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Ok so I know we have a lot of information out there but i'm noticing a big gap of information I can't get filled no matter how far and wide I read. Don't think i'm slacking because I literally just read the whole 89 page Guilt Toy on E85 thread in search of answers.

What I want to do is extend a bit beyond and add to the great guide: http://nissanskyline.6te.net/tuning_GTS25T.htm which is great for stage one but beyond that becomes a bit wishy washy and makes no mention of E85

It lacks a bunch of information that i'm sure other people will also spend forever hunting for so this thread serves to find out that information and collate it all in this location.

This is basically inspired from the fact that I want to go up in rwkw but i've no idea what's entailed and many people give differing answers.

So I bought the car with stage one done Already:

  1. Exhaust (varies in size from 80mm - 100mm)
  2. Intake (not pod, just modified stock box)
  3. FMIC
  4. Bleed valve boost increase to 15psi / 1bar
  5. Power FC
  6. Exedy heavy Duty Cluch
  7. Walbro GSS 342 fuel pump (22lph (will need to come out for E85)

Also came with start of stage 2:

  1. GCG Highflow turbo

The car's best dyno was 238.9rwkw (Dyno Dynamics at Ace Workshop)

And now we move into the unknown territory where I try to find out the truths behind different modifications.

What rwkw or other benefits do these yield?

  1. Catch Can (Haven't really seen any concrete information on it's usefulness)
  2. Fuel pressure regulator (Does this yield results regardless or is this circumstantial? I have heard something about the fuel system pressure triangle (pump, injector, regulator) and they work in synergy somehow)
  3. AFM (Does this yield a power improvement?) (Are there advantages to cutting out the AFM with an ECU that doesn't require one?)
  4. Injectors (this could use some clarification in terms of what rwkw limits they are good to in terms of 98 and E85)
  5. Fuel pump (Why is the Bosch 044 just the pump to go for? just seems overpriced compared to competitors)
  6. Stock flywheel limit?
  7. Cam gears?
  8. Front facing plenum (So much controversy over this one, one person says they love theirs and another person says they wish they never did it)

Another thing I have not really been able to understand is the limits of an item such as my GCG highflow. The site says I can expect 240-250rwkw from it at 18-20psi but i've got basically 240 at 15psi. And when I throw E85 into the mix does this completely annul those figures or is that still the limit of the turbo?

I asked the question "How much power can I get from the GCG highflow" the response was "How long is a piece of string" so I want to understand that a bit better. Does that mean, the more supporting mods I put on the more it will make or does that mean more along the lines of how far can you push it until it will break, or something else entirely?

What i'd love from this really is to build a step by step guide that helps people get the most economical way to gain power. Power gain vs Price and be relevant to pre-requisite modifications.

I kind of ran out of steam, let's start there and try and make this a really good bit of info for future searchers :)

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https://www.sau.com.au/forums/topic/425779-skyline-tuning-guide-expansion/
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Seriously.....all this HAS been covered before, many times, in many places.

You have just confirmed the problem. Many places you must go to get all the answers for a very linear topic. Because there are so many places there is so much wasted duplication. No single source people can go to for reference. Having to read 89 pages of a single thread in hope that you find the information you need amongst the colossal masses of posts. Most of which are useless but you still have to pore over about a thousand responses in a single thread in hope to find and answer to a question that HAS been answered before but not conveniently compiled. Also having a more centralised and complete source of information allows conflicting views to come together and be 'hashed out'

Am I really wasting my time? No one sees my point?

i agree.. sometimes its frustrating having to shift through 100 threads and then you are still unsure and unable to go back to read something you read 2 hours ago because you have lost the thread.

its always good to have a complete howto, it can't hurt right ?

  1. Catch Can (Haven't really seen any concrete information on it's usefulness)
  2. Fuel pressure regulator (Does this yield results regardless or is this circumstantial? I have heard something about the fuel system pressure triangle (pump, injector, regulator) and they work in synergy somehow)
  3. AFM (Does this yield a power improvement?) (Are there advantages to cutting out the AFM with an ECU that doesn't require one?)
  4. Injectors (this could use some clarification in terms of what rwkw limits they are good to in terms of 98 and E85)
  5. Fuel pump (Why is the Bosch 044 just the pump to go for? just seems overpriced compared to competitors)
  6. Stock flywheel limit?
  7. Cam gears?
  8. Front facing plenum (So much controversy over this one, one person says they love theirs and another person says they wish they never did it)

1. You wont gain performance from this

2. You wont gain performance from this, unless your injectors are maxed, in which case its better to buy the right injectors

3. Again, no performance gain unless yours is maxed, it shouldnt be at that power level

4. Dont remember the stock injector limit

5. Pump should be fine

6. Stock flywheel should be fine. I have an NPC lightweight flywheel, which I think is better, but its not THAT different

7. Potential for minor performance gains if your willing to play around

8. Devided.... I have one, but I got it as part of a deal and its mainly cosmetic on my car. I dont think performance is any different to before

1: A catch can can improve the efficiency of your cooler by making sure the insulating blowby oil doesn't coat the inside. The oil can also cause detonation if you are pushing the limits.

2: Higher pressure at the injector usually improves the spray pattern which can improve the burn resulting in more economy and power. Don't go too high, most fuel pumps will stop flowing much over 80psi.

3: A larger AFM body could help flow by allowing more air to pass, but you will lose AFM resolution. Best bet is to ditch the AFM fist chance you get and go MAP sensor.

4: It's very hard to judge power output from injector size as everyone runs different pressure, afr's and engine setups. Torque increases demand more fuel even if power doesn't rise.

5: 044's are an old noisy design, there are much better options out there now days.

