Jump to content
SAU Community

Recommended Posts

All good man just having a friendly dig.. :thumbsup: Back on topic...

Fair enough... was a bit cheeky though! ;) I am a bit of a nerd especially when I don't know something, come hell or high water I want to know exactly what and how happens.

To rob82 my comments were more to suggest that an internal wastegate creates more back pressure on the exhaust side. I also think you answered your own question as well... why would you have a large frame single turbo on a small capacity engine with small cams? Engine would choke before the turbocharger even came into its own.

  • Replies 81
  • Created
  • Last Reply

Top Posters In This Topic

Fair enough... was a bit cheeky though! ;) I am a bit of a nerd especially when I don't know something, come hell or high water I want to know exactly what and how happens.

To rob82 my comments were more to suggest that an internal wastegate creates more back pressure on the exhaust side. I also think you answered your own question as well... why would you have a large frame single turbo on a small capacity engine with small cams? Engine would choke before the turbocharger even came into its own.

I honestly think that most internal wastegated turbo would cause less flow disruption/diversion at the point of gating than most externally gated setups. Hence the exhuast backpressure would be less for the same size turbo with an internal gate vs external gate.

Also I was just trying to point out before that if response is the goal massive cams are not the go.

No better example of this than ole mate Marko really.

About time you did, everyone will benefit.

I mean you supposedly asked for a tune without a midrange...

And are firmly on the big cam bandwagon this month:

Yet only 2 months ago you come out with this?

Says it all really. :rolleyes:

i am not prepared to go into detail of my old engine setup as it is not my business to share this intell, however, i will tell you that the engine is running 100kw less - case closed.

my cam choice has ALWAYS been chosen by my tuner - not what i read on the internet from a computer warrior. for example, would someone who has built many rb's (i.e. CRD, RIPS, Red R Racing, Hi Octane) carry more weight than a someone like yourself or me for that matter? stop kidding yourself...how many engines have you built ash & how many combinations have u personally tried?

i have had this thread reviewed (not disclosing name) i am sure you will keep following me around as its blatantly obvious, please stop trolling and posting off topic as this is not the 1st time.

thank you & sorry guys

I honestly think that most internal wastegated turbo would cause less flow disruption/diversion at the point of gating than most externally gated setups. Hence the exhuast backpressure would be less for the same size turbo with an internal gate vs external gate.

Also I was just trying to point out before that if response is the goal massive cams are not the go.

Sorry mate you are wrong there on your first paragraph.

Yes, you want response choose small turbos like HKS GT-SS or N1 upgrade (which means high exhaust manifold back pressure) and chosing short duration camshafts with little or no overlap.

Sorry mate you are wrong there on your first paragraph.

Yes, you want response choose small turbos like HKS GT-SS or N1 upgrade (which means high exhaust manifold back pressure) and chosing short duration camshafts with little or no overlap.

Can you explain why I am wrong.

I dont think you understand what I am saying - try reading my post again.

Under the assumption that the external wastegate is vented to atmosphere your theory is incorrect.

Arguing with you is like masturbating with a cheese grater - slighty amusing but mostly painful!

WTF are you talking about.

  • 2 weeks later...

Real world data. Rb26 at 86.5 bore, stock stroke, all steel internals (endurance spec build, probably overkill, but I hate failures), Tomei 280 degree 10.8 mm lift cams, Tomei cooling channel pistons at stock CR, Motec M800 ecu, stock TB's, stock CR, mildly ported head, all manifolds port aligned, stock ported cast manifolds, NO AFM's, MAP / Throttle based but with 4D mapping, stock elbows, -10 turbos, 3 inch ultra quiet exhaust (98Db at 2/3 max rpm static), 850 CC injectors off single 044 pump, in a GTS-T RWD shell. 1.2 bar boot. Motec shows absolute, not gauge pressure. mikey whatsisname speaks a lot of sense, IMHO.

http://www.gatesgarth.com/datalog.png

In car with basic data overlay from same track day:

Manually synched to video, so a tad out, sorry.

I want to try the bigger -10 turbine housings. Car is a pussy cat on the road, no shuffle at all, totally pleasant off boost and at cruise. Would benefit from a less restrictive exhaust system, exhaust manifold pressure V boost pressure ratio is not brilliant, but here in the UK noise is a major issue. Car runs from the roadside pump Shell V power, no det, no issues.

Edited by Chris Wilson

I think your throttle % mapping is a bit out, highest it gets too is 65% or so whilst the 'bar' is maxed?

5500rpm in second @ full noise before 1.2bar. Maybe you need 290 cams as well to bring them on @ 4500rpm like some around here have claimed :rolleyes:

Pity the data cuts out half way through the video man, it was just looking to get interesting :(

Yes, I am just trying this manual data overlay app (Race Render, it's me, not the app as such, it's trickier than I imagined...), I am beginning to wonder just how far from synched this is, take it with a pinch of salt, but you get the basic idea. Just shut one eye ;) Automagical synching is available from Motec, but the bank manager is dubious about its merits this month ;)

I am in the UK, but try and keep an eye on all the Skyline sites. Cheers. I may have another go at doing a better synch. I have sold my Go Pro Hero camera and for next season will either get the Motec stuff if they come good on their intent to offer a higher resolution camera setup, or buy a camera that time stamps the video. The GPS data channels have a GPS time function, so tying up the two should be far easier then. Cheers.

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

    • I know why it happened and I’m embarrassed to say but I was testing the polarity of one of the led bulb to see which side was positive with a 12v battery and that’s when it decided to fry hoping I didn’t damage anything else
    • I came here to note that is a zener diode too base on the info there. Based on that, I'd also be suspicious that replacing it, and it's likely to do the same. A lot of use cases will see it used as either voltage protection, or to create a cheap but relatively stable fixed voltage supply. That would mean it has seen more voltage than it should, and has gone into voltage melt down. If there is something else in the circuit dumping out higher than it should voltages, that needs to be found too. It's quite likely they're trying to use the Zener to limit the voltage that is hitting through to the transistor beside it, so what ever goes to the zener is likely a signal, and they're using the transistor in that circuit to amplify it. Especially as it seems they've also got a capacitor across the zener. Looks like there is meant to be something "noisy" to that zener, and what ever it was, had a melt down. Looking at that picture, it also looks like there's some solder joints that really need redoing, and it might be worth having the whole board properly inspected.  Unfortunately, without being able to stick a multimeter on it, and start tracing it all out, I'm pretty much at a loss now to help. I don't even believe I have a climate control board from an R33 around here to pull apart and see if any of the circuit appears similar to give some ideas.
    • Nah - but you won't find anything on dismantling the seats in any such thing anyway.
    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
×
×
  • Create New...