Thoughts On R25 On Eflex Vs The Rb30 Route .

[discopotato03]

I never intended to use a GTRS on an RB30 , as for on an RB25 the only thing holding up the show is the RSs 0.64 AR turbine housing . HKS really should have had a 0.86 AR version of that turbine housing made because I reckon you'd get closer to 0.68 2835 type performance out of them . I did once look at the turbine maps for the GT28 NS111 turbine in 0.86 housing flow rates and compared it to GT30 ones in various ARs .

Anyway an RB30 really needs a GT30 based turbo and probably at least a 0.82 turbine housing on it . I still have my 0.82 GT3076R 52T on ice and if I ever went RB30 I'd use that .

At this stage I'd like to try E85 or similar on my 25 and I think the ViPec or Link G4 plug in sounds good . Goes into factory ECU box so a bit more stealth at a glance . I have to read more of Guilt Toys experiences with these and another thread I found here of when these plugs ins first came on the market .

I need to speak to Scotty at Insight because I know he has done flex fueled Evos with V88 computers and seems to have the flex thing worked out .

I think PFCs are alright for what they are but later faster boxes seem to do all the crunching in real time so have a bit finer hold on the engine electrics .

I think these have an auto tune feature and it would be real good if it was tuned on E85 and then the auto function could make changes to an ethanol percentage correction table .

Also its not impossible to look at RB30s later but a flexed 25 may well be all I need and that gets around the engine number and insurance dramas .

Anyway SK Garys sold on E85 and will get to see him soon to talk options .

Yes I will need a better intercooler and no I don't want non std plumbing in the engine bay so that means something like those rare Trust turn flow intercoolers . I did see a similar kind of thing locally made though it had a bar and plate core which I won't have . Someone here makes another single sided XR6 upgrade cooler and that could be an alternative too .

So basically cooler computer sensor and tune .

A .

[TiTAN]

I think these have an auto tune feature and it would be real good if it was tuned on E85 and then the auto function could make changes to an ethanol percentage correction table .

A .

they do but not in the way you are thinking, it requires a dyno and steady loading to work out fuel map values only.

[discopotato03]

Yes I gathered that .

[Lithium]

Anyway an RB30 really needs a GT30 based turbo and probably at least a 0.82 turbine housing on it . I still have my 0.82 GT3076R 52T on ice and if I ever went RB30 I'd use that .

No way, GT3076R (let alone a 52T one) on an RB30 - I honestly don't know how anyone who have been paying attention could think that is a good idea. Things have progressed so far in turbo/tuning technology, and so many experiences have been shared yet in some places they seem to have gone around in circles.

Nonetheless, I have myself thought that an RB25 with a GT-RS with a flexfuel setup would be something of a fun thing if one wanted to make a cheap (!) close to stock type setup that went really well everywhere - of the variations discussed it seems by far to be the most logical idea.

[discopotato03]

Lith I know you don't believe it but no one will ever run any form of GT3076R to its full potential without the largest available turbine housing , the jump in exhaust flow is considerable 0.82 to 1.06 and if either side of the housing can handle the gas flow rates volumetric efficiency has to climb with it .

A lot of people seem to think 1.06AR turbine housings are GT3582R territory when they were in fact designed for GT30 turbine wheels . The reason you get them on 82R turbos was because there is nothing else available (speaking Garrett here) , they just copied what HKS did with GT3240Rs (cropped turbine 54T GT3582R) but with non cropped GT35 turbines .

I personally think GTX wheels are a bit of a crock and blind Freddy knows they need larger bulkier compressor housings . Not going to happen . Also aftermarket wheels like HTAs often work better .

Anyhow all that aside the 76R 52T I own and it would make more than enough power for any road only car IMO .

A .

[scotty nm35]

I agree, the GTX wheels are a crock if you only plan on running 20psi on a stock bottom end but how many results have you seen that actually max out the compressor? As you say, not many people interested in running the 1.06 rear either so it probably won't happen on the GTX3076 any time soon. I know I am too scared. lol.

[Lithium]

Lith I know you don't believe it but no one will ever run any form of GT3076R to its full potential without the largest available turbine housing , the jump in exhaust flow is considerable 0.82 to 1.06 and if either side of the housing can handle the gas flow rates volumetric efficiency has to climb with it .

A lot of people seem to think 1.06AR turbine housings are GT3582R territory when they were in fact designed for GT30 turbine wheels . The reason you get them on 82R turbos was because there is nothing else available (speaking Garrett here) , they just copied what HKS did with GT3240Rs (cropped turbine 54T GT3582R) but with non cropped GT35 turbines .

There was no talk of 1.06 housings, or running the GT3076R to its potential. The compressor will be past it's best as is, don't put words in my mouth and then correct me on it. Not debate from me that the 1.06 would significantly improve the flow but theory or history of the GT30/GT35 turbine housings vs wheel combinations aside proof in the pudding for some time now that the larger GT35 turbine proves to make people and engines happier than battling with the GT30 based turbos to try and get the best power/response combination together in that grey zone - especially on a 3litre. The 1.06 hotside on a GT30 will make something that starts feeling like a limp version of a small housing GT3582R, imho.

