What size Injectors to buy

I am just about to purchase some Stage 3 Hybrids form Turbo Technics. I was thinking to make the most of the car I should change the stock 440's injectors to some larger injectors so I can run 1.4 bar or higher!

My dilema is what size do I go for, I know you can get drop in 650cc etc which would be fine but would it be better to buy say 720cc just in case I plan to go single at a later date.

I already have uprated Fuel Pump ,Aeromotive FPR, Profec E01 and a Emanage on the Soop. My plan is to get everything else put on, then get it mapped. What size injectors do I go for - Technical Bods, please advise - V

VORTEX BOYS, What do sale and what do you recommend?

Thanks

The 720's are Greddy? They Flow exactly the same as the HKS 680's So a whole 30 cc more than the 650cc drop ins which you dont have to buy a rail or reistor pack for. 650's will be more than enough for your needs.

HTH

Thanks Terry

I would be right in saying that you supply the 650cc, just out of interest, do you also supply a slightly larger injector that will just drop into the J-Spec Fuel Rail that does not require any additional eqpt.

I am only thinking in advance just in case I decide to go single in a couple of years I want to make sure the injectors I have will be adequate. I read a post by Ian C, he said 650cc would be the smallest he would run on a single.

Please advise me on the above and the costs

Thanks

Yes mate we sell 800cc drop ins at the same cost. The are all £90 inc. each

650's work just fine on moderately sized singles ( T67) unless you intend running silly boost.

Yep, that's what I said, because they are comfortably capable of doing the job Don't read that as "marginal". I've not seen a sensible street single turbo run out of injector flow on 650's yet. Maybe on race fuel at 2bar

-Ian

Both 650's & 800's in stock BTW so never an issue.

Thanks Terry, will fitting the 800cc be detrimental on hybrids, it is just I can see myself going single in a few years, I sort of have a 5 year plan and I am just coming upto 18month in

Ian C, I PM you regarding the Mapping of my Emanage. I have PM you again refernce the date and work

Thanks

I am sorry I never went for the Hi Impedence injectors. The resistor pack is another thing that has the potential to go wrong, so if it can be avoided it should be (IMHO)

You can source the injectors from here if you like:

http://www.greenline.jp/catalogue/bccatpartlist.php?make=Toyota&carcode=JZA80A&intake=FI&category=engine

Scroll down to the Sards...

Price each: about £45 (6x45= £270 for the set) they are on sale, but even when not on sale they are still quite a bit cheaper then UK prices.....

Cost of shipping should be well under £50 for the package

I have used this retailer before with no problems at all.

Only thing is that it would take about 7-10 days to recieve them and you "might" get stung on customs. The retailer does help you in that they "downgrade" the value on the package for customs purposes. I have only been stung about 4 times in more then 20 transactions so it is a bit of a lottery

Or of course if you are pressed for time you can take up Terry's offer as he has them in stock

Its good to have options.

Thanks Terry, will fitting the 800cc be detrimental on hybrids, it is just I can see myself going single in a few years, I sort of have a 5 year plan and I am just coming upto 18month in

 

Ian C, I PM you regarding the Mapping of my Emanage. I have PM you again refernce the date and work

 

Thanks

Gotcha dude, I'll check my calender tomorrow and let you know although I think the date you mentioned is good

By the way, dunno if anyone has mentioned this or not but when you buy injectors, unless they have come straight out of a running engine, get them cleaned and flow tested. *especially* if they are new. OK, it adds near £100 onto the cost of whatever you are doing but to be honest I've not yet seen a set of new or used injectors that *didn't* have one gummed up.

Oh and personally I would stick with the 650's for your goals.

-Ian

Ian,

Would it be fair to say that 650cc injectors would be a good choice because they're nearer to the stock size and therefore easier to trim correctly? (Apart from them being more than adequate for most any realistic power output)

Where would one get new injectors cleaned and flow tested? Can't we somehow test they aren't 'gummed up' ourselves?

So buying new rail and something like 1000cc injectors is a bit of a waste of money, even if plans are to go down the BIG single route?

So buying new rail and something like 1000cc injectors is a bit of a waste of money, even if plans are to go down the BIG single route?

The new rail is fine but 1000cc injectors are very much overkill. To justify those sort of size injectors, you would need to be making around 1000BHP and whilst lots of the Americans claim this, the truth is usually nowhere near that.

I have a T67 turbo on my car and that allows me to spin the wheels at 80mph (not bragging here just highlighting the fact that you dont need a HUGE turbo to make power). To feed them I have 720cc injectors and a twin end feed fuel rail and hav no problems with the fuelling.

At the end of the day, I would forget reading Supraforums and trying to match all those huge powered cars. Those are not daily drivers and, IMHO, that sort of power is certainly not "user friendly" for the streets of the UK.

As Gamer ( very helpfully) pointed out there are cheaper injectors, but we wont use them due to the inferior spray pattern. You need to weigh the pro's and con's of engine longevity against any amount saved.

