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-   -   Hows This Fuel Upgrade For My Turbo II (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/hows-fuel-upgrade-my-turbo-ii-14044/)

BlackFC_NYC 08-07-01 04:37 AM

Hows This Fuel Upgrade For My Turbo II
 
Ok, im hoping to do my fuel system before its time for school.

Hows this:

--Walbro High Flow
--Nippondenso 850cc Secondary Side Feed Injectors(what are the difference between side feed then normal?......with stock primarys, 850's ok?)
--Apex'i Super AFC

would i need a regulator?
would this be enough safe fuel to turn my boost up to about 10+ or so and advance my timing instead is retarding it like it is now.

Its a 87 Turbo II
90 Motor, Downpipe, HKS catback, intake, G-force ECU not really working now i dont think, Clutch Masters Stage 2, greddy BOV.

--Mike

soul assassin 08-07-01 05:40 AM

you need top feed injectors unless you are making a custom fuel rail also fc use high impendence injectors 850c is a good size for secondarys for your application, get ahold of rc enginering and they make injectors for our cars up to 1000cc

RETed 08-07-01 07:05 AM

Re: Hows This Fuel Upgrade For My Turbo II
 

Originally posted by BlackFC_NYC
--Walbro High Flow
Great!



--Nippondenso 850cc Secondary Side Feed Injectors(what are the difference between side feed then normal?......with stock primarys, 850's ok?)
Uh, too much of a pain in the ass.&nbsp The stock fuel injectors are "top-feed", so why not replace them with the same?&nbsp Bosch makes fuel injectors up to 1600cc/min!&nbsp These would work with some machine work to the original fuel rails.



--Apex'i Super AFC
Great!



would i need a regulator?
would this be enough safe fuel to turn my boost up to about 10+ or so and advance my timing instead is retarding it like it is now.

I think you're going about this the wrong way...
It looks like you're throwing parts at your car without telling us what kinda power levels and performance you're looking to attain.&nbsp If you got no clue on how much power you want, you're really wasting your money chasing parts...



-Ted

BlackFC_NYC 08-07-01 03:38 PM

Ted:

I just want good power, but safe power.

when i bought my car it was pushing 16 PSI and it was a rocket, the motor blew, and i replaced it with erics 90 motor. (Eric is putting a cosmo in his now). Its never been the same, because my shop retarded the timing, the boost is near stock, and i jsut sucks like this. so what im saying is doing the fuel system, ie: pump, possibly injectors, AFC will increase the reliability of the motor and will be able to put out more boost. no?

what do u think i should do.

Thanks man, Mike
87 Turbo II

gigi 08-07-01 04:05 PM

if you want high boost and reliability you should start with a bigger turbo and intercooler and then build-up from there for your're fuel needs.the stock turbo wont last long past 8psi.i got mine set on 8 using a needle valve and a pop-off valve,i get instant boost,good torque and i can leave it in high gear around town which makes driving in traffic less stressful.

TBoost 08-07-01 04:51 PM

I concur with Ted (as usual). You are going about it the wrong way..

First of all, ask yourself several questions and make them stem around your budget.

You don't need those injectors if you want to just run higher than stock boost. It depends on what kind of boost you want out of the stock turbo (which is limited).

Upgrading MOST of the fuel system should be done with an aftermarket turbo. A better fuel pump is a safe and 1st step in the process to upgrading your fuel system and can be done in the early stages of modding.

-M

BlackFC_NYC 08-07-01 05:57 PM

Ok, so i guess ill just go for the High Flow pump.

If i go for a straight pipe, will i thin out though? will the retarded timing, and low boost?
i got a 3 inch downpipe, stock cat and a hks 60 mm catback.

instead of going to the injectors, and the AFC, ill go for a profec B.
cause i heard u cant really get the best out of a super afc without bigger injectors........no?

--Mike

RETed 08-07-01 11:08 PM


Originally posted by BlackFC_NYC
so what im saying is doing the fuel system, ie: pump, possibly injectors, AFC will increase the reliability of the motor and will be able to put out more boost. no?
1) Figure out how much power you want, FIRST.