I personally think GTX wheels are a bit of a crock and blind Freddy knows they need larger bulkier compressor housings . Not going to happen . Also aftermarket wheels like HTAs often work better .

Totally agree.

[Dose Pipe Sutututu]

Interesting thread, gives me more reason to save some more coin for a GT3582.. still waiting for that tax return (with 2x redundancies hehe)

[AngryRB]

i dont know why your bagging the gtx3076, have you actually driven one? if you were in mine and felt the nastiness at 4000rpm you would change your mind, the gt3076 may be at most upto 500rpm sooner response but the gtx really doesnt deserve the "bit of a crock" comment, more like saying its less desirable if you need perfect response.. cause when it comes on it fries tyres like a V8 and thats not a bit of a crock....

experience it before you judge it i think.. mine is nothing like that comment ... i absolutely love that 4000rpm pissed off gtx

Edited August 17, 2012 by SliverS2

[discopotato03]

I'm not having a shot at anyone who bought a GTX3076R I just think the reasons behind their release were market based . Bit morer bit blinger bit laggier .

That aside I spoke to SK this afternoon and he thinks I should give Eflex a whirl as it is meaning with the R34GTt SMIC . It would be an interesting experiment providing the boost was kept sane meaning possibly one bar . He also found another Eflex servo not far from me which is a bonus .

I'm tempted to go grab a small amount in fuel containers and have a play with the datalogit and Tech Edge . I don't do much tuning and I need to see if I can globally up my fuel table by 25-30% and see what happens . If I can make it run acceptably I can get it to Scotty at Insight and have him tune it properly .

Better intercoolers can come later and a slightly bigger turbo if I think it needs it .

SK really likes Eflex and their finding is that it actually works out cheaper once tuned than Ultimate PULP . They reckon you use about a third more Eflex by volume so if you use $1 a litre as the cost basis and add 1/3 $1.33/L looks better than $1.46 plus for Ultimate .

So initially should owe me a tune and see what happens , I'd expect it to go better everywhere though it will show up any limitations moreso than it does now .

Hope it smells as good as United E85 , cheers A .

[zebra]

Tbh I doubt you will gain anything but just swapping over, maybe if you are knock limited now, but I doubt you are given current boost levels

The gains will come with more boost

I'm not sure why you are not going for a justjap turn flow intercooler, and instead are hunting for a 2nd hand trust item

As for bar and plate vs tube and fin.....a moot argument if you ask me, it's a street car and given 99% of us are running bar and plate and so are 99% of Motorsport guys...

But your choice in the end

But me

Cheap cooler kit, wind the boost in on e85 and just enjoy it

You won't notice the difference between a made in china cooler vs an over priced jap tube and fin jobbie

[AngryRB]

if doing it again i would go gt3076 with 0.63rear external, but i dont dislike the gtx, upto 3500rpm its respectable, on 4000rpm its a violent weapon and fries tires ... third is scary.. pulls and never runs out of steam.. must be experienced...

to share my experience ( last 2 weeks) i have seen 400km on about 75L ( 17L/100km compared to 11-12/L on 98) of Eflex fuel and ill admit my tune is probably on the rich side to account for variation in the concentration of Ethanol in the fuel which i was informed and have accepted...

the driving was a mix of highway and some squirts.. and really i dont care.. i have the power and i have the servo's reasonably close.. the fact that it has the power in reserve makes it ok to me with it being a weekend mostly vehicle..

so i dont think you should count on it being better than that.. cause you might be dissapointed..

it smells awesome and wont dissapoint you though .. my performance increase on my car was all ignition timing. i didnt increase boost on mine except in the midrange apart from that it was all timing.. 6 degrees extra was 40kw from 3500rpm to redline.. no extra boost needed... so you will love it. and its all extra safety... which makes it that much better...liquid gold i say ...

Edited August 17, 2012 by SliverS2

[zebra]

Re-read what I said

If you are not knock limited then there will be no gains

V8 super cars and NASCAR are a perfect example of this

Supertaxi's lost 10 or so horsepower going from pulp to e85 NASCAR ran 102 octane Sunoco fuel and lost a bit going over to e85

It burns slower which is why it doesn't pink as easily but in turn that means it has less energy

So just adjusting the fuel side of an engine map you will go backwards without more timing advance

[AngryRB]

every turbo car is knock limited isnt it?? or wouldnt they all just run maximum advance all the time??

mine managed 6 extra degrees advance and that made 40kw so thats proof...

i dont think were talking about v8's here , were talking bout disco potato's GTRS turbo'd RB25 so he will pick up kw's everywhere.. or have i read it wrong??

it has less energy but you use more, its heavy and can take more timing and more boost so it works out better ... i dont think it needs more timing but will put out more with more timing.

bottem line, yes you need extra timing ... and if extra boost then you'll gain even more.. but with just timing you will still gain alot

