Jump to content
SAU Community

HOWTO: RB25DET High Boost mode with standard solenoid


paulr33

Recommended Posts

Ok so I did this mod 3 days ago, I have a r34 gtt sedan, doesn't come with a boost gauge, the

Mod worked great then yesterday it felt like it was back to normal, anyway I read some1 posted bout joining the 2 connecting hoses on the solenoids together, so I've done that and my car goes like a rocket,my car has been converted to manual and also had the turbo replaced with another 34 turbo but was told it was reconditioned and had a steel wheel, my car doesn't back fire at all and it feels like its running more then 7psi... I will get a boost gauge ASAP but have I done something that I'm going to regret or not cos I'm loving this power....

Link to comment
Share on other sites

I also did try disconnecting the bottom hose on the solenoid to see what it was like and I hit some kind of cut at around 4200rpm so I put it back on... But now I've connected these hoses it feels amazing and has no sign of cutting out or leaning out, it's real smooth, feels like its hitting full boost at around 3k, is it possible that I have a 32 actuator in my turbo? Also I still have the black wire earthed, only other mods is a k and n pod, still stock exhaust...

Link to comment
Share on other sites

Yep.

1) Get a boost gauge ASAP.

2) If you disconnected the bottom hose and didn't plug it, then you probably had infinite boost (til stuff go boom) cause the actuator would have no pressue to it and wastegate wouldn't have opened.

3) You could have a 32 actuator. (pics?)

Link to comment
Share on other sites

Scroll up ^^^ to post #608 the first pic shows an actuator. (the brassy coloured thingo with the hose going to it)

Looks to be an R33 one. R32 the hose comes straight out the side. (down I think)

Edited by Not a Pulsar
Link to comment
Share on other sites

  • 1 month later...

Finally got around to doing this today. Car feels to pull a but harder when coming out of a corner in second. Haven't had the chance to take it for a big hit yet.

If it's not done correctly it will only boost to ~5psi correct? On my stock 34 boost gauge she sits a little over halfway to +1 which would be around 0.8 bar is that right? Only mods are full 3.5in turbo back exhaust and FMIC so this would constitute slightly higher boost than normal right?

fun, cheap little mod

Link to comment
Share on other sites

Finally got around to doing this today. Car feels to pull a but harder when coming out of a corner in second. Haven't had the chance to take it for a big hit yet.

If it's not done correctly it will only boost to ~5psi correct? On my stock 34 boost gauge she sits a little over halfway to +1 which would be around 0.8 bar is that right? Only mods are full 3.5in turbo back exhaust and FMIC so this would constitute slightly higher boost than normal right?

fun, cheap little mod

If it's not done correctly it could go to infinite boost or 5psi.

Personally, I would not trust the factory gauge - whilst the boost sensor reads accurately, it's impossible to get an accurate measure on the actual boost you're reading. If you are hitting 0.8 bar that's 11.6psi - which may be on the high-side.

With a 3" exhaust & FMIC - without this modification - I was hitting around 8-8.5psi through the mid-range. Even with a 3.5" exhaust, I wouldn't have thought you'd be hitting 11.6psi - but maybe it is. I ended up fitting a 10psi R32 actuator to get a steady 10psi (0.68 bar) - which is safe on the factory turbo. I quickly hit R&R when I let the factory boost solenoid connected as well so this was dropped.

Either way - yeah, maybe temporarily (or permanently) drop an aftermarket boost gauge on there, I'd be surprised you not hitting R&R if you are hitting 11.6 psi..

Link to comment
Share on other sites

If it's not done correctly it could go to infinite boost or 5psi.

Personally, I would not trust the factory gauge - whilst the boost sensor reads accurately, it's impossible to get an accurate measure on the actual boost you're reading. If you are hitting 0.8 bar that's 11.6psi - which may be on the high-side.

With a 3" exhaust & FMIC - without this modification - I was hitting around 8-8.5psi through the mid-range. Even with a 3.5" exhaust, I wouldn't have thought you'd be hitting 11.6psi - but maybe it is. I ended up fitting a 10psi R32 actuator to get a steady 10psi (0.68 bar) - which is safe on the factory turbo. I quickly hit R&R when I let the factory boost solenoid connected as well so this was dropped.

Either way - yeah, maybe temporarily (or permanently) drop an aftermarket boost gauge on there, I'd be surprised you not hitting R&R if you are hitting 11.6 psi..

Nah definitely not getting infinite boost as it peaked just over that halfway mark on the gauge as I mentioned. Yeah I know the factory gauge is pretty dodge - I wouldn't mind a proper accurate gauge, I think it would be wise if I eventually get a nistune. Do you know if it's possible to just change out the factory boost gauge and leave the others (apart from looking a bit meh)?

