Jump to content
SAU Community

Anyone Tried E85 With A Gtrs On Their Rb25 ?

discopotato03
 Share

Recommended Posts

discopotato03 Grand Master

discopotato03

Posted
Posted

I was just thinking about RB25s and GTRSs getting to around 250 odd RWKWs with supporting mods , and wondering if E85 would push a bit further to say 270 at the treads .

I suppose the limiting factor with a GTRS would be its 0.64 AR GT28 turbine housing , I'm wondering if E85 gives lower combustion temps and EGTs and if so can a bit more exhaust flow for a given turbine housing size .

Anyone using E85 and a GTRS in their Skyline ?

Cheers A .

scotty nm35 Grand Master

scotty nm35

Posted
Posted

I was running a simple stage 1 sierra bushed highflow, 250wkw at best limited by knock to around 18psi. With the e70 I could run much more boost and timing gaining 50wkw at 20psi. The compressor didnt have much more in it though. I assume the GTRS would be similar, possibly able to run more boost than my highflow.

I used to think it was best to max out a smaller turbo but I realized the pressure in the manifold was just too great and not allowing the cylinder to empty of exhaust properly. I guess this is where the extra torque comes from when going to a larger rear housing or turbo?

Lithium Grand Master

Lithium

Posted
Posted

Have thought about that, but it still feels mechanically mean - smallest I'd try that with would be a GT2835. Having said that, have been really interested to see how a stock turbo would go on the generally accepted "safe" boost level on E85 :ninja:

scotty nm35 Grand Master

scotty nm35

Posted
Posted

Im now running the stock M35 turbo, similar to an 0p6 34 wheel on Eflex atm on a temp tune. From 180kw on petrol to 225 on ethanol but it noses over as soon as I hit stall, 4000 rpm. Very responsive, too much so. I would hate to know the pressure in the exhaust manifold, it must be over 60psi.

ARTZ Grand Master

ARTZ

Posted
Posted

I though exactlty the same disco that cooler EGTs would somehow solve the isssue of haivng too much exhaust gas there in the first place..I was going to run my little turbo on e85, but as Scott said, trying to push that much gas through the rear end, although somewhat effective, is also self defeating and probably harmful to your system in general.

In my case I thinks it would be better to simply swap out the turbo and be able to make the same power on PULP, you may gain a little lag but the power would be more effective and better for your engine as a whole. Plus PULP is everywhere :)

joeyjoejoejuniorshabadoo Grand Master

joeyjoejoejuniorshabadoo

Posted
Posted

I would peg 280ish from a gtrs on e85

No one even dreamed 300+ was possible from a 2835 a couple of years back... So much so that when I did 320 some people called BS

Dan chin's old highflow hit 290rwkw on ethanol

You are looking at about 15% above what a given turbo is known to e capable of at th usual boost levels

scotty nm35 Grand Master

scotty nm35

Posted
Posted

I would peg 280ish from a gtrs on e85

No one even dreamed 300+ was possible from a 2835 a couple of years back... So much so that when I did 320 some people called BS

Dan chin's old highflow hit 290rwkw on ethanol

You are looking at about 15% above what a given turbo is known to e capable of at th usual boost levels

15% would be the gain with no extra boost. All depends what the tuner is comfortable with at the end of the day.

The stock turbo only made 1kw extra going from 17 to 18 psi but made another 100nm so even if the power drops off torque can still be improved. Not bad for a tiny ceramic wheel imo.

PM-R33 Grand Master

PM-R33

Posted
Posted

Man I would LOVE to give mine a hit on E85 and I definetely will as soon as we get it here. Would be interesting to see how far it can be pushed.

Would also make things a lot safer for me with the nitrous. Will hopefully have my car back on the dyno soon to see how what she is making these days with the gas.

Harey Veteran

Harey

Posted
Posted

So do we know the pressures in the manifold are dangerous using a 250rwkw turbo on 98 to make 270-280 on E85? I am running a very responsive hypergear turbo that makes ~250rwkw as well. My plan was to keep the responsiveness and add some more mid and top range by adding E85. Surely if I was to keep boost around 18psi it would be ok.

