Hello,

I was wondering what's the highest rail pressure anyone dared run on their LNF???

Anyone tried 20 MPa?


We are at 16.5MPa right now.

so far we are injecting 40 deg earlier and bump fuel pressure up.

We have the PW down to 8ms at 7500 rpm, and 300kpa manifold using that pressure and some increase in injector timing got it to rev clean to 7500rpm.


We have to figure out how to fool the ECM into thinking there is less VE flow to prevent it jacking wild at the end when MAF deviates under by a wide margin.


thanks for the help guys!

 

Infinity

 

Might be a better question on the tuning forum, or Hp tuners. I'm at 17.5mpa and that's about all I'm comfortable with, max set at 18mpa. I've gone as high as the max on the injector timing up high I think it's 427° or something, no issues, but I've backed it down to 380° up top.

 

Up to 18mpa should be fine, any thing beyond that starts it potentally get dicey. I personally run 17mpa in my car and have had it there for the roughly 3 years I've been running e47, but then again I'm not making nearly the power you will be. Also, where are you seeing the 8ms pw? Down low or up top?

 

He is seeing 8 ms pulse widths up top at 7000-7500 which is way out of range. He needs to get at or under 6.7 ms up there preferably under 6.4 Ms. I agree no higher than 18 mpa it will not hit more than that normally even if you tell it to. The HPFP cannot reliably put out that much pressure. 20 mpa is too much the pump will dead head at around 2900 psi which is right at 20 mpa.

 

Depending on cam angles and ignition timing you can run up to 385* in the low end and midrange and up to around 420-430* up in the high rpms. Again though cam timing and ignition timing comes comes into play advance it too far and you get misfires.

 

That would be exactly why I was asking. I'd love to see what his PW's look like between 4-5k.

 

Probably not as bad (relatively speaking) because the bigger turbo is just coming on. His IPWs are likely around 7-8 ms right there as well but with the piston speed being much slower than at 7000-7500 it is likely not as big on an issue because he has a longer injection window available. He needs more injection start angle advance as well though he has it only 40* advanced.

 

It's a compound setup so boost should come on much sooner as compared to just a large single. I would imagine his peak torque would be in the 4-5k range.

 

Yes but it is still going to take a bit for the monster turbo to spool up fully. I really would like to see a log of this thing and a copy of the tune in it.

 

Thanks for the input guys!

Ordered those Opel injectors and it should arrive at btf's house this Monday afternoon.

He'll bump it up to 18mpa now that we now it is safe at that level. He wasn't too sure when he bumped the pressure to 16 MPa if that's too much already to destroy the hpfp. At least we now know we can go to 18mpa.

We are now puzzled why the gt2871r is spooling so slow

The system is only getting
4 psi - 2k rpm
20 psi - 4k rpm
30 psi - 6k rpm

I believe the small turbo is about 1000rpm slower in spool.

The 60mm wg has about 25psi spring pressure before it starts opening up.

So it's somewhat puzzling why it's spooling slow

 

We'll remove the spring of the 40mm gate (big turbo's wg) and see if that will help

 

Are you using the factory boost control solenoid or are you on MBCs?

 

We've run over 20 mpa. The pressure sensor maxes, however. I'll have to check my scans to see exactly where the pressure reading stops climbing.