Injector sizings - saturated

[Hayce]

Is anyone running big saturated injectors?

If so can you post how big & brand please.


Actually whilst we're at it, what size gate is everyone running?

Apparently Garrett are not happy that the 3076R will be ran with a 38mm gate, they suggest at least a 44mm.
That seems at odds with what I (thought?) I knew.

[BTLF3D]

dont know much about the injectors but can say about the wgate, i run a 38mm and did have boost control problems but im sure that is the shitty wgate placement on my manifold, on your manifold it looks like the wgate placement is in alot better place, there is quite a few people running 38mm wgates on the same motors with no problems??

Another thing, make sure the wgate dump pipe is bigger than the actual wgate outlet.

[Hayce]

Yeah thats what I said, I knew about the dump out of the gate needing to be big but I thought the valve face itself should be pretty capable of handling it.

What injectors you running Hayden?

[nva2nd]

Every one I have sold that size turbo to has used at least 44mm. (2 Honda's when refering to honda's)

Although I have seen plenty using 38mm.

Injector side things I know I can get up to 650cc Saturated from Import Builder. That he recommends far as Saturated goes.

[BB4lude]

im running a 60-1 which i think is a similer size? although not ballbearing and im running a 38mm it spikes a little bit but nothing to worry bout and im sure its only because of the placement on the manifold its on an h22a if that matters

[Antz]

I run a precision SC34 which is a pretty good size turbo (supports 450hp or so) and running 38mm gate have had no issues.
I know of another bosoted honda with a bigger turbo that runs 38mm as well and pretty sure it goes OK.

My research has indicated that if you are going to run lowish boost on a big turbo you should have a bigger gate (maybe that is why they are recommending a 44), as you will have a lot more flow to get rid of/not use. - I could be wrong though, hahaha

(sorry running peak and hold injectors, so cant help there either)

[turboteg]

when i was looking for bigger injectors the biggest i could find in saturated was 750cc from rc engineering, they are quite a bit dearer than low impedence injectors tho!

as for the wastegate question, i run a 38mm gate and it does creep to 13-14psi on a 9psi spring with a precision sc61 turbo, but the outlet pipe is only 38mm id and its plumbed back in to the exhaust! it's not really an issue for me as i don't run any less than 14psi anyway!

what boost are u hoping to run, and what sort of hp you aiming for!

[Hayce]

Thanks for the reply's guys.

Not really aiming for any hp figures, just whatever comes out of it really.
For day to day use I figured I'd run it at about 12 psi or so but in saying that I would like to have the option of 20 odd psi, just to see where the money went...

Make any sense? Basically I wanted to build it to support whatever the stock sleeves would take but in reality I would back it off for day to day use (if that ever happened )

So from these posts, what I've been told and found from my own looking around a 44mm gate might just be necessary. As the car will defiantly see low boost on a regular occurance basis, bugger.

The only reason I was trying to avoid the peak and holds was to save me hacking up the loom to run the resister pack, it seems that its pretty un likely to that I'm either going to find big enough (800+) saturated injectors & if I do the PFC might struggle to control them at idle.

[turboteg]

with that turbo and that manifold i dont think you'll have any problem running 12psi on a 38mm gate!

750cc saturated rc injectors will be ample for what you're trying to achieve with stock sleeves, and if you do go to low impedence injectors i'm sure we managed to wire up the resistor box without cutting any of the factory loom, i'd have to check on how we done that tho!

[Hayce]

What about 20psi though?

Also the turbo has a wee .63 ex housing. I orginally went with the 3076R instead of the 3540 because I thought I'd be able to avoid all this kinda carry on with the smaller turbo... I've not seen it yet but apparently it just as big as the 3540

Do you have some experience with that Manifold? I've not found anyone here who knows anything about them... all I get is one eyed clowns telling me the runners are too big.

I've also not mentioned it but an AVC-R is in the mix for boost control too.

Heh whilst I'm going, the old BOV I have is a Greedy type s, it looks like a dinky toy and I've been told that that is more than likely a bit too small for the new setup too, agree?

[BTLF3D]

im sure 800cc sat injectors would be fine for your power... i run 780cc.

