Jump to content
SAU Community

Recommended Posts

  • Replies 214
  • Created
  • Last Reply

Top Posters In This Topic

True, but if you do a B4 engine swap then you'll have a nice low-end and a free top end, but with a crap mid-range.

Unless you're willing to spend the time and money setting up and tuning your twin turbo setup properly, you're going to hit a nasty flatspot at the point the two turbos change over.

Even if you do, you add a lot of complexity to your setup. If something goes wrong, you're going to have a hell of a job trying to figure out what's failed.

In the end, I'd much rather a EJ20 with a 2.2 stroker kit and a well-matched single turbo. Not as inherently weak as the EJ25 that everyone else has mentioned, but still more torque and better flow characteristics than the stock setup.

Agree with you about the sequential turbos. The B4 has the well-documented "Vally of Death". Check out a typical B4 dyno plot to see what I mean. Sequentials are bloody hard to set up and quite often when people do some serious mods they are the first thing that goes in the bin. The sequentials on the S6 RX-7 are a good example of this.

I think Subaru agree as well as they chose to dump the twins and go to a single, well-sized twin-scroll turbo with the GT.

If I were building a really tough engine I'd go for a 2.2 but rather than a stroked 2 litre I'd go for the 2.2 fitted to the US-spec Legacy Turbo. This thing is basically the same block as fitted to the 22B so it's fully closed-deck with very strong internals and it doesn't have the rod ratio problems which limit revs as the stroked 2L 2.2 setup does. Interesting is that these engines have got piston oil squirters but these were deleted for the 22B.

...Ben

A mate owns a B4, has had a few things done like ecu remap to try and minimize the flat spot. Have looked at the dyno charts and it is still there - just more power all round. Funny thing is in stock form he had to get the engine rebuilt after just 10,000 k's - big end bearing. The guy at Subaru docklands said he was under the impression that they had not been de-tuned very well for our fuel. Also had to get the gearbox rebuilt after smashing a syncro not too long after that.

Other mate has a 98 WRX - 40,000 k's following a decent track day out at winton saw a gudgeon pin fail - out came the engine for a full rebuild, also got the gearbox and clutch done at the same time. He does drive it pretty hard, and John Bowe gave it a good fang around the track that day - but once again not good news for suby warranty claims dept.

Still love the rexies, but I am way happier with the over engineered gtr in the driveway.

so lets see here...

you want...

no lag

good off boost driveability

ability to run a large turbo

no gearbox problems

not too expensive?

hmmmm..

rb30det seems the way to go.

it's the answer to every performance question on this forum.

Q)how do I get more power from my R32 gtst?

A)RB30det

Q)How do I beat a (insert any performance car here)

A)RB30det.

Q)How do I have heaps of power without more lag?

A)RB30det.

Q)Will my R33 gtst beat a wrx?

A)with an RB30det it will.

Q)How do we end this thread?

A) RB30det.

Q)How do I get an RB30det?

A)RB30det.. I mean http://www.skylinesaustralia.com/forums/sh...ead.php?t=15420

I like "but in the wet" comments.. how often does it really rain? well where I am sitting maybe 1 in 10 days.. rest of the time the road is pretty much dry and its never an issue. And when it is raining, its not that hard to drive a tad more relaxed. If I had a rex, I woudln't be pushing it in the wet, even if it did handle like it was dry.

Maybe why WRX are so much more popular in melbourne and sydney than here :rofl:

Agree with you about the sequential turbos. The B4 has the well-documented "Vally of Death". Check out a typical B4 dyno plot to see what I mean. Sequentials are bloody hard to set up and quite often when people do some serious mods they are the first thing that goes in the bin. The sequentials on the S6 RX-7 are a good example of this.

I'm not sure what the S6 RX-7's power delivery is like (hence why I said nothing) but I know that, with the tangled mess of pipes that it does use, when something breaks it's an adventure to try and figure out at which point you've had mechanical failure.

Having a single turbo is simpler, so its usually easier to setup and maintain and more reliable. Even if you're talking engines with parallel turbos (RB26, 2JZ come to mind) at a certain "seriousness point" they get ditched in favour of the big single.

