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My money is on gtsboy

This. I half wanted to weigh in here too, but I'm sticking to my "Try not to care too much about forum conversations" pledge and he has a habit of saying things I am thinking anyway so I get the enjoyment of it without the frustration of writing lots of stuff and finding a lot of it falls on deaf ears, or gets recycled and then regurgitated back to you as though you are being taught something so this works much better for me :)

The whole way this started was comparing like setups anyway, its going kind of off topic anyway - we end up down a path of levels of extrapolation in the comparison getting bigger and bigger and it reaches a point where we may as well say "BLARH my Dad is bigger than yours". If no one else does I'll try and collect some useful data on the SS2 when I get into tuning it.... I kind of wish I still had GT3076R log data on hand, but either way its clear than the boost threshold difference is probably trivial which makes the SS2 a good thing, again because of how convenient it is price and bolt-on wise.

  • Like 1

Yo Lithium, logs attached!

Looks like I get:

1.1bar at ~3600rpm

1.5bar at ~4300rpm

However like I said earlier, my gain is set pretty low

Also here's a virtual dyno print out, not sure how accurate this is either lol

post-22311-0-20871300-1411045124_thumb.png

9-18-2014_2011.xlsx

  • Like 1

Awesome, good data sir! Will check out the xlsx when I get to a computer but that gives a good idea. Very very similar to a GT3076R, solid looking power too :) I know VD had issues with MAP in he past, I assume it still does but still... seeing 3.6 bar on the pressure plot for a stock 25 makes my eyes water haha.

Just confirming, is externally gated?

Cheers for sharing :)

Of course you can!

Just download it, choose the right car/tyre settings and upload your logs.

You'll need to trim the logs though so it's only one WOT run in 3rd or 4th. I tried to upload an entire log and it turned out like a mess lol

I think the 2 conflicting examples of spool of E85 vs petrol goes to the heart of the matter. I am no expert but I thought I'd put my musing in here.

I'm assuming it does indeed come down to heat in the exhaust flow which comes down to comparative AFR during spooling. If tune E85 and petrol to the same lambda during spool then the extra E85 mass at a given lambda will reduce heat in the exhaust compared to the petrol tune and reduce spool. If you tune E85 to a bit leaner during spool then this effect will be minimised and perhaps even allow E85 to bring on boost sooner due to the greater power & heat generated. Since E85 gives a wide sweetspot for MBT then it does allow it to be a bit leaner during ramping up without affecting timing.

^^ This is probably very true.

If you take the freedoms given to you by E85 and run with them, you will almost certainly be able to overcome the cooler exhaust effect.

The reason I said I wasn't going to do the math is that I was sitting in San Fransisco Airport United Lounge between a 6 hour trans con flight and a 15 hour trans Pacific flight. Simply wasn't interested in anything that even seemed remotely like the work I had been doing for the previous 3 weeks. Now that I'm home, and not going to the office this weekend or Monday, I'm still not interested.

Maybe later.

I'm thinking better torque timing in the spool phase but injector performance would play a part here . A big old world injector won't react or probably atomize as well as a modern one so being rich here is probably safer overall .

Ill tell you this

My tune with the ss2

98 = ~355whp @ ~18-22 psi

85 = ~345whp @ 16 psi

The 85 tune has alot more midrange, comes on power alot harder.

Its also faster...proven at racewars.

Ill tell you this

My tune with the ss2

98 = ~355whp @ ~18-22 psi

85 = ~345whp @ 16 psi

The 85 tune has alot more midrange, comes on power alot harder.

Its also faster...proven at racewars.

Do you have the torque graphs? I would be interested to see your torque gains running similar power output, on the same turbo.

Updates on the GTR. 130KMs drive to see Brandon at Brae fabrications. It is now now high mount installed, running one of our 50mm external gate.

car.JPG

enginebaystock.JPG

manifold1.JPG

manifold3.JPG

manifoldback.JPG

Don't know if this is a N1 GTR. Factory turbochargers removed are busing bearing N1s with steel turbine wheels. That explained all the extra power.

stockturbo.JPG

Turbocharger used for this evaluation is our latest billet SL20.5

front.jpg

turboinstalled.JPG

I've heard few people mentioning that the Rb26dett engines are laggier at spooling up the same turbocharger as if it is installed on a Rb25det due to the lack of VCT unit. It didn't feels like the case. Be interested to see what the dyno says and comparison against standard Rb25dets using the same turbocharger on similar setups.

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