[turboteg]

i don't know what 20psi will equate to on your setup, but realistically you don't want to push it over 450hp@wheels on stock sleeves for reliability reasons, so 750cc injectors will easily support that!

i haven't had any experience with your style manifold, but like hayden said the wastegate looks like its pretty well positioned, probably better positioned than mine and with a similar sized turbo, so in theory you'd expect it to be better, in reality tho who knows! lol

at the end of the day tho if you are still to order a wastegate you're probably better to go for a 44mm one!

as for the blowoff valve i run a small gfb one with no problems at all at 25psi, again it would possibly be better with a bigger one but i just haven't got round to changing it!

[Kelsonmassif]

just go peak and hold with the resistor box, I've read that saturated aren't up to par with peak and hold at higher cc

Stolen from h-t

Formula's:
Minimum Injector size based on Engine HP & BSFC
______________________ WHP x BSFC x 10.5
Injector Size (cc/min) = --------------------------
_____________________ # of Injectors x .80 (duty Cycle)
And dont forget this one:
CC/Min from lb/hr
(lb/hr) X 10.5 = (cc/min)

@ 43.5psi Rail Pressure, Xwhp at 80% Duty cycle w/ differnt CC injectors.
250 - 144whp
300 - 173whp
350 - 201whp
400 - 230whp
450 - 259whp
500 - 288whp
550 - 317whp
600 - 345whp
650 - 374whp
700 - 403whp
750 - 432whp
800 - 461whp
850 - 489whp
900 - 518whp
950 - 547whp
1000 - 576whp
1050 - 604whp
1100 - 633whp
1150 - 662whp
1200 - 691whp

@ 60.0psi Rail Pressure, Xwhp at 80% Duty cycle w/ differnt CC injectors.
250 - 169whp
300 - 203whp
350 - 237whp
400 - 270whp
450 - 304whp
500 - 338whp
550 - 372whp
600 - 405whp
650 - 439whp
700 - 473whp
750 - 507whp
800 - 541whp
850 - 574whp
900 - 608whp
950 - 642whp
1000 - 676whp
1050 - 710whp
1100 - 743whp
1150 - 777whp
1200 - 811whp

[Hayce]

Hmm those above charts seem to be a bit off from RC's calculator. Also the car had 550's in it @ 170wkw and they would get up around 85% at times, but still thanks

TBH I would've thought I could have gotten away with 680's, 880 is a monster of an injector but it's what has been suggested.

I am still to get the gate yea but I might have to revist it once its in the car. The gate placement has it shooting off straight at the radiator and it looks like pretty close quarters down there.

[turboteg]

i really don't think you need to go to 880cc, thats what i run and at 550@wheels they get to 85% and that is on lower than factory rail pressure of 40psi.

those above charts and most of them that you'll find are very generous in my opinion!

my last setup which had 550cc saturated injectors from a rx7 made 430hp@wheels on factory rail pressure, they were running at high 90s% duty cycle tho!

[Locust2000]

The more boost you run the smaller gate you need. I'd think the 38mm would be fine for running high boost but at low boost i'd be considering the 44mm.

my rail pressure is somewhere around 50psi and i'm running 440's. They get close to 100% duty cycle though and thats around 210wkw.

[Hayce]

Thanks again guys

I realize the high/low boost - gate situation, I just had it in my head that the turbo was small enough to still allow for a 38mm on low boost.

I'm pretty set on sticking a 44mm on it just a little concerned with spacing...

Heres a pi of the gate port, I know zero about fabrication but to me there doesn't seem to be an awful lot of real estate there to swap the flange over.

[Locust2000]

Nice looking manifold. I wouldn't be able to comment on what would physically fit but i'm guessing you'd have control issues with a 38mm due to the placement of the WG. It's on a 90 deg angle and it's located off 1 runner, thereby not making it an easy track for the gases to naturally flow through.

It is a nice looking manifold tho...

[d16a7]

locust.. that collector is a merge collector... and that wastegate port actually appears to be at the base of two of those pipes.. therefore it will be in one of the best places to get the gases out for a wastegate that comes off the actual manifold

as as for getting a bigger wastegate.. would putting a 38mm flange.. bolting it up then getting a small bit of pipe the flares out to 44mm do the job or not? somehow i dont think so.. but worth throwing the idea out there

[Hayce]

^^ bang on yea its coming straight out of the merge so all four ports are open to it.

Well the turbo came in so I've grabbed a gate and dummied everything up on the motor, the 44mm will fit as far as dump pipe etc, it won't be exactly as I pictured it but near enough.