While a part of this is increased flow, if you're going to cause major stress on a lot of components by pumping out a lot more power than the factory intended, its a lot easier to do it and keep it all together if there's only 1 of everything.

hmmmm..

rb30det seems the way to go.

it's the answer to every performance question on this forum.

Reminds me of this quote from The Simpsons:

Troy:  Now, turn to the next problem.  If you have three Pepsis and drink one, how much more refreshed are you?  You, the redhead in the Chicago school system?

Girl [her face appears picture-in-picture]:  Pepsi?

Troy:  Partial credit!

I like "but in the wet" comments.. how often does it really rain? well where I am sitting maybe 1 in 10 days.. rest of the time the road is pretty much dry and its never an issue. And when it is raining, its not that hard to drive a tad more relaxed. If I had a rex, I woudln't be pushing it in the wet, even if it did handle like it was dry.  

Maybe why WRX are so much more popular in melbourne and sydney than here :)

He says after the GC floods!

so lets see here...

you want...

no lag

good off boost driveability

ability to run a large turbo

no gearbox problems

not too expensive?

hmmmm..

rb30det seems the way to go.

it's the answer to every performance question on this forum.

Q)how do I get more power from my R32 gtst?  

A)RB30det

Q)How do I beat a (insert any performance car here)

A)RB30det.

Q)How do I have heaps of power without more lag?

A)RB30det.

Q)Will my R33 gtst beat a wrx?

A)with an RB30det it will.

Q)How do we end this thread?

A) RB30det.

Q)How do I get an RB30det?

A)RB30det.. I mean  http://www.skylinesaustralia.com/forums/sh...ead.php?t=15420

Q)How to get uncontrolable wheel spin in your manually equiped car?

A)RB30det

:):D:D

I'm not sure what the S6 RX-7's power delivery is like (hence why I said nothing) but I know that, with the tangled mess of pipes that it does use, when something breaks it's an adventure to try and figure out at which point you've had mechanical failure.

Having a single turbo is simpler, so its usually easier to setup and maintain and more reliable. Even if you're talking engines with parallel turbos (RB26, 2JZ come to mind) at a certain "seriousness point" they get ditched in favour of the big single.

While a part of this is increased flow, if you're going to cause major stress on a lot of components by pumping out a lot more power than the factory intended, its a lot easier to do it and keep it all together if there's only 1 of everything.

I hear that swapping to a single turbo from the sequential setup on the S6 RX7 saves you about 25 kg! Isn't the 2JZ sequential as well, while the 1JZ is parallel?

Q)How to get uncontrolable wheel spin in your manually equiped car?

A)RB30det

:):D:D

hahahahaha

you must be one of those poor disabled people who can't control pressure with their right foot.

:P :uh-huh:

therefore, what you need is an RB20det equiped car.

then you can flatten your foot to the floor all you want and wait for the power to come on..

hahahahah

*just waiting for Roy to come and yell at me..*

to those that saying rexies aren't laggy read this. This is about the sti. I found the standard rex to be a mild dose of what they are talking about with the sti.

I'm sure a VS v6 commodore would have more low end grunt (i.e. from 1000-3000rpm) than both the gtst and the wrx. I like the r33 because it has reasonable low end but the mid to top end is relly good. v6 commodore gets very rough. WRX no low end at all. Sti even worse. How did you like the way I managed to throw a commonhore in the mix?

http://autospeed.drive.com.au/cms/A_1463/a...?popularArticle

I've gotta agree the stock STi is a pretty hideous thing. Waiting for boost to come on does give you a good opportunity to make a few phone calls and catch up with paperwork though. :)

I guess that's what happens when you've gotta homologate a turbo for Group N. On the flip side you don't have to replace it until you're upping the ante quite a bit. An exhaust and a retune makes the world of difference to boost threshold but underneath it all it's a low-compression 2l engine which is always going to be sluggish off boost. I expect that an RB25 will feel much quicker in traffic.

