20psi. w/t28, 660's & 190 lph fuel pump sound right?

[LucidEclipse]

Hi guys, I need some feedback on this setup. I have a garrett t28, supra smic (not hooked up yet), 3" gm maf blow through(still waiting for translator but the maf is all setup ) 3" cat eliminator dp., modified brode uicp (for maf) k&n, thats about it for performance stuff. I am also getting a co2 sprayer for the supra ic (I live in Tucson, az perfect excuse for a new toy) well will 660's and a 190 lph fuel pump be enough to run 20 psi? remember im only thinkin 660's cuz we have 91 octane crap here am i on the right track?

 

[larryd]

660s and a 190 should be fine. I used to run 20psi on my Big28 from FP with RC Eng 550s and a Denso 190 pump.

 

[LucidEclipse]

thanks larry, am i right in saying that I need 660's because of the lower octane gas?

 

[larryd]

Need, thats a tossup. Is it a good idea, yea

 

[LucidEclipse]

ok thanks

 

[Unreal]

550s will be more than enough for a t28.

I would not try 20psi on that turbo. But thats just me. I don't even run that much on my setup, and I have 720ccs with a 255hp.

 

[LucidEclipse]

I only think 660's cuz of the shitty octane gas, The bigger injectors the less octane you can run with more boost (as I understand, I read it somewhere maybe rre?) I don't really care about the turbo, I got it for 260 bucks (i know, the guy might as well have given it to me ) So I'm just gonna see how long it will run on that much boost. Plus it's not like every day i'm gonna boost it up to 20, just for the track and streetracing if I break it, well, just an excuse to upgrade to a l1r, super 16g, or other midsize turbo

 

[Unreal]

Size of injectors has NOTHING to do with the ability to run lower octance gas.

Its not about damaging the turbo, its about all the hot air its spitting out at those boost levels.

 

[LucidEclipse]

go to rre, they claim that the bigger the injector, the lower octane fuel that you need. Granted, it will be hotter air, but the supra sidemount combined with co2 spray should easily take care of that.

 

[Unreal]

Explain to me how having a larger injector lowers the octane requirement.

Nothing wrong with going 660s, but they will be overkill.

My friend ran 660ccs on his 16g with no issues besides shitty idle.

 

[LucidEclipse]

this directly from rre's fuel upgrades catalog: Bigger injectors allow you to run ridiculous amounts of boost on cheaper gas. If you are running race gas when you are having fun or if you run higher than stock fuel pressure, you can get away with smaller injectors. East coast kids get 93-94 octane gas to play with, while the west coast gets stuck with diet light pretend 91 octane junk.
In the beginning when it says "Bigger injectors allow you to run ridiculous amounts of boost on cheaper gas" Cheaper gas, I'm assuming that means lower octane, afterall the lower the octane rating the cheaper the gas.
I'm taking the info from the experts, not pulling it out of my ass. I think this is the right setup, I just want some confirmation.

 

[LucidEclipse]

this directly from rre's fuel upgrades catalog: Bigger injectors allow you to run ridiculous amounts of boost on cheaper gas. If you are running race gas when you are having fun or if you run higher than stock fuel pressure, you can get away with smaller injectors. East coast kids get 93-94 octane gas to play with, while the west coast gets stuck with diet light pretend 91 octane junk.
In the beginning when it says "Bigger injectors allow you to run ridiculous amounts of boost on cheaper gas" Cheaper gas, I'm assuming that means lower octane, afterall the lower the octane rating the cheaper the gas.
I'm taking the info from the experts, not pulling it out of my ass. I think this is the right setup, I just want some confirmation.

 

[Unreal]

Well, its not technically right, but go with whatever you want. 550ccs will be more than enough for a t28. Can't hurt anything besides idle by going with 660ccs so if you want those, go ahead.

Hell, just order some 1650ccs and then you can run some 87 mixed with water, and still run 20psi.

 

[Blk_99gst]

I've also read in several places that bigger injectors allow you to run more boost on crappy 91octane. I know a lot of cali tuners say that; but I guess I don't understand the exact reasons behind it.

I would reun 660cc over 550cc regardless of octane, because the 660cc's will give you better timing advance. The 660's allow you to lie to the ecu more with the safc; the ecu sees a lower incoming air flow signals, doesn't freak out as much and pull timing as much. That alone is why I would run the 660cc's.

I run the denso 660cc's in my big16g. They work great, great timing advance, and I idle just fine.

 

[Boosted 1.8]

20 lbs is alot, the fuel sytem is up to par, but not 20lbs on 91 cat piss gas. Maybe race gas. Ease up a bit 16lbs MAX 18.

 

[LucidEclipse]

ok thanks guys, I am gonna go with that setup then. Already found the pump on ebay for $45 halfway there!

 

[nine5raptor]

add water injection and run 22 psi on 91 octane.
a guy here does it on a ported 14b. daily driven. 180,000+ miles on the motor.
510cc injectors. 190lph. tipin timing is 18 advancing to 28 at the top of 3rd with 0 knock sum. its a 90 gsx.

 

[LucidEclipse]

thats incredible. and with only 510cc injectors? damn, maybe 660 is too much, I doubt i will be using safc, as my gm maft will be coming next week. I was also gonna go co2 with a supra sidemount, because I can get a used kit pretty cheap. How do the two compare (i mean, i know how water injection works but co2 will basically freeze the intercooler on contact.) did that guy run his setup on a big fmic, or stocker?

 

[eclipse2via]

Is a rewired Denso 150lph to small for 660's? At 14v it's supposed to be good for 210lph. Thanks, Scott

 

[larryd]

You dont base your fuel pump off your injector sizing. You base it off of how much boost you intend on running and how much power you want to make on what level of gas.

 

[eclipse2via]

I just wondered if injectors that large suffered any instability with lower flowing pumps. I'm having a weird egt elevation and I was wondering if it could be the root of the problem. It does it at wot and closed loop. My DCs are a mildly rich 70% max on a 16G at around 15psi(creeps some) on 91 pump. Thanks, Scott

 

[SPEEDY]

I run 20 to 21psi on my Big28 with 550's and a walbro 255lph fp on pump gas, and the car runs strong. 20 to 21psi is all that I can get the Big28 to hold.

 

[cagri]

the only reason why bigger injectors MAY allow you to run higher boost is that with your S-AFC you can lean out more so ECU thinks there is less air coming in so it allows for a little more timing than if it sees more air coming in. That is the only reason to run bigger injectors. I run 650cc with my big28. I usally run around 17.5 psi max with my stock sidemount. If I run any more, I don't get good timing, and the car seems slower, mainly because of the hot air going into the engine. If I get a front-mount, I will be able to run 18 - 19 psi and still be very safe.