Whats the difference with SimonR32 running 25psi with a much larger turbo with an ethanol blend fuel?? Surely he would have quite high manifold pressures as well??

Is it the EGT's or the manifold pressure that we are mainly concerned with?

gotRICE? Veteran

gotRICE?

Posted
Posted

Having said that, have been really interested to see how a stock turbo would go on the generally accepted "safe" boost level on E85 :ninja:

Anyone you know that might be interested? I know someone that has some 555's "lying around" :)

ARTZ Grand Master

ARTZ

Posted
Posted

So do we know the pressures in the manifold are dangerous using a 250rwkw turbo on 98 to make 270-280 on E85? I am running a very responsive hypergear turbo that makes ~250rwkw as well. My plan was to keep the responsiveness and add some more mid and top range by adding E85. Surely if I was to keep boost around 18psi it would be ok.

Whats the difference with SimonR32 running 25psi with a much larger turbo with an ethanol blend fuel?? Surely he would have quite high manifold pressures as well??

Is it the EGT's or the manifold pressure that we are mainly concerned with?

EGTs and manifold pressure are basically related, responsive turbos usually have small rear housings to help spin your turbine wheel faster..

Problem is it will only flow so much.. More power = more exhaust gas..Try pumping too much exhaust gas through a small housing and it gets red hot.

It also backs up and gets forced back into your combustion chamber which is the last place you want spent exhaust gas when you are trying to pump fresh air in there..

Harey Veteran

Harey

Posted
Posted

EGTs and manifold pressure are basically related, responsive turbos usually have small rear housings to help spin your turbine wheel faster..

Problem is it will only flow so much.. More power = more exhaust gas..Try pumping too much exhaust gas through a small housing and it gets red hot.

It also backs up and gets forced back into your combustion chamber which is the last place you want spent exhaust gas when you are trying to pump fresh air in there..

Yes and then how does this change with E85 or other higher octane fuels? Is it not making more power out of the same amount of air? Or is it just enabling your engine to work the turbo harder without experiencing detonation?

My head is not working too well this afternoon!

scotty nm35 Grand Master

scotty nm35

Posted
Posted

EGTs and manifold pressure are basically related, responsive turbos usually have small rear housings to help spin your turbine wheel faster..

Problem is it will only flow so much.. More power = more exhaust gas..Try pumping too much exhaust gas through a small housing and it gets red hot.

It also backs up and gets forced back into your combustion chamber which is the last place you want spent exhaust gas when you are trying to pump fresh air in there..

Exactly, the gasses actually make their way back into the intake on valve overlap I have been told, thats why they carbon up. Not the best way to make powah, still it works. The ethanol just gives me a false sense of security. :)

scotty nm35 Grand Master

scotty nm35

Posted
Posted

Yes and then how does this change with E85 or other higher octane fuels? Is it not making more power out of the same amount of air? Or is it just enabling your engine to work the turbo harder without experiencing detonation?

My head is not working too well this afternoon!

My opinion, ethanol makes more power due to the lazy way it burns, right through the piston stroke, which in turn makes more torque. That's why you can pump so much timing in without going backwards or detonating. As the exhaust is cooler and less dense (less carbon?) it actually causes more lag than a petrol tune I have noticed.