...Ben

EDIT: Love the Commonwhore reference. My work ute has the V6 and it would make a great boat anchor. I read a thread on Street Commodores forum where they were trying to get a V6 into the 11s on a budget. Sounds like trying to polish a turd to me.

Hey Ben, i think they actually got that shitty vn commie into the 11's!

As for lag. my rex with the standard turbo and tb exhaust could reach 17 psi by 2500 rpm, is that laggy?

I've owned and driven numerous WRX's in very different states of tune, but I have never seen one make 17psi under 3000 rpm.

What mods do you have?

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

    • Bit of an update to this one. Having some issues on the dyno that held us back (boost spiking) and I want to pass some info over you guys and see what you think is wrong with my setup. The current readout on this dyno is 462rwkw on a low reading dyno so keep in mind it is a real world 500rwkw setup on a hub dyno. Don't read into the power figure too much as a sign of the issue. The short and curly of it is: 2.8 Litre Racepace build RB25 NEO N/A Head with VCT (internally standard however ) Borgwarner EFR 8474  Turbosmart 50mm Straight Gate + Mac valve 6Boost Manifold 4" dump to full 4" exhaust (nil restrictions) Wastegate plumbed back in and all angles in the exhaust system are acceptable and not too sharp. GFB SV52 BOV in cooler piping  Turbosmart BOV in EFR Housing   The issue we are having is it comes onto full boost for example at 4000rpm and spikes to 24/25psi, before dropping down to 17psi before slowly rising back up to the target boost of 23psi. It was extremely uncontrollable and the tuner actually had to ramp in boost progrssively with each 1000rpm on each boost setting we selected to try and reduce the amount of spiking. Sometimes we would see a drop of 10psi from the peak at the beginning of the run, to the low, until it took the next 500-1000rpm to stabilise back up to the target boost. The tuner is pretty confident that the straight gate is just a poorly designed product and leaks too much boost upon cracking the gate open and theres no way to fix it other than going to a poppet valve. He's also confient theres no ignition breakdown or floating valves. The fueling is extremely stable as well. Turbo speed is somewhere around the 109,000rpm area. The spanner in the works for me is that prior to this Borgwarner and StraightGate, the car was tuned on -5 twins at a diferent tuner, and he also had issues controlling the boost with it spiking around the same rpm range, so to me this sounds like the same issue and it can't be anything on the turbo side as this was all changed and I think the behaviour is extremely similar, if not the same. We also removed the mac valve and did a run on wastegate pressure and it still spiked and had the same behaviour. My thoughts on possibilities are: Boost Leak VCT Cam Gear isn't reliably activating consistently - (On this however, we did a run with the VCT disabled and the boost still spiked) Turbosmart BOV is not handling the boost? However this seems unlikely to not be able to handle 20psi. I have a couple of logs that I can't make sense of if anybody knows how to read them and can obtain further logs of other parameters if they are not enough, happy to pay for anyones time. The dyno readout with the power figure is the most recent last week. The other picture is from two weeks prior to that where we couldn't break 400kw (we removed the cat), however the issue of the boost control persisted. @Lithium @Piggaz @burn4005 @GTSBoy @discopotato03 I've tagged those that were quite active in recent pages here, no disrespect to those that know turbos well but I missed tagging. Cheers 
    • I recently purchased a 2018 Infiniti Q60, which has an SD card navigation map. I can see my system has options for real time traffic updates etc, and am wondering if there is something I can purchase to get this working? I can see there are at least updated maps for USA and Canada, but nothing for Australia. Surely Infiniti took changing road systems and city expansions into account when they decided to use an inbuilt navigation over Android Auto/Apple Car Play, or are we doomed to drive on streets that don't exist in the navigation system if you drive to a new area?
    • Luckily I didn't put in etch primer as I just found out it's not compatible with my body filler lol. Also just need to sand the panel anywhere between 150-400 grit so I'm in the clear there. It does say to not apply to soft old paint, I assume that means paint that is flaking, peeling,etc
    • @dbm7 and @GTSBoy thank you both very much! will give that a shot!
×
×
  • Create New...