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What Turbo

3K views 24 replies 9 participants last post by  dumdum 
#1 ·
ok im sorry if this has been posted but i have not found anything like this yet, i have a 03 wrx and i was wondering about going to a VF34, now can i use my stock fuel injectors? i have a walbro pump in my car, and also on my cobb it has a VF34 setting, what does that mean, can i just buy a VF34 bolt it on, and change my map to that then?? thanks alot guys
 
#2 ·
no you need fuel injectors and an upgraded TMIC would be reccomended along with the tbe.

you can use the cobb map but imo i wouldnt run with an OTS map on an upgraded turbo for long. you wont be getting near the power you should be.
 
#3 ·
ok that is what i thought, i already have the uppipe, TBE intake methanol and a pro tune with what i have right now, i just need a better turbo, so it looks like i should just get big injectors and go with a better turbo and do a nice job of it. what do you think about fuel rails????
 
#9 ·
yes and no. Injectors are not the only supporting mod for a turbo swap.
-up pipe (02-05 only. 06+ it's already gone)
-downpipe
-cat back (often times downpipe + catback is done in one "turbo back")
-fuel pump
-intercooler
-the turbo itself

and most importantly:
-some form of engine management to re-tune your car for the new setup.

That's what you need for a "bolt on" WRX turbo swap
 
#10 ·
im sorry i guess i should of said what i have done, i alredy have a up pipe, TBE, crank pulley, walbro fuel pump, AEM intake, methanol injection, inlet hoses and a pro tune, so you think i should just buy 720cc injectors so they wont have to work as hard then??
 
#12 ·
yea i know im thinking of just buying the tuning software from cobb and doing it my self tuning my friends honda with AEM wasnt that hard at all, and AEM is one of the most confusing EM i know of besides Mega Squirt that is just dumb lol i think anyways
 
#13 ·
You have meth injection, tuned your friend's car with AEM, and still don't know the answer to a simple question like this? That seems kind of backwards to me... Anyway, depending on what kind of honda your friend has, it's likely MUCH easier to tune than the suby.
 
#14 ·
i was just making sure casue i hear like 50/50 from people so i ask questions alot to just make sure, and yea i have Meth on my car, my friends honda is a H23 Vtec with 12.5:1 with his own intake manifold and running DIS on it with AEM, and alot of other things done to it as well, i really dont work on Imports all that much i work on Blown alc fuel injected drag cars and Sprint car engines
 
#16 ·
well actually i just bought two turbos dont ask lol, i got a VF22, and a VF43, i got the VF43 for like 700 bucks, and the VF22 for 800, they are both brand new in the box, now i am thinking about which one to keep and which one to sell lol, the VF43 is the same as a 39 but the wastegate was just upgraded to help with boost creep i think
 
#20 ·
i dunno the new 07 stis with the vf43 are making huge numbers with basic mods. like 300 whp/wtq on stage 2 cars.

i dont know 1/8 mile times but a vf43 would be good for low 12s maybe high 11s with a good driver and all the supporting mods.
 
#25 ·
i dunno the new 07 stis with the vf43 are making huge numbers with basic mods. like 300 whp/wtq on stage 2 cars.
Right but they also have a 6 speed tranny,AVCS and a 2.5L engine with an intercooler sprayer.There is no comparison to the OP's 03 WRX.The VF43 can produce some good #'s.Generally right around small and big16G type power.To the OP: If 1/4 mile is what you want i would stick with the VF43.There is always a trade off with turbo cars.Bigger turbos=more lag=late power delivery.Plus if this is your first AWD and your going to the track,you might want to spend some money upgrading the tranny before the turbos.Anyway what ever turbo you keep a good port/polish/and ceramic coat with some gasket matching would be a must for optimum performance.Same with the exhaust manifolds.Then ditch the factory boost solenoid and get a 3 port one and a nice retune.There are stock turboed 13T 2.0L that are running high 12's.
 
#21 ·
i dont know if you guys alredy know this but if you take your 1/4 mile time and times it by .66 it will give you a really close time to what you will run in the 1/8, say you run a 13.00 in the 1/4, take 13.00*.66=8.58. its pretty close and you just divide your 1/8 mile time by .66 to get your 1/4 kidna cool i dont know lol
 
#24 ·
the ratio of 2/3 in the first eighth and 1/3 in the second eighth is relative to the acceleration of the car. Given consistent acceleration from start to finish, the curve will be parabolic and the car spends much more time in the first 1/8th mile than it does in the last 1/8th. Course cars don't accelerate the same at every speed. Drag cars reach high speeds early and become drag limited. Thus their ratio of front eighth vs back eighth are closer.
 
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