16v ITB questions

[Sprinter Freak]

Hey guys

Putting a set of silvertop ITB's and a few other things on my bigport 16v 4age. Am wondering if the stock injectors are going to be up to the task or do i need to go bigger?

Also wondering if it will be better to run an adjustable fuel pressure regulator rather then the stock one?

Lastly, i have been reading about people not using the IACV when running the vac lines off the throttles. would this cause the car to have a rough idle?

Cheers

Ryan

[drift kid]

Which injectors are you planning on using? And I don't see a problem with the stock fpr but I guess an adjustable one wouldn't be bad either, as long as it had the capabilites to run stock pressure

[Dylan]

If your not changing anything else the stock injectors will work just fine, an adjustable FPR won't be better than the stock one but its up to you.
Running the vac lines from the throttles won't cause a rough idle, but it may be too low when cold which you can adjust the throttles open slightly more if needed.

[Matt]

Stock fpr will be ok, and injectors too. What other work you done to the motor and what ecu will u run?

[ill-minded]

Lack of ISCV won't make a rough idle per se, but it'll mean that you have to compromise either a low, boggy idle when the car is cold and a normal idle when warm, or a normal idle when cold and a high idle when warm. There are other ways to try and bump the idle when cold, but they only work to a limited extent. If you can't be buggered setting up one of the variable type ISCVs, you can opt for a simple solenoid actuated on-off type which is super easy to wire to just about any aftermarket ECU, or in failing that, a thermoswitch mounted in your coolant system. The extra air being fed into the intake runners - whether via a balance tank or not - shouldn't affect MAP sensor readings by any significant amount either.

[Sprinter Freak]

I was hoping to use stock bigport injectors (210cc low impedance if i remember correctly), unless there going to be running near full duty cycle. i thought you needed a higher fuel pressure to make the most of the bigger cams and more air from the ITB's? have already bought this so will probably put it on and set it to stock fuel pressure.


okk sweet thats what i was hoping, only putting mild cams in TODA 272 degree with 7.9mm of lift and a set of silvertop ITB's. ah ok, thats not a big issue, its a track car so gets warmed up completely before getting used.

The motor is just a freshly rebuilt 4age smallport bottomend with a 4age bigport head, 272 degree 7.9mm lift toda cams, silvertop itb's and a set of samq velocity stacks either 70mm or 130mm depending if do a brake booster delete. ECU will probably go for a haltech sprint 500 or a platinum pro 1000.


ah ok i get it, so its a bit of a trade off. Putting in a thermoswitch will probably be the easiest, will give that a go.

[tottacrolla]

I have a similar set-up to yours and I'm using stock smallport injectors 235-250cc (there seems to be some confusion about this) I'm also using the stock smallport fpr.

[Sprinter Freak]

Did you have to use the injector resistor with the smallport injectors?

[Dylan]

Won't have to use the resistor pack with the smallport injectors as they're high impedance

[tottacrolla]

As stated above, no resistor required.