Adding extra injectors for turbocharged motor?

orvacian

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Anybody have experience with extra injector controllers for high boost applications? I have a 88 Supra that runs 11-12psi now before fuel cut. I wanna get a FCD but I know the drawbacks of that and I am looking to run 15-16psi without running lean and blowing up my fresh motor. My boost controller would be set on 12psi for low boost and 16psi for high in conjunction with the EIC and high would be just to smoke the occational joker who thinks his "stang" or "vette" is fast. It allready kills modded WRX's and pulls on 350z's at 12psi actually. There is a mod using 550cc RC injectors and a Lexus afm but there are issues with that setup like poor idle and such. I like the idea of a stock injection system with a little extra fuel for high boost. Actually I could run a separate tank and use race gas for the extra injector/s only. I am looking for a cost effective method also. Any suggestions?
 

frankh

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Seems to me bigger injectors or higher fuel pressure would be easer. What do you think it runs in the 1/4 mile? 10's
 

jeff

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You probably know about water injection but this is for those that don't... As long as your current injectors can keep a 14:1 a/f mixture at full boost, and assuming the fuel controller can do this consistently without peaks or dips, larger injectors might not even be necessary. Is it running way lean at max boost right now or ??? I don't have any experience with piggyback fuel injector systems (one for street & one for strip) but I've seen some really good results just using a water injection system to control detonation and lower heat at higher boost levels. Intercooler equipped cars need to inject the water (or water and alcohol mix) after the turbo or it'll just pool inside the intercooler. By keeping the temps down, and I mean way down, you might be able to get away with the current fuel system and still increase the boost levels.

You can check them out online - http://www.aquamist.co.uk/ --- Or just search for <i>turbo water injection systems</i>

Aloha
 

Mike_HKmtrsprts

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socalsupras.com look at this page these guys know alot about what your trying to do or if your local to orange county in westminster ther is shop called under pressure that specialize in high performance supras ask for Matt 714-890-5163.....Mike
 

orvacian

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It is probably running low 13s right now (not officially) but from a rolling start it is very fast. I have a WRX myself with bone stock motor and it is WAY slower then the supra. The supra has lots of torque. I am not sure about the air/fuel mixture now but the stock injectors are 440cc which is huge compared to most cars, from what I hear. I know most all of the local socalsupra.com people but this is kinda out of most peoples experience. I was looking for a home-brew solution using easy to find parts also.
 

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tedmales

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i did a new firebird that runs 11s, and gets 28mpg. you guys with your really really loud( you guys call it fast) cars. if it does not run 10.99 or faster, its not fast, i do not if its a 4 banger, maybe an 13 second lawn mower, but otherwise forget it.
 

jeff

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I'd suggest you look into a home brew water/alcohol injection system - it sounds like it'd be perfect for your application and it'd be cheap. They are easy to build yourself and because it just pumps water it's pretty easy to plumb yourself using a reservoir mounted under the hood. I've seen a few do-it-yourself systems and somewhere I have a dyno printout that showed the power difference (more boost with less heat equaled more power) along with an EGT readout that showed how much cooling the home system really provided.

A slightly mod'd WRX can bang off high 12's all day long at a cool track with the right driver. I'm too pu55y to race mine at the strip but I know it hauls ass when it has to. A guy I know with a ECU'd and catless WRX was running low 12's and he eats up clutches, tires, and most of the stock-ish Ford and Chevy V8 RWD hunks-o-junks. And then when it's time to turn it's no contest. Long live Import tuner cars!

Aloha
 

UndercoverFab

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if your looking for cheap and reliable you can just put two extra injectors in the intake tract before the throttle body and activate them off a boost referenced regulator with a hobbs switch, its not high tech and its not pretty but it works, pme me or email me if you wanna know more i think i still have a diagram of how it looks and what you`ll need.
oh yeah this is just my opinion but i`d shoot for a 12.5.1 a/f ratio i know 14.7.1 is considered ideal but i always liked a little cushion unless its an all out race car and your not trying to squeeze every ounce of pwoer out of your setup.
 

orvacian

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TED, first of all it's a inline 6 not a 4 banger. Second, it will easily be making over 325hp and 350ft/lbs of torque from 3 liters of completely stock longblock. Third, it's rear wheel drive with limited slip stock. I would hardly call it a "lawnmower". Third, that Firebird will be in a junk yard after 15 years while my Supra really just needed some some hoses and a headgasket. Fourth, I am sure it is much quieter then your Firebird. 13 seconds is approximately what it does now for a total investment of $3500 including the car itself, wheels, tires, motor rebuild, turbo rebuild and upgrade, 3" mandrel exhaust, etc... It will be faster when I get some more boost.

