Question : 3500 & Boost, what fuel supply parts should I use?

[Weatheralls Auto]

A 3500 (using a 3400 pcm tuned with HPT) using 3400 Inj rail, what injectors and fuel pressure will I need if I am boosting it? I was thinking GrandPrix's 3800 SC injectors?

I have a line on a Precision T61 turbo I would like to use.


Thanks.

[Weatheralls Auto]

Anyone have any ideas?
Where is best place to research this?

[1988GTU]

You'll need the injectors that will support your power goals for your engine. You will want to decide which style injectors you'd want to go with as there are two major styles and each have subtle differences in making them operate per requirement.

It's like trying to name your first new born while NOT knowing if it's going to be a boy/girl/hermaphrodite.

The tuner tuning this engine should be able to direct you into knowing what injectors you will need... If they don't know or don't want to give you a straight answer, then you need to take you money else where and run as far away as possible from that person.

[Weatheralls Auto]

I will be tuning with HPtuners,(initial tuning anyways) I am reading as much as I can find, learning and gathering everything I will need.

Biggest issues right now are the flow/type of injectors ( 2000 Impala 3400 engine harness and Pcm) then my next issue will be getting turbo headers made (have not found anything prefabbed yet)
Might have to use stock manis at first, make custom crosspipe and block off rear mani outlet.

Trying to find if anyone else has Turbo'd their 3500 and what they have done.

[1988GTU]

Start out with #28's or #36's and use a front 3500 on the rear and tie it together. Cheapest way around it.


Or you can buy the flanges and make your own.

From there, you should see where you need to be.

[Weatheralls Auto]

you mean flip a front mani upside down and put on rear?

It was my understanding that you couldn't, the exhaust outlets not even,
sorry, I may be misunderstanding you.

[RedZMonte]

well on my DOHC im running the lucas 42.5# injectors... depending on what kind of boost your going to be funning i would say the 42.5# injectors would be the minimum i would run... more boost you would want larger injectors... if you are going to run E85 i would run min. 60lb injectors... check out ZZPerformance.com they are the same injectors. Im also running stock FPR and a Walbro 255LPH High Pressure pump. I would say either the 255 LPH HP pump or a walbro 340LPH would be a good idea as well. the 255lhp Hp are like $100 and the 340's arnt much more..

Like mentioned above it all depends on what your power goals are. Also do alot of research on the turbo... I am running a Stright T4 T04E-Super 60 (60mm). Most of the GP guys are running a T3/t04E (66mm)... that they refer to as a "T66" but isnt a true T66, its a hybrid turbo... get more specifics on the turbo, Inducer/Exducer, A.R.'s ect... spend the time to map out the compressor to the motor. you don't allways need a large turbo to make alot of power and will get better power threw the complete power band not just before red line...

On my DOHC i run 2 front manifolds (stock one on front and another on the rear), i assume the 3x00 motors it would also work... but you need to verify that... if they are Square, Round or D shaped it should work. it is not the best total exhaust flow, but you get equil flow wich is just important. Also they are cast so you won't have issues with them cracking.

S

[3400beretta]

The manifolds 1988GTU are refering to are the header style 3500 manifolds, NOT the log style. You can use 2 front header style manifolds, as the outlet points straight down. You CANNOT use a front log style manifold flipped upside down for the back manifold. The exhaust ports are not evenly spaced, look at a manifold or head and you'll see what I mean.

You can use GTP injectors, I am using them on my turbo 3500, and I have hit 14 psi so far. You need an upgraded fuel pump though. Watch out for fake walbros being sold on ebay and elsewhere. A few members here have already been ripped off. Keep in mind the GTP injectors are rated @ 55psi, so if you run them at 43.5 psi then they will not flow as much. If I remember correctly, the series 2 injectors are larger than the series 3 injectors.

[Weatheralls Auto]

Thanx, I have since seen the new 3500 manifolds on the Malibus etc, I now realize how they look lol,

I was looking at Racetronix pumps, which I think sells real walbros?
My application will be using a Third Gen J body tank and pump assembly, which I think I can take pump module apart and upgrade? anyone know? and if you can, what Pump should I use?


Thanx.

[3400beretta]

Yes you can. You can stuff just about any pump in there. I put a 99 LS1 camaro pump into my tank (94 Beretta).

You should be safe with Racetronix, they are a reputable place.

[RedZMonte]

racetronix uses a venturi style like the Newer GP's run.. just get a Walbro 255LHP and drop it in.. connections are the right ones and the pump is exactly the same size and whatnot as a OEM...

[3400beretta]

GM has been using venturi style setups since the early 90s. That is what fills the bucket, and keeps the pump submerged in gas at all times, even at very low fuel levels. If you do not use the venturi system, you must keep your tank at least 1/4 full at all times. Why do a hack job, when the proper pumps are available.
Some years have an external adapter for the venturi system, in other words you pull off the little "T" fitting from your old pump, and install it on the new pump rather than the venturi fitting being directly on the pump. If this is the case, your options have increased as to what pumps will work.

[Weatheralls Auto]

My system has the "module" design, pump is in the plastic housing with level sensor etc, I am hoping to be able to open it up to replace the pump?

Is there different models to fit?

[3400beretta]

Yeah, they are all like that. Just small differences between years. Your best bet is to pull it apart, take out the old pump, and you will see what I'm talking about. There is a small little hose that comes off the outlet of the pump, and goes back down to the bottom of the bucket. Basically, it creates a venturi system in the bottom of the bucket, and sucks fuel in, keeping the bucket full at all times. A lot of guys who are lazy or just don't know any better, just get a generic pump (they are all the same size) and cut their bucket open, so that fuel will just flow into it from the tank, and just bypass the whole venturi setup. The problem with this, is that you must keep your tank at least 1/4 full at all times, or your risk starving your pump of fuel.

When you take yours apart, you can see if the venturi line is directly on the pump, or if it is a "T" fitting on the main outlet of the pump. IF it is the latter, you can remove this "T" fitting, and put it onto the new pump. If not, you should get yourself a pump with the venturi fitting on it, like the LS1 racetronix pump, etc. That way you keep the system functioning as it was designed. Also make sure you get a new hose that goes from the pump outlet to the upper part of the bucket. 99.99% chance you will not be able to reuse it from your old pump. It is a special clear flexible hose with ridges in it.