Need some help with regards to converting injectors

[mdefalco25]

So I am in the process of converting my 05 STi to run e85. I am looking to convert my side feed injectors to top feed to assist with the idle and tune. Have heard enough horror stories on big side feed injectors and want to stick to what my tuner is good content with.

With that said, I am looking to do a fuel rail conversion kit of some sort but what I am struggling with is do I need to upgrade the fuel lines as well and are their pros and cons with going with high vs. low impedance injectors? I know P&Ls kit has the resistor box for the low imp. injectors so that is not my concern, but did not know if there was an easier way (cheaper) to just converting the rails and not messing with the fuel lines.

Please let me know your thoughts. I appreciate your help!

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[STIBungy]

Depending on what your power goals are, going to topfeed might be going overboard.

[mdefalco25]

Going with larger TMIC, larger intake, EWG and stock turbo. Really, just trying to get the most out of my stock turbo for the moment. Wanted to stick with 850cc but hear e85 will need more than that.

[the suicidal eggroll]

Depends on your turbo. 850cc injectors will bring you to maybe 350-370whp on E85.

[mdefalco25]

Stock turbo build... Will probably not upgrade turbo and if I do then would go bigger injectors. Just trying to figure out if I can use 850cc instead for stock turbo and still make some power.

[the suicidal eggroll]

Stock turbo should be alright on 850. You don't need to convert to top feed for 850cc either, waste of money IMO. Now if you were going to 1200cc+, then sure, but not for 850.

[mdefalco25]

well, I was under the impression that 850cc would be too small hence the question on converting to top feeds. With the bigger intake, TMIC and EWG was not sure if 850cc would carry me, but for the money to convert wondering if it would be overkill which it sounds like it is. Thanks for your input!

[the suicidal eggroll]

It'll be close. Personally I'd go for more like 1000cc. I was just saying that if you're going to get 850cc regardless, then there's no reason to switch to top feed.

[mdefalco25]

If I go any bigger than they will not be easy to tune for 93 oct. Hence why I was going to do the top feed conversion... I am fine with converting my injectors to top feed, but don't want to upgrade fuel lines if not necessary hence my original question

[the suicidal eggroll]

You don't need to upgrade lines, but you might need some spare 5/16" fuel line to run from the hard lines to the top feed rails, if they don't line up in the same place as the side feed rails.

You'll need a DW301 or Aeromotive 340 pump as well, the Walbro can't flow that much.

[mdefalco25]

That is what I was looking for! Thanks. Already got the Aeromotive 340, forgot to mention that. But thanks for the heads up!

[Scuby04STi]

One thing to remember is that most top feed set ups change to a different end connections, and change the way the hoses are run to distribute the fuel more evenly.

[kellygnsd]

Originally Posted by Scuby04STi

One thing to remember is that most top feed set ups change to a different end connections, and change the way the hoses are run to distribute the fuel more evenly.

If you're talking about the parallel fuel rail mod that can be done on top feed as well as side feed setups.

[Scuby04STi]

Yes, and I know. Just from reading it looked like the plan was to use the stock lines that in most kits are replaced for that specific reason. fuel issue #1 on an STi is that unparalleled stock set up, issue #2 are the side feeds with big injectors. So IMO no point on worrying about the second if you ignore the first.

This is only concerning the fuel system section mounted to the engine not the pump and such.

[the suicidal eggroll]

The series rails really aren't that big a deal until you get to very large fuel pump setups, at which point you should probably be swapping out the FPR and rails anyway.

[Scuby04STi]

I agree, but based on cost and the changes he is already looking into why not change that when your changing most the other problem areas?

[Leafy]

On the low vs high impedance thing, with the ev14's now I wouldnt even consider low imp injectors unless the car was already setup to run them. Buy ev14s and your tuner will love you, the big 2000cc ones can idle like stock on most cars.

[funk32]

how about this kit?
http://www.tougetuning.com/store/inj..._87_96_156_437

[the suicidal eggroll]

Originally Posted by funk32

how about this kit?
http://www.tougetuning.com/store/inj..._87_96_156_437

They're good, but I would buy them from T1 direct, since they're the ones who actually helped develop the kit (along with Maxwell I believe), and will be much better able to answer any questions you may have:
http://www.t1racedevelopment.com/ind...04-06-sti.html

KEEP IN MIND that this is not a real top feed conversion kit, it will ONLY work with the ID injectors that have been specifically modified to work with those rails. The kit works great, but just be aware that if you decide you want to swap to some different top feed injectors later on, it'll have to be to one of the few specially-modified ID ones that are designed for this kit. You can't just swap in any top feed of the street. Even though it's not on their site, T1 will separately sell you the ID injectors that work with this kit (if you want to change sizes), just call and ask.

[CobbsSTI]

I did the T1 race development top feed conversion kit on my 06 STI and I love it. The install wasn't to bad, with the plug n play adapters, lines, rails and injectors. I went with 1000cc injectors running E85 and love them. I made the mistake going with bigger sidefeeds, more like sidefails. The T1 kit is awesome. Highly recommend it.

[k mier]

With the larger fuel pump and e85 the 850's should be enough with the vf39. The 850's are easy to find and relatively cheap. The 850's got me to 434 @ 99% duty cycle, backed off to 420 w/low 90% duty cycle. Stock fuel lines and rails.