Jeff, I love my WRX too but you can't say it pulls hard on the freeway. Yeah, it's really quick if you launch it at 5 grand but it thrashes the whole drivetrain. WRX's rule on autocross type of stuff but get knocked off regularly on road courses and such. They just run out of breath at higher speeds. Sure if you wanna invest BIG dollars you can make it fast but why, just sell it and get the STI, which is what I am planning on doing. I just think there was a lot of hype about how fast they are.
 

drtdevil93

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i have always been on the muscle car side, but i have a strong affection for supra's. me and a friend were dressing up and going around to used car dealers to test drive them for fun for a while. god they are fun!! its okay to be love the musclecars, there will always be a place for them. but dont turn your back on technology.
take this into consideration: ive seen lots of supras with 250,000mi. + still going strong.
stock bottomend will hold 700 HP with ease, ive heard of as much as 1200 with an UNMODIFIED rearend.
very good head design, seen many 700 HP supras with untouched heads.
stock trans, from what ive heard, will hold up to 700 ft/lbs
on the make 4 supra (92-97) approx. $2000 in upgrades easily gets you 450 HP
gas mileage still in the 20's.

www.mkiv.com

erik
 

orvacian

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Eric, mine is a 88 MKIII with the 7mgte. Not quite the motor that the 2jzgte is but still respectable. The 7mgte can make up to about 400hp with a stock block and upgraded stock turbo. With a bigger turbo and arp studs with metal headgasket it can make close to 700hp!
 

UndercoverFab

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i couldn`t find the diagram. depending on how much boost you are making this setup may have to be altered a little bit.
on my buddys datsun with a supra straight 6 pushing 18 pounds of boost we used a single 36 pound injector for the fuel enrichment injector(his car also had the equivalent of 26 pound injectors on the engine) he was using the stock ecu with no mods the 30 pound injectors and a boost referenced regulator that upped the presuure 1psi for every pound of boost, for the extra injector a hobbs switch was used and set at 4psi, when 4psi was reached the injector ran at 100% duty cycle, the only time the fuel map wasn`t good was when the turbo went from no boost to full boost, not that we had any problems with leaning it out or surging it was just slightly rich for a split second, anyways his car ran 10.60`s with this setup and we never had a problem with this crude fuel enrichment setup and it only cost about 60$ to build.
also one more thing with the extra injector you want it after the intercooler(if applicable) and as far away from the throttle body that is reasonably possible waching out for anywhere fuel can puddle in the intake. thats about all i can think of at 4:45am.
 

geoff

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please dont do anything thats been recommended....

dont use water injection, it is a bandaid for poor tuning. Also ted, youre an idiot for thinking like that. who gives a damn how many pistons the car has, check the timeslip. youre not fast enough to talk [daddy didnt love me].

The 7mgte is a decent motor with only 2 issues, head gasket and weight. If orings and a cometic gasket are out of youre budget, dont push your luck (no more than 400 at the wheels)

If you want to add extra inejctors the "easy" way (at the tb) then 2 cylinders will run rich, 4 will run lean. You will blow the head gasket in these areas melt the pistons and/or crack the ringlands. Go get yourself a set of big inejctors, like 72lb/hr and an apex'i AFC. I cant remember offhand waht the MkIII supra had for a fuel pump but more than likely it will be sufficient. I am an MSD dealer so i can get you a nice deal on those injectors and a pump if you need. Take the time to tune the AFC with a wideband and you will have no problem making safe, reliable power. If you dont have access to one i have a few friends that may be willing to lend it to you for a day.

A real turbo wouldnt hurt, either. i build turbo imports for a living, so please respect my advice, it comes from working on a lot of a lot of cars with many different setups...
 

tedmales

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Re: please dont do anything thats been recommended....

oh yeah, i forgot that why top fuel dragsters use turbo honda engines. my bad. you honda guys cry how fast your cars are. ha. like i said if its not 10 seconds, it not fast i do not care what it is. you can tell me all about how they make more power per liter, and thats great, but i could care less, i will race any honda in my 34. its one of those slow v-8s, crummy ls-6. when you want to step up, let me know, and if you need some coffee cans for your muffler tips, we have some.
 

Kritter

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Re: please dont do anything thats been recommended....

my brother in law builds sub 9 hondas...not that I like them but they are fast...I think Geoff might be doing the manifolds for them I am sure he will chime in if he does.

Golden Eagle
 

geoff

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Re: please dont do anything thats been recommended....

i built the turbo setup for the current fastest unibody honda, 8.5 and 172.

ted you are an idiot. I mean this from the bottom of my heart, you are truly a moron.
 

orvacian

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Re: please dont do anything thats been recommended....

Ted, Mark Twain said it best: "It is better to remain quiet and be thought an idiot than to open your mouth and remove all doubt!"
 

michael_loomis

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Re: please dont do anything thats been recommended....

Ted thats pretty ignorant of you . as a DIE HARD chevy guy , even i have to admit , the technology in some of those cars is awesome . American car companies are hard pressed to keep up with import HP per liter numbers .

id like to see your "34" hit the road course along with the supra , then hear you talk.
 

Kritter

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Re: please dont do anything thats been recommended....

Aaron you jsut gave me a flash back to "Wilson" on the TV show Home Improvement.
 
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