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100 Ron And Cam Sprocket Re-tune

OZ GTR35

By OZ GTR35,
in New South Wales

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OZ GTR35 Veteran

OZ GTR35

Posted
Posted

All,

I had my GTR re-tuned with 100 ron fuel and cam sprockets today. The results are not mind blowing but as you would expect I did get an increase in Power. Basically I recieved a 10-25 Kw increase across the board, with a little less boost and a little more fuel. The car does feel stonger and boosts up quicker, If you look into my original go-Fast central post you will see the mods. http://www.skylinesaustralia.com/forums/in...go+fast+central

My old figures were

225KW @11PSI

245KW @13PSI

265KW @17PSI

283KW @19PSI 6800N

My new numbers are

235KW @11PSI

255KW @13PSI

275KW @17PSI

293KW @19PSI 7200N

The first pic is pre and post tune at 11PSI. the mid range has in some places increased by 20KW which is nice, at 80Km old power was 63kw, now 85kw, which makes the car feel a lot quicker at low RPM's

Then next 3 pics are the overlay of my 4 hot runs back to back at 4 different boost settings.

The car was not strapped down either.

post-42-1149916860.jpg

post-42-1149916889.jpg

post-42-1149916923.jpg

post-42-1149916953.jpg

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https://www.sau.com.au/forums/topic/121706-100-ron-and-cam-sprocket-re-tune/
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dori34 Grand Master

dori34

Posted
Posted
Hrmm I sorta woulda expected those kw increases just by filling up with 100ron over 98ron let alone camgear adjustments and a retune....

a retune of the cam sprockets and the computer was a wise thing to do.

if you just put in 100RON it wouldnt be able to run at its best OR it could've ran like shithouse.

you gotta change the tuning of the ecu and the cam sprockets to adapt to the new fuel so it can perform at its best.

OZ GTR35 Veteran

OZ GTR35

Posted
  • Author
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Nice result.

Is that where the car is gona stay or are there future plans?

No thats enough, after driving the car yesterday, I dont know where I could use any additional power except on the track. I need to keep my car running, its a work car and I do about 30-40k Km per year and about 10+ track days a year. If i want to keep the car reliable and I want more out of it I will have to spend heaps of money.

OZ GTR35 Veteran

OZ GTR35

Posted
  • Author
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Hrmm I sorta woulda expected those kw increases just by filling up with 100ron over 98ron let alone camgear adjustments and a retune....

?

Benm, the first dyno shows exactly that, a 98 ron tune with 100 ron fuel, and the increase is the re-tune with no change in fuel. I was expecting a 20Kw increase was at the top end, but only got 10kw where everyone looks, the final top line figure. But the car did get 20kw's+ in some places, mainly in the street and track areas, as Im very rarely at 7800rpm at the track. Another point is the tune is safer then before, more fuel, less boost, less knock and more KW's, the perfect outcome.

I guess the difference was, I did not walk in and ask for as many KW's as possible, I asked for a supper safe track tune that will do 40,000km a year as well as a dozen track days per year, and I need the car to last another 2 years! I would suggest this is not a normal request for a GTR tune, hence why I did not end up with huge numbers.

I guess at the end of the day Im happy with the car and power figures, and as long as Im happy its all good!

OZ GTR35 Veteran

OZ GTR35

Posted
  • Author
Posted
a retune of the cam sprockets and the computer was a wise thing to do.

if you just put in 100RON it wouldnt be able to run at its best OR it could've ran like shithouse.

you gotta change the tuning of the ecu and the cam sprockets to adapt to the new fuel so it can perform at its best.

My car ran really well on just the 100 ron, as the fist dyno shows, I did a couple of track days on the 100 ron the knock was lower then normal, but I did not feel any real changes in peformance. I did get an additonal 80km out of the car on long trips which was nice. 590km out of 1 tank earlier this year up the kempsy.

OZ GTR35 Veteran

OZ GTR35

Posted
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Too bad i didn't get there earlier to have a chat today Paul, cars going well though I see. Have to catch up soon ey.

Sorry mate, just missed you, I thinking of having a Friday arvo at my house in a few weeks the Boss will be in Melb with the kid, I will send you a PM.

shonen Grand Master

shonen

Posted
Posted
No thats enough, after driving the car yesterday, I dont know where I could use any additional power except on the track. I need to keep my car running, its a work car and I do about 30-40k Km per year and about 10+ track days a year. If i want to keep the car reliable and I want more out of it I will have to spend heaps of money.

Finally somone that can answer a question ive been wanting to ask for a while...

How is the GTR as a daily driver doing that many Ks ?

I do the same amount of KMs per year.....and thats in GTT, is the GTR too hardcore for daily driving doing that many Ks ?

Cause even now I sometimes wish I had a second more "comfy" car for daily driving.....

Beer Baron Grand Master

Beer Baron

Posted
Posted

nice work paul. my only question is which 100ron fuel? was it optimax extreme? I am getting curious about using it in my car. we just switched from avgas to extreme for the race car and didnt really notice any drop in performance, and the extreme is easier to get, and cheaper (not by much though). in fact we were testing it for the first time the other day at Aarons day. and used it again this weeked with no problems.

Tommyk Veteran

Tommyk

Posted
Posted

Shonen, I think I covered 25k daily driving when I had my gtr. While its not a pain in the butt driving it on a daily basis, some roads are pretty unbearable. I blame the reasonably stiff factory vspec suspension. Other than the stiff ride, Ive had no gripes driving my gtr daily.

The only thing I can say, is that once I had it modified (larger than stock turbos), I lost a fair bit of mid range power, which made it less practical for driving at normal city speeds. For a street car, I think both Nick, Paul, Kris and Jerry have done well in their turbo choice :wave:

Oh and in relation to the topic, I had my car tuned for 100 RON fuel. I took it out to oran park and while I had extreme in the car, my knock levels did not exceed 30. The car had great power and smooth response. I then tanked up on optimax, and noticed an increase in knock spikes, up to around 40-45. Id suggest using extreme to be definitely worthwhile. The car should run smoother and knock should be reduced. You can always have a play around with timing on the pfc :dry:

Tommyk Veteran

Tommyk

Posted
Posted

Nah Jerry not yet. Buyer backed out.

I suppose the reason why knock was lower, is that the car was tuned for 100 ron. I used shell extreme (i know of no other 100ron fuel?). I found that running the extreme, I could play with the timing a fair bit more before I started to hit near 30 knock for daily driving stuff. It was VERY noticeable on the track, however, in that knock levels did not rise above 30, wheras straight after on the same day with the same temperature, and boost levels, a full tank of optimax saw me hit 45 on the pfc hand controller. Coincidence? Maybe? Bad batch of fuel? Maybe?

Try it out. 5% ethanol isnt going to kill your fuel lines. At least not in the short term :)

Beer Baron Grand Master

Beer Baron

Posted
Posted

ahh thanks. there are other 100ron fuels. i believe united make one, avgas is also 100ron and elf make a 100ron too. i'm sure there is even more than that around though.

jerry yes i'm still a sceptic on it too. let me put it this way, i wont use it in the GTR just yet, and if i did i would go to the dyno, and fill it up there from drums. But like i said we did switch around a bit in the white race car from elf LMS to avgas, to pump fuel (optimax), then back to avgas, then to opti extreme. and not much difference bettween them, though it did seem a little crisper on the elf lms but it's $6 per litre... having said all that this is a 2 litre carby fed car, not turbo'd but it is high compression and highly tuned, and gets absolutely pounded.

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