6: Stock is good if it's flat.

7: Cam gears allow you to tune the camshafts for response or power by advancing or retarding them slightly. It can be time consuming for little gain sometimes.

8: FFP's can shorten the cooler piping, help fit larger injectors and rail and shorten runners to add top end power (usually at the expense of midrange) Unless they have been thoroughly tested for flow you may go backwards or even lean out a cylinder.

As you see, there is no correct answer for everyone, it depends what you want from your setup. My suggestion is to do one mod at a time and analyse the results as most modifications have consequences. (like increased noise, drivability, reliability etc.)

On the topic of e85, you should gain around 40kw at that power level, and a good amount more torque. The only real down side to ethanol is your fuel range will be 2/3 it was, and winter cold starts will chew through the fuel.

You have just confirmed the problem. Many places you must go to get all the answers for a very linear topic. Because there are so many places there is so much wasted duplication. No single source people can go to for reference. Having to read 89 pages of a single thread in hope that you find the information you need amongst the colossal masses of posts. Most of which are useless but you still have to pore over about a thousand responses in a single thread in hope to find and answer to a question that HAS been answered before but not conveniently compiled. Also having a more centralised and complete source of information allows conflicting views to come together and be 'hashed out'

Am I really wasting my time? No one sees my point?

I have been doing alot of research on here myself and I can see you point for sure. It can be frustrating but I think a positive I have found from having to do all the reading is you get to learn who on this forum really knows what they're talking about and who is just repeating information that they've heard somewhere. That becomes pretty important especially if you have single point of reference which you would like - then you would want to make sure you actually have the correct information in there. Also there is always going to be different opinions even amongst the most knowlegeable blokes here 'different ways to skin a cat' so to speak. Good idea, just my 2c.

You have just confirmed the problem. Many places you must go to get all the answers for a very linear topic. Because there are so many places there is so much wasted duplication. No single source people can go to for reference. Having to read 89 pages of a single thread in hope that you find the information you need amongst the colossal masses of posts. Most of which are useless but you still have to pore over about a thousand responses in a single thread in hope to find and answer to a question that HAS been answered before but not conveniently compiled. Also having a more centralised and complete source of information allows conflicting views to come together and be 'hashed out'

Am I really wasting my time? No one sees my point?

Well, in my opinion, yes. Especially seeing as most of what you wanted to work on in this thread has nothing to do with making power directly (like catch cans) and is only done because you end up having to to control oil. Refer to the comment from people above who could actually be bothered writing responses to your points.

Furthermore, this is not the first "summary wrap up thread attempted". If you were to actually go to the effort of creating a decent one, it would be better to start from a position of knowing what is right and wrong instead of putting up a bunch of topics, some of which are unimportant. Example - limitation of stock flywheel. Of course there's no limitation. It's a lump of steel. There are reasons to want to change it, but only to gain benefits, not to stop you from banging into a brick wall power wise.

Ok some for, some against, to be expected. Thanks for all the input so far. This thread is going to be a mix of questions for my personal car and more general information but I think the result of both will be useful to people who will end up in my position.

I seem to be gleaning that maybe a catch can is less important for someone running E85 because it has so much detonation headroom already. The catch can question just came up amongst this because my blowby hose is cracked and I was looking at replacing the hose or installing a catch can setup.

One small obscure piece of information I came across was the clashing space requirements of plenum/injectors/rail. This isn't really made clear in a lot of places. I think seeing as the FFP is going to make most cars that much more defect-able it's not worth the maybe gains, despite how cool I personally think they look. However that brings to life new questions, which injectors will and won't fit under the stock plenum and of those that will fit under the plenum which will fit the stock rail or not. Is there a way to determine this or is it more a case of find someone who's done it before or buy and hope?

Is a fuel pressure regulator legal in VIC?

My fuel pump says it's not E85 suitable Walbro GSS342, I can't find any information WHY anywhere. Does anyone know if that's just because it generally wouldn't flow enough or there are some other factors? Because I did read a couple of posts somewhere where someone was tossing up doing dual in-tank GSS342's for E85 which makes me think it's just because a single GSS342 wouldn't flow enough.

Some of the question might seem a bit off like the flywheel question. I haven't heard of a single person changing their flywheel but I ask because it's mentioned in the original tuning guide.

Just like Changing the head gasket at 1.2bar, I've never heard of anyone doing that. Is it just something that is done and not mentioned or...?

Is it legal to remove your AFM? I'm guessing no especially in VIC.

What modifications ARE legal to allow the running of E85 in a car in VIC?

How do I go about collating all this information into my first post? Can't edit it.

My fuel pump says it's not E85 suitable Walbro GSS342, I can't find any information WHY anywhere. Does anyone know if that's just because it generally wouldn't flow enough or there are some other factors? Because I did read a couple of posts somewhere where someone was tossing up doing dual in-tank GSS342's for E85 which makes me think it's just because a single GSS342 wouldn't flow enough.

The alcohol in the fuel eats away at the insides of your fuel pump. So technically yes you can use it with E85, but definitely not recommended for extended periods of time.

Anything with "E85" "Ethanol" or similar is obviously designed with different internals that are not affected by ethanol fuels, anything without those key words is no designed for use with alcoholic fuels and will degrade the internals of the pump, eventually causing lack of fuel and leaning the engine out (worst case scenario)

Pretty straightforward really.

There have been long term e85 tests on Walbro 255's with no issues, but then the 400L fails within a few months. It's the reason they released the e85 version.

I have been running my pair of Walbro 255's for nearly 4 years on e85, daily driven, without a problem so you would be fine.

Remember all fuel system components are designed ethanol safe these days as unleaded is 10% ethanol anyway.

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