

[xdsmlaser93x]

If your looking to get a proper tune with the 550cc injectors buy an SAFC and a logger. If your spending alot of money on your engine dont try to take a short cut on your fuel delivery system, you will regret it. Here is one i found in the classified section - http://www.dsmtuners.com/classifieds/showproduct.php?product=58666&cat=7

 

[romeen]

The other way around, you'll end up running lean without any tuning device at idle and part throttle, you might come faily close at WOT since stock 9.5 : 1 requires about -15% at upper rpms to reach around 10.5 - 11.0 : 1, with that said, it's a dangerous game without tuning/logging capacity.

Thanks for clarifying.

 

[oldman]

Thanks for clarifying.

No problem kid.