Got a few qestions for you Guru's regarding BPU

I'm a new too Supra's...So sorry if I seem noobish..

 

Got a few questions before going BPU with a 6spd Jspec RZ non-vvt Supra. I’ve read through many articles here and on MKIV.com but still have a few unanswered questions.

 

So the parlist is as follows.

1. Greddy BCC

2. 3” Downpipe with 2” RR(de cat)

3. Denso IK22

4. Walbro GS341 or UK spec Denso supra pump ?

5. MBC

6. Boost gauge

7. Fmic as the current one is done 4.

 

Planning on 1.2bar boost. This car is only driven on weekends and some weekdays, and most of the time off boost.. 1.2 bar for those special occasions hehehe.

 

 

Now my questions are...

 

1. The bcc clamps the TPS voltage just around 1bar... so the ECU thinks that only 1bar is present in the intake manifold..So if I’m putting in 1.2 bar.. Wont it run lean due to the fact that more is present than the ECU thinks?

 

2. Which fuel pump would be better in terms of noise and performance?

 

3. How well would the stock Jspec 440cc injectors hold up with BPU ?

 

4. In terms of other items, Like oil etc, Would I have to use a diff grade oil now that I’m BPU or would the normal 5w-40 still be sufficient ?

 

5. How well will the clutch hold up ?

 

6. Any other major short comings?

 

Thanks guys...

Hi Follow the hyperlink here > BPU

Hi Follow the hyperlink here > BPU

 

Yip read that...Answered most of my questions but still have a few hence this thread:p

1. The car "overfuels" enough at 1bar to compensate

 

2. Not sure. I've got a walbro and it's fine.

 

3. Fine

 

4. Same grade will be fine

 

5. Should be fine

 

6. More stress on turbos so potentially shorter life span. Seems to be down to luck though.

1. The car "overfuels" enough at 1bar to compensate

 

2. Not sure. I've got a walbro and it's fine.

 

3. Fine

 

4. Same grade will be fine

 

5. Should be fine

 

6. More stress on turbos so potentially shorter life span. Seems to be down to luck though.

 

Ok thanks... that should clear things up.. looking forward going BPU.. can play with the new M3's atleast:d

.. can play with the new M3's atleast:d

 

the new m3's might be a bit ambitious mate but the old ones wont.

 

The walbro is fine although i do find it a bit noisy.

Jspec RZ

 

4. Walbro GS341 or UK spec Denso supra pump ?

Wrong pump mate. You want a GSS342 for a J-spec. GSS341 are for US & UK spec Supras.

the new m3's might be a bit ambitious mate but the old ones wont.

 

The walbro is fine although i do find it a bit noisy.

 

lol...

 

What do think this supra had ? sounded like stock tubbies 2 me

http://videos.streetfire.net/video/Supra-vs-M3_145119.htm

Wrong pump mate. You want a GSS342 for a J-spec. GSS341 are for US & UK spec Supras.

 

Ok thanks man... So then erm wont the denso UK spec work ? Do they have diff fittings or something ?

They will work althou you have to modify the holder a little.

What about mid pipe and backbox?

 

You don't 'need' a boost controller (MBC or EBC) with a Jspec. unless you want a more restrictive restrictor ring (say, to limit boost to 1.0 Bar) and then use the boost controller to raise it to 1.2 when you want

You don't need 3" pipework for BPU. It's a little overkill at risk of sacrificing ground clearance and large flanges that won't fit the cat-back system.

 

The car will run rich above 1.0BAR, so it's quite common for people to fit something like an SAFC to trim fueling at the top end. If you do want to play it really safe, have an Air/Fuel ratio gauge installed to keep an eye on that.

What about mid pipe and backbox?

 

You don't 'need' a boost controller (MBC or EBC) with a Jspec. unless you want a more restrictive restrictor ring (say, to limit boost to 1.0 Bar) and then use the boost controller to raise it to 1.2 when you want

 

Thanks for the comments...So a 2.5" downpipe and a 2" rr ?

 

I have a Blitz NUR Spec Catback on at the mo...Should be sufficient.

What about mid pipe and backbox?

 

You don't 'need' a boost controller (MBC or EBC) with a Jspec.

 

Yes, let God sort it out.

Thanks for the comments...So a 2.5" downpipe and a 2" rr ?

 

I have a Blitz NUR Spec Catback on at the mo...Should be sufficient.

 

EDIT. a 1.2 bar RR should be what size ? I rather play it safe and go for a 1bar and use a MBC since its already fitted to up the boost to 1.2