drilled my FPR today - Honda Prelude Forum

schwett · 12-02-2001, 09:42 PM

took out my stock FPR. cut the cap off to install the b&m. also drilled the endyn style relief hole. i went small for the time being - about .04"

this dropped my idle fuel pressure to about 40psi. it was 52 or so before. throttle response seems better, actually, but it may just be my imagination. in any case it should be easier for the engine to keep the mix right at idle and other times of low engine load.

as for the work itself, it's not too bad. there are good articles there on how to do it so i didn't bother with a writeup. the only difference for us JRSC guys is that the FPR is a ***** to get off if you don't have the right tools. a 3/8" drive socket won't fit, and a box wrench won't work (hits the throttle cable mount) unless it's a stubby type - 4" or less. i finally went and bought a 1/4" drive wrench with a 10mm swivel socket. much easier.

here's one thing i've learned about working on preludes, esp with the JRSC :

you can NEVER have too many types of 10mm wrench! i currently have four different wrenches, three socket drivers, 5 sockets and a bunch of extensions. i've used them all and HAD to use each one at least once.

LuderSH · 12-06-2001, 10:18 AM

Ok Schwett, I got a question for you: If you return your car to stock (i.e. no supercharger or Wabro) will the car still idle normally with this relief hole?

schwett · 12-06-2001, 10:28 AM

totally stock? no. taking the walbro off would drop the pressure back to stock, and the relief hole would drop it further. it might idle since the car idles in closed loop, but i suspect eventually it would throw code 170/171. the real problem though, would be that at full throttle the pressure would be much lower than it should be. the ECU wouldn't know that though, and it wouldn't be monitoring the O2 sensor, so it would run dangerously lean.

fully stock except for bigger injectors and the b&m on the stock FPR and it would be OK assuming the injectors were larger in proprotion to the decreased pressure at idle and you set the static FP properly for the injectors.

however, if i put the car back to stock i'll just buy a new honda FPR. it's like 80 bucks.

Quote:

Originally posted by LuderSH
Ok Schwett, I got a question for you: If you return your car to stock (i.e. no supercharger or Wabro) will the car still idle normally with this relief hole?

LuderSH · 12-06-2001, 10:57 PM

Quote:

Originally posted by schwett

fully stock except for bigger injectors and the b&m on the stock FPR and it would be OK assuming the injectors were larger in proprotion to the decreased pressure at idle and you set the static FP properly for the injectors.

So did you buy the b&m?

schwett · 12-06-2001, 10:59 PM

yep put it on last weekend. at the moment, it's not doing anything but sitting there, "open," as i saw when i pulled the vacuum line on it and nothing happened.

Quote:

Originally posted by LuderSH

So did you buy the b&m?

LuderSH · 12-07-2001, 12:12 AM

So is the B&M a neccessity when drilling out the stock FPR? I read the how-to over at Endyn and it seems easy enough, but I don't remember it saying I need one of these.

schwett · 12-07-2001, 12:16 AM

no, it's not a necessity. however, if you drill the hole too big you won't have a way of raising the pressure at idle without the B&M. as an experiment, i just went and adjusted the B&M, and it's now back to 50PSI at idle, even with the hole. pull the vac line off the cartech and it goes to 70, and under boost it'll be about 100. so now i can adjust all three of those points. if i wanted to lower the idle pressure any lower than 36 or so, i'd need to drill a bigger hole. at some point though, i'm sure the size of the hole defeats the ability of the b&m to increase the pressure.

Quote:

Originally posted by LuderSH
So is the B&M a neccessity when drilling out the stock FPR? I read the how-to over at Endyn and it seems easy enough, but I don't remember it saying I need one of these.

LuderSH · 12-07-2001, 12:25 AM

Man Schwett you are ON THE BALL! You've got about a 5 min. turn around. Thanks for the help. I'm following in your footsteps btw.

schwett · 12-07-2001, 12:32 AM

just DON'T do what i did and drop a 10mm box wrench into the engine bay, beneath the intake manifold where it will take you an hour with a coat hanger to get it out. rather than F around with a wrench, just get a 1/4" drive socket and swivel head 10mm and do it easy the first time.

Quote:

Originally posted by LuderSH
Man Schwett you are ON THE BALL! You've got about a 5 min. turn around. Thanks for the help. I'm following in your footsteps btw.

LuderSH · 12-07-2001, 11:23 AM

Quote:

Originally posted by schwett
rather than F around with a wrench, just get a 1/4" drive socket and swivel head 10mm and do it easy the first time.

Will do, actually I have access to a VERY well stocked garage where I do all of my car work. It's amazing how having the right tools makes the job so much easier.

When are those 370's going in??? I'm starting to get anxious.

schwett · 12-07-2001, 01:31 PM

excellent. every time i do anything i find that it takes waaaay to long, then i get pissed and go to sears and spend $$$$ on tools and it's a piece of cake. i've ammased an impressive collection of 10mm wrenches and sockets!

i need to get one of those magnetic pickups too.

my injectors may show up today (thanks 98luder!) but more likely next week, so i'll put them in next weekend. i think i'll also do the hondata gasket while i'm there. it's been a nice coaster, but time to put it where it belongs.

Quote:

Originally posted by LuderSH

Will do, actually I have access to a VERY well stocked garage where I do all of my car work. It's amazing how having the right tools makes the job so much easier.

When are those 370's going in??? I'm starting to get anxious.

Smilez · 12-08-2001, 01:47 PM

Does the JRSC come with the walbro pump? Or is that something you chose?

schwett · 12-08-2001, 05:50 PM

it comes with the pump.

Quote:

Originally posted by Smilez
Does the JRSC come with the walbro pump? Or is that something you chose?