Yellow top injector swap

[DXROLLA]

So im looking at putting some yellow top injectors into my v2 sti ra, would i need a tune straight away?

[kamineko]

yes. tune to the injector size.

some people do just throw them in and say it works, and if your running more boost it might run rich enough at the top end to be safe but your going to have a black rear bumper

if your running enough boost to need larger injectors, the map sensor is going to be a bigger problem

tl;dr it\'d be nasty

[rex-leggy]

you will need ecu and afm to suit. is your wrx a v3? i actually have all the bits ya need for a v3 and am in chch

[DXROLLA]

Nah its a v2 sti ra, ok than was thinking i may need a tune. So best to get them put in once i have enough $ to get a chip n tune from nzefi. Assuming that would suit? I would like to try and get a bit more top end out of it, as once you get over 100kph it just doesnt seem to keep pulling as hard as i would like (on the track that is)

[lachlan]

have you done your fuel pump and filter ?

thatll prolly wake it up a lot .

your 4x 370 injectors + a 100 cc 5th injector arent much down on the total of 4x440 ones anyway

you have a tdo5 aye ? coz a tdo4 wont feel that lively past 100

[kamineko]

 lachlan said:

have you done your fuel pump and filter ?

thatll prolly wake it up a lot .

your 4x 370 injectors + a 100 cc 5th injector arent much down on the total of 4x440 ones anyway

you have a tdo5 aye ? coz a tdo4 wont feel that lively past 100

thought we\'ve been through this in another thread ;p i bet the 5th injector is dead weight

[lachlan]

keep in on topic aye ...post isnt helpfull

[DXROLLA]

 lachlan said:

have you done your fuel pump and filter ?

thatll prolly wake it up a lot .

your 4x 370 injectors + a 100 cc 5th injector arent much down on the total of 4x440 ones anyway

you have a tdo5 aye ? coz a tdo4 wont feel that lively past 100

Yeah have done fuel filter, fuel pump is next on the list, i assume a walbro intank will be ok? Done realy know of any others that bolt in.

And yes as above i think we agreed that the 5th injector is pointless, but will ask a tuner to get there thoughts first.

[kamineko]

 lachlan said:

keep in on topic aye ...post isnt helpfull

not sure what you mean. are you saying the 5th injector should be accounted for when comparing the factory fuel setup?

i\'ve sold all the relevant gear now so i can\'t do any more testing, but when i had the setup, i had a light rigged up to the 5th and would have noticed it in a month or so\'s driving.. so at least on my car it wasn\'t used.

[rex-leggy]

if the fuel pumps working changing it wont make any difference to how much power a car has.

a chip and tune even with standard injectors will make a big difference

[DXROLLA]

 rex-leggy said:

if the fuel pumps working changing it wont make any difference to how much power a car has.

a chip and tune even with standard injectors will make a big difference

I plan on changing the pump more so for reliability than performance, as it is 18 years old, and my understanding is when i get a tune and bigger injectors the pump would be made to work a lot harder than before

[rex-leggy]

 DXROLLA']

[quote name='rex-leggy said:

if the fuel pumps working changing it wont make any difference to how much power a car has.

a chip and tune even with standard injectors will make a big difference

/quote]

I plan on changing the pump more so for reliability than performance, as it is 18 years old, and my understanding is when i get a tune and bigger injectors the pump would be made to work a lot harder than before

yea for sure dude! more sayn that a pump change alone wont do squat

sounds like your on the right track tho

[DXROLLA]

haha yeah trying to do things right and make it as reliable as possible, not chasing numbers just something i can take to the track have some fun and drive it to work on Monday (providing i dont crash ;D) If i had to pick a number for HP id be happy with 300-350hp atw. Do you think this is possible with minor mods and decent tune?

[rex-leggy]

yellows with a tdo5 or similar and tune and 300 should be achivable easily . 350 will take a little more mods like bigger injectors turbo and a link

[DXROLLA]

Sounds good, something to aim for Yeah once i get use to the power it makes with basic mods im sure a bigger turbo ect will be on the cards. 1st things 1st though, got to get it on the track ;D

[Guest]

I thought the yellow p1 440cc injecs didnt seem to flow as much as p2 440cc? Thorpy was the last one on here showing that. Max of 300hp Id say with yellows but really need a tuneable ecu to optimize power curve/keep it safe.

[rex-leggy]

 evowrx said:

I thought the yellow p1 440cc injecs didnt seem to flow as much as p2 440cc? Thorpy was the last one on here showing that. Max of 300hp Id say with yellows but really need a tuneable ecu to optimize power curve/keep it safe.

yea he got 280 atw with stock setup on new engine with yellows and tdo5 on 14 psi . strange tho his injectors were at the limits at that boost yet the same setup on my wagon was safe at 18 psi

[DXROLLA]

So if the yellows could restrict the power, would you recomend an after market injector? I dont want to limit the power and max everything out to make decent power

[Guest]

Yea I dont actually know first hand about it but see a few dyno sheets on p1 they seem to make -220kw with yellows but at lower boost to p2. Always found that odd considering p2 are theoretically higher comp..

[DXROLLA]

Hmm ok may need to do some research before i going buying some

[nztintin]

FYI i ran yellows in my v2 RA with no tune just 13psi boost, ran a bit rough when cold but not bad enough to stall, when warm it was mint.

all we did was change to a v3 manifold and fuel rails.

[DXROLLA]

 nztintin said:

FYI i ran yellows in my v2 RA with no tune just 13psi boost, ran a bit rough when cold but not bad enough to stall, when warm it was mint.

all we did was change to a v3 manifold and fuel rails.

Im guessing not an sti? If it was an sti wouldnt it of gone better on the factory 16psi with stock injectors?

[Guest]

http://www.clubsub.org.nz/forum/index.php/topic,35241.0/topicseen.html

Cheap enough to just buy.

[nztintin]

Non sti, on the dyno run it had spark issues so we stopped boost at 13psi, was trying to get at the fact you don\'t need high boost to compensate for the injectors

[DXROLLA]

 evowrx said:

http://www.clubsub.org.nz/forum/index.php/topic,35241.0/topicseen.html

Cheap enough to just buy.

Hmm yes sounds good, but not sure maybe i should go a bit bigger ???