3 Simple Questions About Increasing Boost On An R33

[ausdrift]

Ok, I suspect the answers to these are deep within the forums somewhere, so please take pity on my busyness/lazyness and help me out with three simple questions.

Im planning to boost my R33.

1, What is the max pressure I can safely boost my R33 RB25DET?

2, At what boost level should I expect fuel cut to kick in? (ie, without a fuel cut defender, how high can I go without trouble?)

3, What power increase should I see (before and after approximate power if you know).

and (4) anything else to consider ?

My car is a manual turbo R33 RB25DET with pod filter, turbo back exhaust and R34 intercooler.

thanks heaps

[pipster11]

Probably could run 12 but I think that 10 is regarded as the safe limit

[Michael's R33]

no point going past 10 without an ECU or Piggy back unit.

computer trips out and Air/Fuel ratio go spastic..

[gotRICE?]

Yep 10psi will be the limit of the stock ecu generally. Even with a piggyback your barely going to get any gain at all. It will just pull timing and make you go backwards.

[Dajae]

+1 as above for stock turbo. However generally the stock bottom end will take 15 - 18psi, depending on health of motor and tune, and also depending on turbo used... For a period of time, at least.

Ty.

[Bsa]

Boost is just a number but generally on stock comp with stock turbo 10 otherwise it's will miss and go no where. If you where to get a ecu then turn the boost up you will see around the 200 mark with stock turbo

[89CAL]

2 & 3: anyone's guess. some people can go 10Psi no worries. i could only get 8psi. power wise depends as well. while you got a stock ecu id just do the high boost (constant 7psi) mod and be done with it. Get an aftermarket ecu then boost to 12psi and as said you will get up near 200rwkw

[ausdrift]

OK, so Im getting the picture that with my stock ecu, stock turbo I can set my boost from the current 7 to 10 and that should run alright, ie no fuel cut, no bullshit. No one mentioned it, but I hear the stock turbo should shoot out the exhaust at around 12psi, so I guess 10 will be safe for that. This is correct? also

What power do we think my car has now (stock turbo, ecu, R34 intercooler, turbo back exhaust)?

And what might it have on 10psi? how will power delivery/feeling change with this boost up?

I wanna know as I have about 8 weeks left living in Japan and I wanna know if I can safely up the power without killing anything before I ship the car back. paying for mechanical drama would be very bad, as moneys to tight to mention. OK, yeah, I just dont wanna have to budget mechanical failure. I also wanna know if it would be worth it, value for money wise. I would fit a boost controller shortly on returning from japan if I dont do it now, so im working out whats best to do when. thanks

[Dajae]

RB25DET dyno thread would be your best place to look for est. power. But rough guess.. Somewhere around 160 - 180rwkw. You might be better waiting until you get the car shipped. How much money are you willing to throw at the car? Any specific goals you want to meet?

Food for thought

Ty.

[Mick_o]

Without a tuned ecu its pointless upping the boost really from my experience with my car once ya got an exhaust cooler and filter u should be around 160-170rwkw my car was running 11psi was nistuned and made the same power on 8psi my car was boring as bat shit till 5500 then took off ! save ya coins for an ecu & tune then look at the boost increase

[ausdrift]

The goal is to have as much fun with it drifting as I can. I can probably do it three more times before i gotta put it on a boat and leave. Ive been concerntrating on suspension work all along rather than power, but recently Im getting a little tired of the stockish power. I want to be able to spin it up easier in 3rd gear. Seeing as Im never going to own a car and live in japan again, it seems like I should just go for it and get the extra power.

When I get to aus I will slowly think about engine/tuning stuff.

[GTScotT]

you should be able to hit 9 or 10psi, make 180kw (with TBE FMIC + fuel pump) and be reasonably safe

the stock turbo is very delicate and you should reconsider bothering...

FYI Mick_o is tuning is car to 25psi+ this week, SimonR32 also runs 26psi - both on OEM RB25DET sump/rocker. Mick has GTX71 + E85, simon has T67 + E42.5. Long story short im sure boost pressure is not that important given all the other (read many) variables are in check.

[joeyjoejoejuniorshabadoo]

just remember that it's pounds per square inch

so 10 psi on a stock turbo is very different to say 10psi on a T88

[defari]

If u run 10psi and it miss fires there are other problems I.e spark plugs, coil packs etc. tbh 3psi increase with a fairly stock setup isn't going to give you the "holy shit the car is soo fast". Yeah sure it feels a little quicker but why risk damage for the sake of like 10kw.

As others have said, after market ecu. If u don't want huge power go nistune. You'll need a few other parts to make it compatible but with a tune you'll net some decent gains. Just make sure you bring it to someone who knows how to tune it.

[chris_82]

Buy this-

http://www.ebay.com.au/itm/Turbosmart-Boost-Controller-New-Box-Diesel-WRX-Skyline-Silvia-TS-0101-1002-/190611843917?pt=AU_Car_Parts_Accessories&hash=item2c6159eb4d#ht_2967wt_905

Then do this-

I done it to mine and have exactly the same mods as u except i have a blitz cooler, the power increase is noticable. Run 8-10psi.

Cheap and easy.

[ARTZ]

yeah fully hektik bov ftw

[GTSBoy]

<br />just remember that it's pounds <b>per square inch</b><br /><br />so 10 psi on a stock turbo is very different to say 10psi on a T88<br />

<br /><br /><br />

Whilst everything you say there is true, I am in severe doubt about the scientific reasoning behind your statement.

[Bsa]

You answered the question a t88 would flow a shot load more then a stock 25 turbo like I said before boost is just a number it's the flow that changes how it makes power.

[Dajae]

Boost should really be considered the same way as when dealing with electrical current. 50,000 volts at 0.5 amps is very different to 50,000 volts at 100 amps.

ie; 10psi at 200cfm (for examples sake, stock turbo), compared to 10psi at 2000cfm (T88).

Ty.

[GTSBoy]

I think you guys are missing my point.  Joey bolded the text [bold]per square inch[/bold]. I was wondering what he thought that meant, because it's not really pertinent.