Hey all,


My engine will be dropped out of the car in the next few weeks for my coolant pipes to be welded in (elbows included.) I'll also install some larger turbo inlet pipes at this time. I was searching the forum about Fuel Injectors but I couldn't find much on a "upgrade / change" outside an Ethanol conversion. I would like to replace them at the same time.


My knowledge is very limited to modding this part of any engine for the most part.


I am looking for some feedback on;


1) Type and specs that anyone has installed. Why was this your decision in the end.


2) Is larger necessarily better or will I be compromising safety?


3) Does the ECU compensate for any offset of flow need or possible over flow.


4) When does it make sense to replace the stock FRP to a 5psi version?


My finally goal is not to a quarter mile engine but rather, a strong, efficient, reliable track setup that will endure 25mins of hard driving.


Engine currently has EP2 exhaust, 580evt flash, and GT2RS intercoolers.


Thanks once again everyone,

 

We sell Cobb 1000cc and Cobb 1300cc injectors for the 996 and 997 Turbo.

Larger is good if you think you will need them in future, like if you want more power or are thinking or going to ethanol. Tuned correctly there is no safety compromise.

No the ECU needs to be retuned for injectors.

Stock fuel pressure regulator is fine on upgraded injectors.

Hope that helps.

-Mitch

 

Thanks for the info Mr. Mitch. I look forward to being "Schooled" by you experts on this!


Is it mainly price that would make one chose the 1000cc over the 1300cc version? When do you recommend that the Stock FPR be upgraded?

 

The 1300cc's are more difficult to manufacture, so they are more expensive. I have been telling P-Car guys to just upgrade to the 1300's so if you decide to go bigger later you don't have to swap injectors again, as on the Porsche it is not so easy.

We also supply injector scaling's and latenys for our injectors for the stock ECU. This can even be used by a competitor if they wanted.

Hope this helps some. Let me know if you have any other questions!

-Mitch

 

Here is a picture of the 1400cc Motorsports I am using. They are pricey but work extremely well on both pump and ethanol. They are exactly the same on the outside as the stockers so they drop right in and do not require pig tails for the plug like the 750s and 2000s i used before on my 996.

 

The most often cause for changing the FPR is to get more fuel out of the existing injectors to avoid the expense/labor of replacing them. If you are getting injectors that will flow your needs at stock pressure, you do not have to mess with the FPR.

An upgraded FPR is not a "free" increase because increasing the pressure increases the loads on the fuel pumps.

Bigger is not always better, but you want some room to grow most times. If you are on stock turbos and no e85 then a 2000cc injector would be crazy, but you should usualy plan some overhead so if your current build requires 900cc's or so, don't get the 1000's, get the 1300's so you have some headroom.

 

Thanks for the info guys! I had my hose disconnect from FRP and only found it disconnected when conducting a intake pressure test. My hose disconnect after the elbow.


Guess I am okay keep the stock FRP in my situation. Turbo upgrades may be a future plan. With the engine out, injectors would be so much easier to change.

 

Where did you get those?

 

That is a very common problem and most who have it don't even know it as they haven't logged their cars and it doesn't produce a check engine light.

Edit: haha, spelling...wow

 

At what requirement do new injectors become necessary?

Basically I'm like the OP, getting ready to drop the engine and thinking about the addition of some injectors, I'll be running methanol as well, stock block and turbos.
Not sure if my current duty cycle.
No chance of E85
Should I look into 1000cc units or hold off.
I have the COBB tuner and protune, so no issue with configurations

 

Honestly if you have no thoughts of going bigger in the future then you will be fine on stock injectors. But if the engine is coming out and you might do bigger turbos in the future then I would say do them.

-Mitch

 

Once you Mod with a tune and exhaust, what's next?

 

If you want to run E85 even on stock engine, you want to swap injectors.

 

Intercoolers are a must to prevent heat soak and then inlet pipes to take some load off the turbos at higher boost levels and be able to hold boost longer into the RPM range. I would also suggest a custom tune to get the most out of your hardware and octane.

 

with engine out i would do

-weld fittings
-sharkwerks coolant elbows
-plugs and coils
-inlet pipes
-injectors
-plenum ( if you are planning on it)

everything except coolant stuff can be done with engine in the car, however it takes 5-6 hours for someone that knows what they are doing to do injectors on 997TT.... with engine out we are talking 30 minutes. inlet pipes 2-3 hours vs..... 5 minutes with engine out. plugs and coils 4-5 hours engine in vs.... 15 minutes engine out