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Deatschwerks 850cc top-feed injectors
Posted: December 10th, 2011, 2:38 am
by Monk BANzai
doing some reading up....are these adaptable to the Legacy? (bear in mind i have a GC8 block)...
http://www.deatschwerks.com/products?cP ... cts_id=195
Re: Deatschwerks 850cc top-feed injectors
Posted: December 10th, 2011, 7:43 am
by VexXx Dogg
methinks you may need to swap fuel rails and intake mani wiring might be the same.
I was pondering a similar move, due to lack of options for side feeds
Re: Deatschwerks 850cc top-feed injectors
Posted: December 10th, 2011, 7:49 am
by russian777
Yeah vexx dog correct , since i am assuming your leggy is side feed
Re: Deatschwerks 850cc top-feed injectors
Posted: December 13th, 2011, 1:02 pm
by Monk BANzai
ahh indeed....yeah Russian we is side feeders....
Re: Deatschwerks 850cc top-feed injectors
Posted: December 14th, 2011, 10:59 am
by ole whore
bro .... figure what u want to do , i was pondering the same but realistically my goals were for dw740 and they are side feed. men running gt30?? using dw740 with supporting mod with no issues. if u need dw850 it means u going 400 - 450whp plus ..... start by asking " meh tranny taking that power" BTW what the block have to do with injectors ?
i hope u not reading this because 850 top feed cheaper than 850 side feed ? the money u will need to convert to top feed will surely not be worth it.
Re: Deatschwerks 850cc top-feed injectors
Posted: December 16th, 2011, 8:15 pm
by DSM_05
bro .... figure what u want to do , i was pondering the same but realistically my goals were for dw740 and they are side feed. men running gt30?? using dw740 with supporting mod with no issues. if u need dw850 it means u going 400 - 450whp plus ..... start by asking " meh tranny taking that power" BTW what the block have to do with injectors ?
Correct. I'm also under the impression that while high IDC (duty cyles) are bad, so are too LOW ones (for flow patterns and whatnot). Again, not sure but that's what I've been told.
If so, you stand little to gain from running those injectors unless you're going with something that's pretty large. We're talking fellas who run 20G's on pump w/ WMI putting out 350+ whp run 740's too BTW...and those injectors (for at least one instance) are almost always under the 85-90% limit.
Re: Deatschwerks 850cc top-feed injectors
Posted: December 17th, 2011, 12:53 am
by nemesis
That be true. Too low is bad as the fuel atomization is poor. And you actually see it when you're tuning. I took a lot more fuel for the same power when I tried to do low boost with the 740's as compared to the stock injectors on a low boost map.
And as mentioned before. What you really going to do so that 740's wouldn't work? If you don't intend on going with a large turbo I'd think even less would be better. Like the 550's or something.
Re: Deatschwerks 850cc top-feed injectors
Posted: December 17th, 2011, 1:40 am
by Monk BANzai
ok... good info...really doing alot of reading on the technical side of power builds and why ppl use the amalgamation of parts that they do. SOme may be overkill and others are a defn requirement if you want to build power.
Are'nt the stock Legacy injectors run at 550's though?
Re: Deatschwerks 850cc top-feed injectors
Posted: December 17th, 2011, 10:44 pm
by DSM_05
^^Not as far as I'm aware. Those cars should come with 380's or 440's if I'm not mistaken.
550/565 is STi territory only.
Re: Deatschwerks 850cc top-feed injectors
Posted: December 17th, 2011, 11:23 pm
by nemesis
440cc
Re: Deatschwerks 850cc top-feed injectors
Posted: December 18th, 2011, 1:15 am
by Monk BANzai
440cc...hmm....then whats the use putting a 255lph fule pump if the duty cycle of the stock injectors does not realyl warrant a high fuel pressure from the tank? Given 440cc i gestimate the most you can get via tuning is about 300whp?...even with WMI?
Re: Deatschwerks 850cc top-feed injectors
Posted: December 18th, 2011, 9:00 am
by VexXx Dogg
I was under the assumption that the legacy injectors were pretty close to the STI's.
I dont even know how this helps, but I'm running the VF37 on a 17PSI tune on stock injectors @ 60% IDC.
Re: Deatschwerks 850cc top-feed injectors
Posted: December 18th, 2011, 10:30 am
by DSM_05
440cc...hmm....then whats the use putting a 255lph fule pump if the duty cycle of the stock injectors does not realyl warrant a high fuel pressure from the tank? Given 440cc i gestimate the most you can get via tuning is about 300whp?...even with WMI?
They are essentially the same as flow WRX injectors (but side vs top feed).
