looks like you been busy once again, hopefully this setup will work for you this time. i been busy in the shed painting a xr6 i got so i can piss it of and put the money form it into the lexus. good times, NOT!
What type of fuel management are you using. Secondly double check your bypass valve vac line and it should open during idle.
No aftermarket FPR going to be direct bolt on. I do have some used one if you want. However, I suggest u get a new one from the dealer. Save u lot of headaches. By the way, I made this earlier. http://www.youtube.com/watch?v=h9anHP6Mlac
Sorry I meant aftermarket performance AFPR. I am pretty there are aftermarket FPR for the Lexus application. I am glad u found the problem. Your car dyno already? Nice....
As for me... NO turbo.. just NA for now..
I totally don't think 315 cc/min injectors without the FMU will be enough for 10 psi. Here's the standard calculation of the injector size at the crank HP:...What would be the better setup, OEM FPR with Supra 315's (fuel computer for adjustment) or stock injectors with aftermarket rising rate FPR? I am making about 10psi and haven't had fuel issues until like 2 days ago, but I would like to upgrade to be safe.
...KC
I totally don't think 315 cc/min injectors without the FMU will be enough for 10 psi. Here's the standard calculation of the injector size at the crank HP:
(HP x B.S.F.C) / (no. of injectors x .80)
In your case of forced induction, you'll need to have the BSFC of .60. For example of 400 bhp, the above calculation will be like this:
(400 x .60) / (8 x .80) = 37.5 lb/min => 37.5 x 10.5 = 393.75 cc/min.
You'll need 8 of 393.75 cc/min injectors to fulfill 400 bhp.
However, with the rising rate FMU, the case will be different. The max psi of boost to be used with the FMU is 9 psi. Going higher than this will put you at a big risk as recommended by the pros. I just learned this from them and applied it successfully in real life. For example, if you use the FMU with the 12:1 ratio at 9 psi, you'll have the fuel pressure of (12 x 9) + 40 of stock fuel pressure. This will be 148 psi of fuel pressure. The more boost you'll run, the more fuel pressure you'll have. I've been using the FMU with stock fuel injectors at 6 psi with no problem.
If you can trade for the Supra TT black injectors, I think each one is 440 cc/min.
If you didn't have the FPR issue before supercharging, then more likey the supercharging caused the FPR to go bad. You can try to unhook 1 section of the intake pipe and leave it open without any connection to the supercharger as in stock condition. Then abuse your car to see how the stock fuel react to it.Well, I have no idea how much hp I am really making, but at 9-10psi, I have not had fueling issues until recently because of my OEM FPR.
So, since I have not had fueling issues with the stock injectors and an OEM FPR that has likely been going bad for awhile now, I would think that a new OEM FPR and 315 injectors would be a benefit to me. I would set the mainscale on the MAFTPro to -20% or so, and should have all the fuel I would need for boost.
I am in no way an expert, and I don't doubt the math, but the above statement would, to me, seem true.
Please correct me if I'm wrong.
Thanks,
KC
If you didn't have the FPR issue before supercharging, then more likey the supercharging caused the FPR to go bad. You can try to unhook 1 section of the intake pipe and leave it open without any connection to the supercharger as in stock condition. Then abuse your car to see how the stock fuel react to it.
You can try the 315 cc/min injectors with the new FPR, but like I mentioned, you're risking the engine, although the AEM gauge says the ratio is good. It might not last. I bought a set of 315 cc/min injectors and planned to use them with the FMU to max out these injectors at 12 psi and hope they'll be good enough. However, I changed my mind because the fuel pressure will be too much, and I didn't want to risk the engine. I'm looking into adding the extra injectors using the Split Second. You already paid thousands $ on the system, why would you save a hundred $ for a big risk?
The fuel pump could be the problem. The Walbro 255 lph/hp is the best bang for the buck. Here it is. http://www.lextreme.com/walbro_255_l.htm. After your fuel system is completely ready and if these issues still happen, then you'll need to look into other issues.Well, the FPR has a rubber diaphram (I assume), rubber goes bad and dry rots over time. The car is 13 years old. I didn't have any problems with any of the vac lines before supercharging either. But, put some boost on the old, worn out rubber and problems happen.
On the injector question, all I am saying is, I haven't had any fueling issues with the stock fuel system, until recently of course. Could be that the low CFM output of the v-9 has something to do with it.
All that being said, the new FPR DID NOT fix my problem. I'm going to drive home from work running in speed density (not using the MAF) to see if anything changes. If it does, my MAF may be acting up again.
The only other thing I can think of would be a fuel pump problem.
Please, if you have suggestions, let me know.
KC