Do i really need a fuel regulator?

[Remix-]

If i am upgrading my RB20DET to GTR injectors which are supported by bosch 040 450hp fuel pump (unsure if they are 32/33) is it really necessary for me to get a fuel regulator (my aim is 320hp at the rears) or will it cause my car to run to rich?

[Roy]

Same fuelling setup as me, on paper the GTR injectors should be good for about 440hp (flywheel), so at 320rwhp you shouldnt have a problem.

[BHDave]

You don't really need to upgrade the reg. Generally they get used in combination with stock injectors to squeeze a bit more out of em. As you are upgrading your injectors then i think it's not really nescessary as your new injectors will be able to flow more than enough for your power goals without additional base fuel pressure.

[omp]

I have a set of RX7 (460cc) non turbo injectors in my RB20DET. The tuner said these are to big for my application. He told me he dropped 1msec on the injector cycle and the car wouldn't idle nicely. It is therefore running overly rich on idle and low revs. I am going back down to CA injectors (anywhere from 320cc-370cc dunno). Is this a wise move? They are bigger than stock so they should be able to support ok horsepower. I want at least 300rwhp(225rwkw). I have heard that the stock RB injectors with aftermarket reg and fuel pump can achieve 250rwkw. Oh yea I have a microtech LTX 12, bosch 040 and malpassi rising rate...thoughts?

[Roy]

Big injectors and idle probs arent typically an injector problem, but the ability of the ECU to control the injectors.

I dont think the LTX12 should be having any trouble at all controlling 460cc injectors... they arent really that big.... perhaps the tuner is struggling with tuning the idle of the engine full stop and is looking for something to blame.... Id try another tuner to tweak the idle and uit should be fine.

[Remix-]

Hijack my thread!! hahaha

OMP, i would recommend you grab a second opinion from a well known import tuner in your area. As Roy stated, your LTX12 should have no dramas controlling the 460cc injectors provided it has been tuned correctly.

[Steve]

I always thought the only purpose for adjustable fuel pressure regs was only to stretch injectors, then along comes a japanese mechanic and D1 pro driver, who recommends I raise rail pressure to 3kg for the sake of added response.

Anyway, something else to consider.

[ylwgtr2]

high fuel pressure = better atomization of the fuel however excessive pressure can lead to a variation of fuel metering each crack open on the injector

[mist]

I've got the SARD regulator with bigger injectors. Not running higher base pressure, but I like the peace of mind that I have a reliable fuel reg heheh. Dont think I need it tho, even on full song my injectors are still on holiday...

OMP- i'm running 550cc injectors on my RB20, ECU is AP Engineering PFC. Injectors have gone up just over 100%, but my tuner has done an awesome job with the staging, idle, etc - tuning work. Running a HKS GT2530 turbo, and I only run around 1 bar of boost so we're probably talking about a similar power range, tho I'm probably making less power heheh. I don't think they're too big - with careful tuning, even have excellent fuel economy!

[Remix-]

mist, What sort of power are you making with those mods?

[mist]

don't know

tuning has been done on the road & on circuit during trackdays with air-fuel ratio meters, etc. has never been on a dyno.