I did have a Greedy type S BOV too but now that too damn small as well so I've picked up a tial 50mm.

Apparently it's no problem to mod the mani for the new gate, fingers crossed it all fits in the bay


EDIT: sorry d16a7 I missed your question/suggestion there. Yea it might work, probably be to far into teh radiator though and I think if I were to do something like that I'd remove the gate flange and extend the gate port out a little, maybe bend it down and to the right, may as well put it where it fits.

[Locust2000]

I'm aware of the type of collector it is. If i'm not mistaken, i've got the same on my integra. I wasn't sure if it was at the base of 1 or 2 of the pipes, but that doesn't make a big difference as to my point.

What I was getting at is that with a collector like that, it's already putting the wastegate at a disadvantage(not being able to pull exhaust easily from the full flow of gas) and the fact it's on a 90 degree(also making it harder) just means that the wastegate is going to have a harder time responding quickly and as efficiently as it could. So that, coupled with the fact that other people with a similar size turbo running 38mm gates tend to have creep/spike, i'm just saying that it makes it more likely to happen on this setup with a 38mm.

I'm not knocking the collector at all, I think they're awesome for a few reasons. All i'm saying is it will probably make it a bit harder for the wastegate to do it's job and respond as quickly / efficiently as it possibly could.

I seem to have a tendency to get overly analytical of things so I think i'll just stop now

[americ_ian]

where do u propose it should be>?

[b16a2]

Originally Posted by Locust2000

I'm aware of the type of collector it is. If i'm not mistaken, i've got the same on my integra. I wasn't sure if it was at the base of 1 or 2 of the pipes, but that doesn't make a big difference as to my point.

What I was getting at is that with a collector like that, it's already putting the wastegate at a disadvantage(not being able to pull exhaust easily from the full flow of gas) and the fact it's on a 90 degree(also making it harder) just means that the wastegate is going to have a harder time responding quickly and as efficiently as it could. So that, coupled with the fact that other people with a similar size turbo running 38mm gates tend to have creep/spike, i'm just saying that it makes it more likely to happen on this setup with a 38mm.

I'm not knocking the collector at all, I think they're awesome for a few reasons. All i'm saying is it will probably make it a bit harder for the wastegate to do it's job and respond as quickly / efficiently as it possibly could.

I seem to have a tendency to get overly analytical of things so I think i'll just stop now

lets say a car is runnign 12psi, there will be 12 psi being fed into the engine, whathappens to it then??? it gets pushed out, then what... it hits a restriction, a turbine wheel, so your probly going to have at least 12psi, and by my reckoning alot more in the actual manifold

some people seem to portray gasses in a manifold, like water trickling down a waterfall, sure in that case its hard to divert flow at 90deg, but when there is a huge pressure, gas will go where the least pressure is.. sure i admit a gasses momentum will to an extent hinder it changing 90 deg immediately, but i think WG positioning, is a little over thought and criticised unecessartily some times

that said go bigger then 38, and another influencing factor on the WG efficiency is what come after in, and how it is plumbed into the exhaust, the WG is just a valve, what happens downstrem from it has a huge effect on flow through the valve

[Locust2000]

Originally Posted by americ_ian

where do u propose it should be>?

I don't propose it should be anywhere else. I'm just saying it's something to keep in mind when choosing the size or figuring out how quick it can respond. The only reason I mentioned it was because it's debatable if a 38mm would suffice and I think i've somehow sidetracked myself away from if a 38mm is able to flow enough gas and started to wander into efficiency of design(which would put the WG coming off at a 45deg or something instead of 90). I should stop posting when while i'm doing 5 things at once. Also i'm in the middle of designing and writing some new software for a company so my brain is in the 'optimize everything to be as efficient as possible' mode.

[Hayce]

Haha no worries I guess the debate is over (for this car at least) as I have a 44mm looking at me.

To answer you Luke, there's no down pipe for the car at the moment, the 44mm protruds a little bit more into the DP path so it will need to be slight "kinked" to get around it. This is the main reason why I originally wanted a full race as the gate placement is a little different and the turbo is positioned parrellel with the motor, this peak boost one puts the turbo on an angle.

I'm planning on routing the gate back into the exhaust too, further back the better no? I know I'll probably lose a bit of power from this but I'm fine with that, rather that than fuck around with wof's, cops and the noise... I'm old leave me alone.