Edited August 17, 2012 by SliverS2

[zebra]

Nope, mine isn't

Plus engines rarely make max power with max timing (if you aren't knock limited)

You made more power because you can run more timing because your car was limited by fuel

It's not proof at all

Go run 5 psi with a small turbo with a huge exhaust housing on an engine with 7:1 compand tune on both e85 and 98 and see how it goes

Every engine is different

[AngryRB]

i think ive lost what we were talking bout here... i thought we were talking bout wether an rb25 with GTRS turbo would kick ass on E85 and i was saying he would... and wouldnt need more boost and that with extra timing he'd gain even..

i know v8's dont really gain unless they are knock limited, and normal cars dont either ...

but his car will gain cause it would only be able to run so much timing with that smallish turbo wouldnt it??? and also only so much boost before it got too hot from backpressure???

so the answer is yes.. more power from "JUST extra timing and you like more power from EXTRA boost" ..i think thats about right isnt it?

[discopotato03]

Well these are my theories but yet to try my combination out .

Bit better exhaust/cat/front/dump/turbo/IC/head/cams/MAF/filter element . Should be a bit less restricted everywhere than standard so should get more in and out than Nissan did .

I think the value in high ethanol content fuel is twofold . Firstly you're injecting 1/4 to 1/3 more liquid and the greater volume has more capacity to cool the charge air - evaporative cooling . Secondly yes it is a slower burning fuel so better control of the combustion event should be possible . Sort of start the fire earlier and time the pressure rise so it occurs at the most advantageous point . People say you can run leanish mixtures at times with pumpE85 and not get detonation as easily as pump98 sometimes does . There are pros and cons burning a lower heat value fuel because its generally the heat and pressure that causes detonation in the first place . The balancing act is getting enough heat to develop the cylinder pressure to make good power and some peoples theory is if you don't get enough heat you add more fuel .

With too much heat and or pressure pump ULP wants to detonate and you have to find ways to manage the heat and sometimes pressure to limit detonation . The simplest way is to retart the spark ignition timing (fire point) so that combustion event starts when the pistons are further past TDC on the power stroke than you'd like . The combustion pressure/temperature will be lower and below the detonation threshold - if the timings retarded enough .

I like Corky Bells ideas and I think he got it right when he said the greatest dramas with forced induced engines are thermal ones . Basically you are taking a given engine and increasing its power output by generating higher cylinder pressure - and heat .

There are lots of ways to control temperature and generally it starts with air or charge temperatures . Cold air intakes intercoolers maybe some insulation . Evapotarive cooling is significant and the more the better IMO . Cool air is more dense and contains a greater weigh of oxygen but I reckon the important thing is that cooler charge leads to lower combustion temps and thats the thermal management part of reducing detonation . Air fuel ratios play a big part in combustion temperatures and if you get cooler burning and a detonation resistant mix it has to be all good .

All of this is mainly an advantage in an engine that wants to detonate at or at less than the optimal charge firing point and since detonation is destructive you have to retard the timing to avoid it . Most people know that advancing the ignition timing beyond the point that best torque occurs is pretty pointless so why go there . My feeling is that this "wobble" thing people reported when they first started tuning seriously with E85 may have been because the combustion was srarted with the piston and rod too close to TDC , and the thermal pressure rise from the burning charge was trying to compress the piston and rod because the crank pin wasn't far enough past vertical or TDC to act as a lever .

In my case I need a tune anyway and my fuel system should cope - 740s and a GTR33 pump . I'm getting ~ 400-420 to the tank on Ultimate and this thing is not in the best state of tune but it is livable . I want to give Eflex a go because its about the closest thing you can get at the pump to race fuel and its a way of getting around the emissions dramas as well . I'd prefer to change to a better fuel while this car is in a pretty mild state of tune because it should open doors later if I want more performance out of it .

Like when my old dinosaur Subaru changed from effectively FrWD to AWD this is a toe in the water and if it works out out well then the Evo may get it as well . We know AWD is generally all good and I expect the Eflexto have its advantages as well . If the running costs are same or cheaper I can't argue with that either .

Gotta run , cheers A .

[zebra]

Lol my late night ramblings

[wolverine]

Disco, buy a cooling pro or a Blitz turn flow and be done with it they bolt up to factory piping and you can get it tuned once with all the fruit you need to get the best result.

[jet_r31]

Tbh I doubt you will gain anything but just swapping over, maybe if you are knock limited now, but I doubt you are given current boost levels

The gains will come with more boost

I'm not sure why you are not going for a justjap turn flow intercooler, and instead are hunting for a 2nd hand trust item

As for bar and plate vs tube and fin.....a moot argument if you ask me, it's a street car and given 99% of us are running bar and plate and so are 99% of Motorsport guys...

But your choice in the end

But me

Cheap cooler kit, wind the boost in on e85 and just enjoy it

You won't notice the difference between a made in china cooler vs an over priced jap tube and fin jobbie

Agree 200 percent re intercoolers...

Edited August 18, 2012 by jet_r31