2) Those upgrade mentioned above will all work fine.

3) If you haven't seen my other post, the stock turbo and fuel system is only good to about 14psi - keep the boost under 14!&nbsp If you want to run more boost, you need to upgrade the stock turbo to a full T04.




-Ted

TBoost 08-08-01 07:04 AM


Originally posted by RETed

3) If you haven't seen my other post, the stock turbo and fuel system is only good to about 14psi - keep the boost under 14!&nbsp If you want to run more boost, you need to upgrade the stock turbo to a full T04.
-Ted

Uh...I disagree here (what??). That stock turbo is definitely not reaching its speed limit at 14psi. That turbo is bigger than my upgraded turbo (IHI) on my ProbeGT and it can pull 15psi with no problems. In fact, I'm willing to wager that the stock turbo can do 19-20psi before it reaches the limits of the compressor speed. Correct me if I'm wrong. I'd love to see the compressor map of the stock turbo.

As for the stock fuel system. Are you talking about the injectors & fuel pump, or just the fuel pump? I agree that the stock fuel pump won't be able to push beyond 14psi of boost, but I think that the stock turbo would overspin before injectors need to be replaced.

Just my 2 cents, though..:)

-M

RETed 08-09-01 01:50 AM


Originally posted by TBoost
Uh...I disagree here (what??). That stock turbo is definitely not reaching its speed limit at 14psi. That turbo is bigger than my upgraded turbo (IHI) on my ProbeGT and it can pull 15psi with no problems. In fact, I'm willing to wager that the stock turbo can do 19-20psi before it reaches the limits of the compressor speed. Correct me if I'm wrong. I'd love to see the compressor map of the stock turbo.
I do not have the explicit compressor maps on the stock Hitachi turbo, but I have no basis to argue the point on compressor wheel speed.&nbsp What I can state is that you CANNOT compare turbos on rotaries versus turbos on pistons cars.&nbsp A relatively stock 13B can push a 60-1; A 2.0l 4-cylinder cannot, and a 2.5l 6-cylinder barely can.&nbsp There's a different dynamic (exhaust) that comes into play here...

Why I recommend keeping boost under 14psi is because the stock Hitachi carbon seal BARFS at anything more than 14psi.&nbsp Anyone who runs more than1 5psi of boost on the stock Hitachi turbo KNOWS THIS.&nbsp You get excessive oil bypass because the oil either leaks past the compression ring on the exhaust side or (more likely) blast past the carbon seal on the compressor side.&nbsp It really has no basis on compressor wheel speed.&nbsp These carbon seals are very old tech (70's) that were not designed to handle really high boost pressures...




-Ted

BlackFC_NYC 08-09-01 01:59 AM

Well on my first motor i blew it at about 16-17 psi with the stock turbo and intercooler doing like 165+ racing a integra. No it wasent worth the kill.

im assuming i was running lean and i broke a seal on the high way.

so thats why i brought up my fuel question.

i think ill just go got the high flow pump and nothing else.

instead of wasting money on injectos and super AFC, ill go for a profec B and springs.

BTW, my turbo was operating quit well up in those high boost levels. guess i just didnt have enough fuel.

--Mike

TBoost 08-09-01 08:33 AM


Originally posted by RETed


&nbsp There's a different dynamic (exhaust) that comes into play here...

Agreed.




Why I recommend keeping boost under 14psi is because the stock Hitachi carbon seal BARFS at anything more than 14psi.&nbsp Anyone who runs more than1 5psi of boost on the stock Hitachi turbo KNOWS THIS.&nbsp You get excessive oil bypass because the oil either leaks past the compression ring on the exhaust side or (more likely) blast past the carbon seal on the compressor side.&nbsp It really has no basis on compressor wheel speed.&nbsp These carbon seals are very old tech (70's) that were not designed to handle really high boost pressures...


Ahhhhh! Now this is yet ANOTHER factor!! That is definitely true. I've heard of seals being too weak and not able to hold the oil when compressor speeds are very high.

Agreed yet again.:)

-M


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