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      OK, so regardless of whether you did Step 1 - Spill Step 2 - Trans pan removal Step 3 - TCM removal we are on to the clean and refill. First, have a good look at the oil pan. While you might see dirty oil and some carbony build up (I did), what you don't want to see is any metal particles on the magnets, or sparkles in the oil (thankfully not). Give it all a good clean, particularly the magnets, and put the new gasket on if you have one (or, just cross your fingers)
    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      One other thing to mention from my car before we reassemble and refill. Per that earlier diagram,   There should be 2x B length (40mm) and 6x C length (54mm). So I had incorrectly removed one extra bolt, which I assume was 40mm, but even so I have 4x B and 5x C.  Either, the factory made an assembly error (very unlikely), or someone had been in there before me. I vote for the latter because the TCM part number doesn't match my build date, I suspect the TCM was changed under warranty. This indeed led to much unbolting, rebolting, checking, measuring and swearing under the car.... In the end I left out 1x B bolt and put in a 54mm M6 bolt I already had to make sure it was all correct
    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      A couple of notes about the TCM. Firstly, it is integrated into the valve body. If you need to replace the TCM for any reason you are following the procedure above The seppos say these fail all the time. I haven't seen or heard of one on here or locally, but that doesn't mean it can't happen. Finally, Ecutek are now offering tuning for the 7 speed TCM. It is basically like ECU tuning in that you have to buy a license for the computer, and then known parameters can be reset. This is all very new and at the moment they are focussing on more aggressive gear holding in sports or sports+ mode, 2 gear launches for drag racing etc. It doesn't seem to affect shift speed like you can on some transmissions. Importantly for me, by having controllable shift points you can now raise the shift point as well as the ECU rev limit, together allowing it to rev a little higher when that is useful. In manual mode, my car shifts up automatically regardless of what I do which is good (because I don't have to worry about it) but bad (because I can't choose to rev a little higher when convenient).  TCMs can only be tuned from late 2016 onwards, and mine is apparently not one of those although the car build date was August 2016 (presumably a batch of ADM cars were done together, so this will probably be the situation for most ADM cars). No idea about JDM cars, and I'm looking into importing a later model valve body I can swap in. This is the top of my TCM A couple of numbers but no part number. Amayama can't find my specific car but it does say the following for Asia-RHD (interestingly, all out of stock....): So it looks like programable TCM are probably post September 2018 for "Asia RHD". When I read my part number out from Ecutek it was 31705-75X6D which did not match Amayama for my build date (Aug-2016)
    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      OK, Step 3, if you need to remove the valve body, either to replace it, the TCM, or to do a more complete drain.  First, you need to disconnect the TCM input wires, they are about half way up the transmission on the drivers side. One plug and the wires are out of the way, but there is also a spring clip that stops the socket from sliding back into the transmission. On my car the spring clip was easy to get, but the socket was really stuck in the o-ring of the transmission housing and took some.....persuasion. You can see both the plug to remove (first) and the spring clip (second) in this pic Incidentally, right next to the plug, you can see where the casting has allowance for a dispstick/filler which Nissan decided not to provide. there is a cap held on with a 6mm head bolt that you can remove to overfill it (AMS recommend a 1.5l overfill). Final step before the big mess, remove the speed sensor that is clipped to the valve body at the rear of the box.  Then removal of the Valve Body. For this the USDM Q50 workshop manual has a critical diagram: There are a billion bolts visible. Almost all of them do not need to be removed, just the 14 shown on the diagram. Even so, I both removed one extra, and didn't check which length bolt came from which location (more on that later....). Again it is worth undoing the 4 corners first, but leaving them a couple of turns in to hold the unit up....gravity is not your friend here and trans oil will be going everywhere. Once the corners are loose but still in remove all the other 10 bolts, then hold the valve body up with 1 hand while removing the final 4. Then, everything just comes free easily, or like in my case you start swearing because that plug is stuck in the casing. Done, the valve body and TCM are out
    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      OK, so if you are either going for the bigger fluid change or are changing the valve body which includes the Transmission Control Module (TCM), first you should have both a new gasket 31397-1XJ0A and a torque wrench that can work down to 8Nm (very low, probably a 1/4 drive one). You can probably get by without either, but I really didn't want to pull it all apart together due to a leak. First, you now need that big oil pan. The transmission pan is 450 long x 350 wide, and it will probably leak on all sides, so get ready for a mess. There are 24x 6mm headed bolts holding the pan on. I undid the 2 rear corners, then screwed those bolts back in a couple of turns to let the pan go low at that end, then removed all the middle bolts on each side. Then, undo the front corner bolts slowly while holding the pan up, and 80% of the fluid will head out the rear. From there, remove the remaining bolts and the pan is off. You can see it is still dripping oil absolutely everywhere...it dripped all night.... I got another couple of litres when I removed the pan, and then another few when I removed the valve body - all up another 4l on top of the 3 already dropped in step 1.
×
×
  • Create New...