Rule of thumb, if you have a stand alone, use the biggest injector it will control PROPERLY ( they all differ)

If stock based or piggy back, use the nearest size up to stock your proposed set allows, due to control issues.

HTH, if you need to know any details, please mail me.

Right, I've done a bit of maths and come up with the following:-

440cc injectors at a stock fuel rail pressure should see you OK for approx 323 BHP at 80% max duty cycle using a BSFC of 0.64 (which my car was when stock)

550cc injectors should be good for 404BHP

650's should be good for 477BHP

850's = 625BHP

1000 = 735BHP

1600 = 1176BHP

This has been calculated using the formula's given here

http://www.rceng.com/technical.htm

Obviosuly increasing the rail pressure will increase the potential output of the injectors, as would increasing the duty cycle.

Hope that helps

Tony

Are those BHP figures at the wheels / hubs or at the fly?

Ooops should have said, I guess as there's no allowance for drivetrain they'll be at the crank, or rather theoretical maximums that each injector can support (I've multiplied them by 6 to get a total HP rather than for single injectors)

Regards

Oh bugger please tell me that's not right :|

Ooops should have said, I guess as there's no allowance for drivetrain they'll be at the crank, or rather theoretical maximums that each injector can support (I've multiplied them by 6 to get a total HP rather than for single injectors)

 

Regards

Sorry to sound a numpty here but are you saying that to get a hub figure I would need to take off approximately 20-25% of the bhp figure quoted or are you saying that the fly figure will be plus 20-25% of those figures?

But remember most people run above the stock fuel pressure when modifying. Also, very few injectors have a decent spray pattern at Toyota's static.

Tony, that is too general, what boost pressure are you basing the figures on? Remember the pressure rises with the boost.

I've got 720's @40psi static, and I've got an old datalog seeing 70% duty cycle at max rpm, 1.1 to 1.2bar boost, and it's running mid 10 to mid 11:1 afrs. Really must get some more datalogs done but the weather is precluding this Anyway, the thing is I've calculated that it's about 570bhp at the crank with this setup (using datalogs, online power calculators, and 60-100 timings via a video'd digital display), maybe less but deffo near 550. I think your figures are a little pessimistic, plus 85% is an acceptable duty cycle (although most people here run 100% on their stockers ). 650's should support about 550bhp without maxing out the injectors.

I agree with Terry, get the biggest injectors you'll ever need if you have a replacement ECU, get the smallest ones that'll comfortably do the job if you are using an airflow adjuster piggyback. I wouldn't go past 850cc with an airflow mapper.

-Ian

Tony, I think you may just be using the static rail pressure for your calcs, instead of the actual rail pressure under boost ?

Right, I've done a bit of maths and come up with the following:-

 

440cc injectors at a stock fuel rail pressure should see you OK for approx 323 BHP at 80% max duty cycle using a BSFC of 0.64 (which my car was when stock)

 

550cc injectors should be good for 404BHP

 

650's should be good for 477BHP

 

850's = 625BHP

 

1000 = 735BHP

 

1600 = 1176BHP

 

This has been calculated using the formula's given here

 

http://www.rceng.com/technical.htm

 

Obviosuly increasing the rail pressure will increase the potential output of the injectors, as would increasing the duty cycle.

 

Hope that helps

 

Tony

Agree, 85% on the modern injectors is realistic.

BTW, 650's will support 640 bhp at 85% Cycle, with a static of 45psi running 19 psi boost. 680 bhp @ 2 bar boost.

I've got 720's @40psi static, and I've got an old datalog seeing 70% duty cycle at max rpm, 1.1 to 1.2bar boost, and it's running mid 10 to mid 11:1 afrs. Really must get some more datalogs done but the weather is precluding this Anyway, the thing is I've calculated that it's about 570bhp at the crank with this setup (using datalogs, online power calculators, and 60-100 timings via a video'd digital display), maybe less but deffo near 550. I think your figures are a little pessimistic, plus 85% is an acceptable duty cycle (although most people here run 100% on their stockers ). 650's should support about 550bhp without maxing out the injectors.

 

I agree with Terry, get the biggest injectors you'll ever need if you have a replacement ECU, get the smallest ones that'll comfortably do the job if you are using an airflow adjuster piggyback. I wouldn't go past 850cc with an airflow mapper.

 

-Ian

Sorry to threadjack but I'm gonna be running:

Envy hybrids, double de-cat, veilside exhaust, walbro, boost controller, greddy fmic, S-AFC, apexi power and I've bought 550ml injectors to fit as well. Is this going to be enough or will I need to upgrade again?

What are Envy quoting for these turbo's?. Ask them for the inducer/exducer sizes and the spec on the exhaust wheel & I will answer from there. I am sure they wont mind if they are a genuine upgrade. FWIW Hybrids barely seem worth the effort/costs anymore.