Jump to content
SAU Community

Recommended Posts

  • Replies 159
  • Created
  • Last Reply

Top Posters In This Topic

some very differnt powers being made with similar turbos. my rb25 with a gt30 .82 and external gate made 420rwhp @ 27psi

ive added a pic of the dyno sheet, the red line is my first engine with aria pistons and higher compression, the blue line is the same head, less compression and wiseco pistons... I had hi flowed injectors, pump, micro tech etc etc...

some of you guys have made good power on such little boost... have any of you gone down the track??

with 300rwhp i ran 13flat @ 114mph

Track I am refering to is Sandown and Phillip Island were i found i had to modify my driving a fair bit so that when i powered out of the corners I could keep the engine in the power curve of the rev range. Sometimes it was a comprimise between using 2nd gear and wheel spinning out of the corner and loosing time or staying in 3rd and having the car bog down for a while till the needle went near 4000rpm.

some very differnt powers being made with similar turbos. my rb25 with a gt30 .82 and external gate made 420rwhp @ 27psi

ive added a pic of the dyno sheet, the red line is my first engine with aria pistons and higher compression, the blue line is the same head, less compression and wiseco pistons...  I had hi flowed injectors, pump, micro tech etc etc...  

some of you guys have made good power on such little boost... have any of you gone down the track??

with 300rwhp i ran 13flat @ 114mph

That is one hell of an interesting dyno graph RNS11Z. It is not often you get the chance to compare the same engine with different compression ratios. Can you notice the 50rwhp less at ~4,600 rpm? Or does it go through the 4,000 rpm to 5,2500 rpm band so fast you don't feel it? I notice that the current set up has ~1.5 psi more boost at 5,150 rpm, is that deliberate? Or did you have to run less boost with the higher compression?

Lots of things to think about on that dyno graph, for a data not like me anyway.:D

I was having problems with the external gate which is why it wouldnt hit target boost straight away on the first engine. When building the 2nd engine we fixed the gate, as you can see it spiked 1-2psi then settled.

The 2nd engine was much more smoother too drive and felt better on the st. The first engine was real snappy.

Peak power on the first engine was 421.??

i think it would be a tad too big, but it all depends on whay you dont mind living with for the extra power. abo bob has got my power graph, when he posts it up for me you guys can have a look how a gt30 with .63 exhaust makes power on an rb25 with stock compression.

wonder how the GT30 with the .63 would go on a rb20 ;) seeing as the rb20 has stuff all puff

i just might have to try it :)

give me about 2 weeks and my rb20 will be in my s14......

its currently got a gt30r with a .63 ar bolted to a hks manifold with the gate set at 14psi/1bar.

i also threw in tomei procams (260/8.8mm lift intake/exhaust) to help it along and some greddy gears.

currently the fuel rail is loaded with some 550's and gonna burn a custom chip to change redline as well as control the larger squirters.

will be using a emanage to tune with a tech edge wideband.......

should go quitenicely......

oh and some one on here said they used a gt30 with a .86 ar on an rb20 and they got 14psi at around 4k.

I wouldnt question the exhaust.

I'd be looking at the ECU/tuner.

One assumes its aftermarket of course... and there is a very big hole in the power band that should not be there at all.

With the smaller housing it should ramp onto boost easiler also. Which i'd put down too the tuneings fault again

That car for the turbo has a smaller powerband than mine with the bigger housing which in thoery should be a bit laggier

Carl... i'll take you for a burn in mine next week if you want and show you how mine goes with a decent tune :)

Hmm, I found a few things that made mine come onto boost alot harder, and hold better to redline - one of them was exhaust being very restrictive. It wasnt a problem until I got the larger turbo on - just choked it as I turned up the boost. Easy way to tell, just drop the exhaust for a quick run around the block :) or on the dyno if your not feeling adventurous.

Second was a flange leak from the manifold to the ext wastegate - only a small one, not audible by ear, needed a stethescope type device - but made a big difference, boost earlier and far more responsive.

Last one was BOV leaking at higher rpm.

Some ideas anyway, hope they help

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



  • Similar Content

  • Latest Posts

    • Ok i will get those 310mm. I found one but on a different site. This is the description on those...is it ok? Technical parameters: - Axle: front. - Disc type: ventilated. - Number of holes: 5. - Disc diameter: 310mm. - Total height with center: 54mm. - Thickness (new/min.): 30/28mm. - Designed for brake calipers manufacturer: Sumitomo.
    • You Gregged a whole racetrack!?
    • Look for broken wire or bad connector at the motor. Might not be it, but is worth starting there, as it is easy.
    • Hi everyone, I’m having an issue with my R32 GT-R. Sometimes, when the car goes over a bump or experiences some vibration, the 4WD warning light comes on the dashboard. When I check the code from the control unit in the trunk, it shows Code 19 – ETS Motor. However, everything seems to be working fine — if I turn off the engine and restart the car, the light goes away and everything functions normally. Has anyone experienced this before? Where should I start troubleshooting this issue? Thanks in advance!
    • I'm back from the dyno - again! I went looking for someone who knew LS's and had a roller dyno, to see how it shaped up compared to everything else and confirm the powerband really is peaking where Mr Mamo says it should. TLDR: The dyno result I got this time definitely had the shape of how it feels on the road and finally 'makes sense'. Also we had a bit more time to play with timing on the dyno, it turns out the common practice in LS is to lower the timing around peak torque and restore it to max after. So given a car was on the dyno and mostly dialled in already, it was time for tweaking. Luis at APS is definitely knowledgable when it came to this and had overlays ready to go and was happy to share. If you map out your cylinder airmass you start seeing graphs that look a LOT like the engine's torque curve. The good thing also is if you map out your timing curve when you're avoiding knock... this curve very much looks like the inverse of the airmass curve. The result? Well it's another 10.7kw/14hp kw from where I drove it in at. Pretty much everywhere, too. As to how much this car actually makes in Hub Dyno numbers, American Dyno numbers, or Mainline dyno numbers, I say I don't know and it's gone up ~25kw since I started tinkering lol. It IS interesting how the shorter ratio gears I have aren't scaled right on this dyno - 6840RPM is 199KMH, not 175KMH. I have also seen other printouts here with cars with less mods at much higher "kmh" for their RPM due Commodores having 3.45's or longer (!) rear diff ratios maxing out 4th gear which is the 1:1 gear on the T56. Does this matter? No, not really. The real answer is go to the strip and see what it traps, but: I guess I should have gone last Sunday...
×
×
  • Create New...