I guess the question is - those who have done this mod and are still using the factory R34 boost gauge, where does ~5psi sit? Pretty sure I have done the mod correctly....it doesn't look like rocket science.

erm...whats R&R :blush:

Link to comment
Share on other sites

Got it, thanks.

It feels fine but will get more of an idea of the changes when I take it on my usual circuit.

I know it has been asked already but is there any longevity problems with this mod? I'm sure there are people that have been running it for a number of years now..

Link to comment
Share on other sites

  • 2 weeks later...

Got it, thanks.

It feels fine but will get more of an idea of the changes when I take it on my usual circuit.

I know it has been asked already but is there any longevity problems with this mod? I'm sure there are people that have been running it for a number of years now..

Runing this mod for 1 1/2 years, daily no problem.

Link to comment
Share on other sites

Runing this mod for 1 1/2 years, daily no problem.

Yep all good for me too, car seems to have a little more punch around the 3k rpm mark but no change higher in the rev range. Induction noise is almost bordering on annoying down low.

Would recommend this to everyone with stockish setups.

Link to comment
Share on other sites

  • 1 month later...

Hi All,

I did this mod on my stock 96' S2R33 & now she wont rev past 2500rpm.

I freaked out (cause I just got the car), &put it back to original(re joined the wire),

But still only reving to 2500rpm...

Please help, I'm new to skylines..

What could be the problem??

Link to comment
Share on other sites

Did this today, took it for a drive.

Works perfect and feels awesome!

Just for clarification. Is this safe to run on a stock 33 with just a pod filter.

Cheers

Colin

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • from my limited BMW experience: - they burn oil WTF (B48 FTW 170kW engine) - dump oil every 5,000km and you'll be ok.. until it drops a bearing and rebuild time. replace engine with B58
    • I would avoid the AWD motor in a RWD using a modified RWD sump and pickup. The way the pick up is positioned, you'll have oil pick up issues on hard acceleration on a track around bends. Even with a baffled, gated sump. I suppose if you don't race on a track and it's used for straight line activities or street use you might be ok.
    • They absolutely are, but the thing is, if you're only exposed to these circuits for a while, what I normally think is good driving suddenly isn't so much. I was a pussy at the Nurburgring (GP) entering corners at 180kph - the difference in the balance of the car suddenly becomes so much more pronounced and I'm still a bit regarded at left-foot braking - something I now practice on my commute. So the (dream) plan with the E90 is to make it a 325i Cup car. Whether I get there or not is another matter. In my mind the simplicity of having the NA variant and cost made it a bit more appealing. Plus, like mentioned above, I'm actually too much of a pussy for big power. Of course I f**ked up by not researching enough on the N53 vs N52, the latter being more robust without the DI system.  Suspension-wise on the BMW, and I've been reading the technical requirements for the 325i cup, basically everything except struts has to be standard - bushes are free. I figure you get about 5-10mm adjustment with the rear camber bolts which should translate to 0.5- 1.5 degrees of adjustment. So with coilovers, lowered at 30/40mm I expect I can dial out some of the camber from a drop and attain -1.5 to -2. If necessary, I could get the same effect as the M3 arms with some offset bushes. There is a limitation on ARB width to qualify, although I absolutely want to get either M3 ARBs (can't say sway incase I upset GTSBoy) or the H&R ones - both of these are the cheapest options. Like mentioned, M3 arms are on the way and I should have them fitted within the next week. How are the BC Racing coilovers btw? Reviews are mixed but I think for me they would be fine; a friend of mine uses them on his R34 for track driving and has nothing bad to say. I'm looking at these or the ST coilovers (German brand, new to me) as prescriped the in Cup spec sheet. They're both similarly priced and offer camber adjustment. It's fine but it really upsets my OCD. I've got a couple of options for dialing out the rear camber and keeping my ill-fitting wheels: raise the rear a little bit, say 5mm, that should permit -2.5 camber or drop the front to restore that slight bias of more negative camber up front (not optimal with the roads here). The next alignment won't be until at least next year and I really need to rebuild the rear subframe. For now, I'm not using it at all on the streets except occasional blasts through the German countryside. I was covering about 10k kms p/year in Japan, I expect this to now be about 3-4k. You could say buy better sized wheels, and yes, I should have. But the wheels came from the Z and price of good wheels is just insane now. Again, a couple of options: get a new set (I want 17" RPF1s) or buy two used 9.5J TEs, both are about the same price excluding shipping. 
    • by rotating the motor i mean to dismount the plate on the motor and mount it different 
    • Sorry I meant to say, Is that $3,500 landed or is that just the sticker price in Japan? 
×
×
  • Create New...