The legacy and WRX engines are both the same, except for head differences and the twin scroll on the legacy.
440cc...hmm....then whats the use putting a 255lph fule pump if the duty cycle of the stock injectors does not realyl warrant a high fuel pressure from the tank?
There's no advantage for a stock setup w/ stock injectors.
If you are on a VF37, there is no way you are maximising that turbo if you have stock injectors.
Is your car tuned? W/ stock injectors on a VF37? You would at least need 565 or better yet, 740's for more headroom. There is where the bigger fpump will come in.

Re: Deatschwerks 850cc top-feed injectors
Posted: December 18th, 2011, 7:19 pm
by VexXx Dogg
DSM_05 wrote:440cc...hmm....then whats the use putting a 255lph fule pump if the duty cycle of the stock injectors does not realyl warrant a high fuel pressure from the tank? Given 440cc i gestimate the most you can get via tuning is about 300whp?...even with WMI?
They are essentially the same as flow WRX injectors (but side vs top feed).
The legacy and WRX engines are both the same, except for head differences and the twin scroll on the legacy.
440cc...hmm....then whats the use putting a 255lph fule pump if the duty cycle of the stock injectors does not realyl warrant a high fuel pressure from the tank?
There's no advantage for a stock setup w/ stock injectors.
If you are on a VF37, there is no way you are maximising that turbo if you have stock injectors.
Is your car tuned? W/ stock injectors on a VF37? You would at least need 565 or better yet, 740's for more headroom. There is where the bigger fpump will come in.

Yep, I am tuned. Running a Vipec standalone EMS and tuned using wideband by a very reliable and experienced tuner.
17PSI on this turbo was the safest tune he allowed based on the AFR's.
Re: Deatschwerks 850cc top-feed injectors
Posted: December 18th, 2011, 8:08 pm
by DSM_05
^^not you. Was actually recommending larger injectors to the OP/Banzai.
Again, for more safety, and to get more out of the setup. IIRC, he siad he had an STi turbo? Vf37? 36?
Re: Deatschwerks 850cc top-feed injectors
Posted: December 19th, 2011, 6:43 pm
by Monk BANzai
DSM_05 wrote:^^not you. Was actually recommending larger injectors to the OP/Banzai.
Again, for more safety, and to get more out of the setup. IIRC, he siad he had an STi turbo? Vf37? 36?
38
Yeah its a hybrid...using the vf37 turbine and impellers and re-machined back into the vf38 housing. So you saying go up in injector size?
another question as we on tuning....can the ECU act as a boost controller? or can you only set where the boost drops off and woudl need a controller to "hold" the boost levels as it were?
Re: Deatschwerks 850cc top-feed injectors
Posted: December 23rd, 2011, 3:07 am
by nemesis
Yes you can tune the ECU to control boost also.
Re: Deatschwerks 850cc top-feed injectors
Posted: December 23rd, 2011, 8:48 am
by Ragnarok
Your ECU will control boost via WGDC,this control still depends on the type of solenoid you running.
Re: Deatschwerks 850cc top-feed injectors
Posted: December 23rd, 2011, 8:58 am
by Ragnarok
Legacy gt's set injector flow constant is 520cc so the flow rate is likely very close to that.
Re: Deatschwerks 850cc top-feed injectors
Posted: December 23rd, 2011, 7:43 pm
by DSM_05
Yeah its a hybrid...using the vf37 turbine and impellers and re-machined back into the vf38 housing. So you saying go up in injector size?
Well if you car carries 440's...and you're using a VF38 housing, then maybe not. The key would be to verify what your actual IDC's are now. That will determine if your injectors should be bumped up in size or not.
another question as we on tuning....can the ECU act as a boost controller? or can you only set where the boost drops off and woudl need a controller to "hold" the boost levels as it were?
The ECU ACTS like a boost controller...a very advanced one....in stock form. It adjusts the WG based on how the car performs (many parameters)....a manual or ele boost controller also adjust the Wgate, but does so at preset values, NOT factoring in the current state of the car.
E.g.
If you get some bad gas, the ECU will trim back boost if the car knocks heavily (in a very simplistic view) so as to protect itself.
If you run a man or ebcontroller, and you get bad gas, you'll continue boosting away happily until you detonate your engine to hell and back. Assuming you don't hear pinging
Reflashing the ECU allows the tuner to set what boost targets the car should be at...so he can raise or lower peak boost.
Using an aftermarket (3 port) boost control SOLENOID (mated to the stock boost control system) allows for tighter boost control...especially under load.
class dismissed.