Injector size for increased boost JRSC LHT

[move over]

I have the LHT JRSC setup on my car making about 7 psi at my elevation in KS.
Stock B18C5
MVM stepper pulley 12% overdrive
Stock ITR crank pulley 5.38"
Kamikaze Header
SMSP 2.5" ID exahust
RC 440cc injectors
Hondata S300
Redline at 8900 RPM - hardly ever go to rev limit
Top blower RPM is 12,727
Currently making 235 HP


I recently purchased the 3.8 nose cone pulley and the gsr intake camshaft.
Max blower RPM will increase to 14,062.
HP will increase to about 250 - 265 estimated.

My question is, will my fuel needs be higher than the RC 440's can supply with the new parts?
What injector size would be ideal?
What is the smallest usable size and still be safe?

I have seen everything listed from 450 - 750cc. Wanted to see what LHT would recommend.

Thanks guys

[MrLHT]

440cc will be fine upto around 270whp while keeping it safe, anything after that I would go with some 525cc.We have found optimal boost to be around 8-8.5 psi, once you push the blower the more boost actually doesn't equate to more power.Look into and ITR exhaust cam with your GSR intake cam and tune it with some cam gears. Spin the blower no faster than 16,500rpms and tune it to keep the boost low but don't blow it out the exhaust.

[move over]

I already have the ITR exhaust cam as it is on a B18C5 motor. I bought the GSR intake just because it flows better than my stock ITR intake cam. And actually, I have the 00-01 ITR intake cam as I swapped it back when I was all motor, so this is probably hurting me even more.

I definately won't spin the blower above what you stated.

In order to tune it to keep the boost at 8-8.5, is this where the cam gears come in? Do you know of any articles to reference? I can't say I have heard of anyone "tuning" to keep the boost low with a supercharger.

If a solid 8psi would be better, I suppose I could trade my 3.8" pulley for a 4"

[MrLHT]

Any good tuner will tune everything on your car, including came gears. The only real way to tune is on the dyno, this way you can see the power increase V boost.Leave the 3.8" on there, you want to spin the blower fast but make the system efficient by using the air produced by the blower.

[move over]

Any good tuner will tune everything on your car, including came gears. The only real way to tune is on the dyno, this way you can see the power increase V boost.Leave the 3.8" on there, you want to spin the blower fast but make the system efficient by using the air produced by the blower.

I datalogged my drive home today.
In second gear, at 8,900 rshared_pm redline, my injector duty cycle was at 79%.
According to RC, you should not use more than an 80% duty cycle. I guess it is time to upgrade before I put on the other parts.

However, my concern is the amount of boost I am making. The maximum my map sensor read, according to Hondata, was 5.9 psi - and that was at 5,800 rshared_pm or so. It then dropped to 5.4 psi for the remainder of the rev range. This level of boost sounds very low considering I have the MVM stepper pulley installed. Granted, I have been relying on the Excel spreadsheet that was created by username "Veris" on honda-tech.com. For my pulley configuration, it shows 7.9 psi without the cooler, 6.9 psi with the LHT intercooler, and 6.8 psi taking my elevation into account. Intake temps were 123F with the LHT cooler.

Does my level of boost sound right to you?

[MrLHT]

Boost on a supercharger is nothing like boost when turbo charging. Compressed air ( boost) building in the manifold is basically air the engine can't ingest. The more boost the more the blower has to work against it to make power. ie. spin the blower as fast as possible and make the motor as efficiant as you can , I have found most power to made around 8.5 psi while not dealing in too much overlap. Dropping boost at higher rpms is normal with a eaton blower.I would like to see what the car is doing on a dyno at that psi. Also what is the max rpms of the blower?