Jump to content
The mkiv Supra Owners Club

possible upgrade your injectors without using Resistor pack?


randy

Recommended Posts

Guest Terry S

Yes that should be OK. The biggest I've seen though were 550's from RC Engineering. It would probably be just as cheap to get 2nd hand 550's & a resistor pack. Then if you ever want to use man sized injectors you already have the resistor.

Link to comment
Share on other sites

Originally posted by Terry Saunders

Yes that should be OK. The biggest I've seen though were 550's from RC Engineering. It would probably be just as cheap to get 2nd hand 550's & a resistor pack. Then if you ever want to use man sized injectors you already have the resistor.

 

LOL @ 'man sized injectors' :p

 

Mr. 850's :devil:

Link to comment
Share on other sites

It's what you do with them that counts...

 

Can I put my sensible hat on and say get them flow tested as well? I got a set of brand new 550's from Mr. Toyota himself, and one flowed eratically until it got ultrasonically cleaned. Thus justifying the sixty quid it cost.

 

-Ian

Link to comment
Share on other sites

Is it cheaper to get high impedance injectors/resistor pack than low impedance 550's , Ian?

Or did you do it this way for easy upgrade next time?

 

Just curious as I fancy some 550's and if they can be swapped without using the resistor pack ............

Link to comment
Share on other sites

Guest Terry S
Originally posted by matt

Is it cheaper to get high impedance injectors/resistor pack than low impedance 550's , Ian?

Or did you do it this way for easy upgrade next time?

 

Just curious as I fancy some 550's and if they can be swapped without using the resistor pack ............

 

Matt, it's the low impedence injectors that require a resistor pack. The stock J spec injectors are high impedence.

Link to comment
Share on other sites

I just got the UK spec 550cc injectors as they were relatively cheap, would suffice for all I want to do with the car, and were a well-trodden upgrade path. This meant I had to install the resistor pack as well. I don't know what other injectors you can get, I didn't bother researching it.

 

-Ian

Link to comment
Share on other sites

OK Guys! I guess we dont need the resistor pack if we use high impedence injectors. I just checked for injectors on http://www.takakaira.com/

click performance parts then go to the side menu and click [POWER] ENTERPRISE PERFORMANCE PARTS. They have injectors for the 2jz-gte which are high impedence and are available in 550cc 650cc and 800cc. side feed year before VVTI/and after !

Retail for $117 a piece.:thumbs: :)

Link to comment
Share on other sites

Guest Terry S

Good find. Now all we need is an injector expert to tell us if the high impedence are less controllable then the low. There must have been a reason Mr Toyota changed with the 550's, unless it was a cost thing.

Link to comment
Share on other sites

I read something to do with some standalone ECU's, and the minimum pulsewidth at idle - you can't get as good pulse definition with a high impedance injector at really low duty cycles, so you end up with erratic (normally rich) fuelling at idle.

 

Not 100% certain of the above though - surely a low impedance injector with a resistor "looks" exactly the same as a high impedance injector to whatevers driving it?

Link to comment
Share on other sites

Guest Terry S

My stand alone will drive both high & low impedence, you just select what type of injector it is in a menu.

 

I only assume there is a control problem as nearly all high flow injectors are low impedence. There must be a reason for this. I understand what you are saying about the ECU seeing the same thing with a resistor pack, but you guys do know that the UK ECU is MUCH different to the J-Spec. It apparently(the UK) has additional fuelling & ignition timing maps, which aren't present in the J Spec. I know lots of people have installed the 550's with a resistor pack to a J spec, but only Ian C & possible Paul Whiffin have done it properly as far as I know, using a wideband to tune the AFR. I would be interested to see a long term wideband in the car to see exactly what the ECU is doing.

Link to comment
Share on other sites

Guest Terry S

Randy, I don't know enough about injector pulse widths to comment, but there must be a reason for Toyota to spend extra cash going to low impedence & a resistor pack. At the cost of those injectors though I would definitely try it. You will need a S-AFC or similar to trim the fuel. 650's would be ideal as long as you aren't looking to far into the future. What are your HP goals? Also I had sooo much trouble finding side feed injectors, so that in it's self is a good thing.

 

One other thing, make sure your fuel sytem as a whole is up to this. there is no point having 800cc injectors with a stock pump.

Link to comment
Share on other sites

Terry, I am basically looking at 500-550 hp in the future when I upgrade my turbo. So I guess 650cc should be fine? I am already upgrading my pump to a higher flow about 180-200 litres/hr. Will I definately run rich if I did not use a S-AFC? Also pls try to find more info on the advantage of using low Vs high impedence injectors. I don't want to regret anything!:)

Link to comment
Share on other sites

If you do it, randy, then get a fuel pressure regulator and possibly look into getting a bigger fuel rail...not sure what the stock one can support...The j-spec and UK spec are the same but they must become a restriction at some point.

Link to comment
Share on other sites

Guest Terry S
Originally posted by Alex Holdroyd

If you do it, randy, then get a fuel pressure regulator and possibly look into getting a bigger fuel rail...not sure what the stock one can support...The j-spec and UK spec are the same but they must become a restriction at some point.

 

Fuel rail is not an issue. I have a stock one & it has supported upto 690 bhp without issue. Mine has been modified so it has a -6 inlet at either end & a -6 return in the centre. You can use the stock FPR but I have used an Aeromotive one. The reason I chose the stock rail is that I have an HKS one & it just doesn't look as well engineered as the stock item. When it comes to fuel I am not going to play games. ( Anyone want to make me a offer for the HKS one?)

 

:rolleyes:

 

The Stock UK Supra pump is about the highest flowing OEM pump there is. I know Chris Wilson is selling an even higher flowing item. What I would say is be careful you don't buy something like the HKS pump for silly money, which actually flows less than a UK pump. If you are set on only running a single line then an external pump may be best but noisey!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.