My 300rwkw Adventures

[bhappy]

That must have been the happiest dyno in the world.

There is no f**king way in the world that a GT3071 would make 280rwkw on a S15 at 15psi.

Mine is making 300rwkw on 18psi, and the turbo is much larger. (bigger compressor and turbine, etc)

Looking at the flow maps will prove this....

Well 280rwkw was made on Croyden Racing Developments Dyno Dynamics Dyno in shootout mode on 98 Octane BP. I think its probably one of the most accurate dyno's in the country. Andrew aka Dumhed, the guy who smashed all the skylines at the most recent Skyline Australia NSW track day down at wakefield was there and witnessed it. Jim the head tuner at CRD tuned it. Obviously you can't read those maps very well since Im making a genuine 280rwkw.

Regards,

Albert

[The Mafia]

ok, so how do you know its genuine? How do you even know its the most accurate dyno in the country?

I bet if I dropped my car on there it would probably get 340rwkw or something......

I can read maps, and I can certainly tell you that what you are claiming is BS. I had to use water methanol injection on a much bigger turbo to make 300rwkw. If I took the WMI away, I'd drop to 270rwkw - 280rwkw. What you are telling me is that your "280rwkw" on your smaller turbo on LOWER boost is going to make the same amout of power, than a bigger engine, with a turbo that has a bigger turbine, compressor, and bigger trims?

I'm still going to say that that dyno readout you have is crap. There is NO WAY a smaller turbo, running less boost is going to out perform a bigger turbo of the exact same type, running more boost. Why would garrett bother selling the bigger one then? Plus it's physically impossible.

Read the maps, I can guarantee that dyno reading is way too happy. Either that or come to the mainline here, and you'll get a real reading. I was told my car on a Dyno Dynamics would read 20-30rwkw higher. But I don't care, I use the dyno as a tool, measure my afr's, and not lose my license. My termial speed is what I have been looking at.

Whats your terminal speed down the quarter mile? Thats the only way you can accurately predict what you are claiming.

Edited August 18, 2007 by The Mafia

[Dale FZ1]

Regardless I still believe the 71mm comp wheel is only good for a little over 250rwkw (depending on the dyno) 76mm good for a little over 300rwkw and the 82mm (60mm turbine) good for the same as the 76 on pump but good for a little over mid 300's on good fuel. GT35r good for 400rwkw.

I tend to agree with your views here. Sure, the turbine efficiency is a major moderator of overall performance, but the compressor MUST be able to efficiently supply the mass-flow in the first instance. That drop in efficiency and rapid rise in shaft speed for the 71mm GT35 comp family tells against it if someone was shooting for 300rwkW. It could get somewhere near the 275 mark but no more on a R33 Skyline. Other cars with lighter drivelines and lower power losses, who knows?

not sure if it helps the discussion but with changing my chinese stainless low mount to a highmount Extreme turbo manifold, running a proper merge colector, i not only picked up around 20 kws at the wheels, but i also noticed a lack of knock compared to the previous manifold.

this is running a GT3582R-IW with a .82 rear.

no boost creep or drop to complain about.

I think this helps heaps. Good info.

Makes me wonder how this setup would perform with a manual box.

A 3071r is easily capable of 300rwkw. I have one on a s15 sr20det stock bottom end and at 15.5psi its making 280rwkw on CRD's dyno. Just ask jim if you don't believe me, he tuned the car =)

Standard bottom end, but what about top end work? Go right to the start of this thread and you'll see Mafia is running an internally STANDARD engine.

An SR20 can liven right up, but cams are the key to making it work. Conventional stuff, same as the RB series. Still, I suspect the reading might be slightly "happy" given your boost and engine capacity. Good work and the information is good but not quite on-thread. See above comments about different powertrain efficiencies and compressor mass-flow abilities.

[bhappy]

ok, so how do you know its genuine? How do you even know its the most accurate dyno in the country?

I bet if I dropped my car on there it would probably get 340rwkw or something......

I can read maps, and I can certainly tell you that what you are claiming is BS. I had to use water methanol injection on a much bigger turbo to make 300rwkw. If I took the WMI away, I'd drop to 270rwkw - 280rwkw. What you are telling me is that your "280rwkw" on your smaller turbo on LOWER boost is going to make the same amout of power, than a bigger engine, with a turbo that has a bigger turbine, compressor, and bigger trims?

I'm still going to say that that dyno readout you have is crap. There is NO WAY a smaller turbo, running less boost is going to out perform a bigger turbo of the exact same type, running more boost. Why would garrett bother selling the bigger one then? Plus it's physically impossible.

Read the maps, I can guarantee that dyno reading is way too happy. Either that or come to the mainline here, and you'll get a real reading. I was told my car on a Dyno Dynamics would read 20-30rwkw higher. But I don't care, I use the dyno as a tool, measure my afr's, and not lose my license. My termial speed is what I have been looking at.

Whats your terminal speed down the quarter mile? Thats the only way you can accurately predict what you are claiming.

I know its genuine because I have the dyno chart from the dyno readings which was witnessed by Jim the head tuner at CRD and andrew aka dumhed, and the other people that were there. Jim is one the most reputable tuners in Australia and knows how to precisely calibrate and maintain his dyno. Also I never claimed it was the 'most' accurate dyno in the country. I said 'I think its probably one of the most accurate dyno's in the country' Nice to see that you can read what I write as well as you can read maps. I think you should do some research into CRD before you start saying that the readout from their dyno is crap.

There are plenty of ways that a smaller turbo, running less boost is going to out perform a bigger turbo of the exact same type, running more boost. Ie. Quality of tune, Higher fuel Octane, different engine components, etc.

So if you were told 'my car on a Dyno Dynamics would read 20-30rwkw higher.' Why did you state in ya first post that 'Oh, and apparently the Dynodynamics dyno's in mackay here (there are 2) are reading 10rwkw - 20rwkw MORE than this dyno.'? Did you get some new information from somewhere?

Also Id like to find out how you can guarantee that my dyno reading is way too happy? I haven't bothered to take my car down the quarter mile as yet, as I m not really all that interested in quarter mile times.

Regards,

Albert

Edited August 18, 2007 by bhappy

[Cubes]

Dale,

I believe before the high stall Dangerman4 made up around 317rwkw with a little less boost and on std cams?

The high stall sucked a bit of the power 'reading' out of it.

-------

bhappy,

As you may know boost is a restriction to airflow.

I'm guessing you have had some serious top end work and the larger .8 turbine housing to make those numbers on such a boost level.

Just because its making 280rwkw on 15.5psi it doesn't mean that there's anything left in it. Boost is a restriction to airflow.

'Generally' speaking a bolt on type setup (std motor) the figures I have quoted are pretty spot on. Going by the dyno I run on.

I'd be curious to check out the dyno sheet..

Assuming it was done in shoot out mode?

Do consider different shoot out modes read slightly different power levels. Throw a car on in shoot6 and get x reading; change the shootout to shoot8f and watch it pick up 20-30rwkw. Then there's how hard the car is strapped down and another variable which is easily fiddled with the placement of the IAT sensor.

Hang the IAT sensor on the wall; its the only way for a 'genuine' reading. Why inflate a reading due to a poor inlet setup when with the bonnet shut and on the road its going to be sucking hot air and not able to 'magically' make more power because of it.

[bhappy]

To Cubes

My car has had some top end work as you can probably tell but nothing too serious. Only HKS Step 1 Cams and Tomei Rocker Arm Stoppers. My exhaust housing is the 0.63 exhaust housing. Also my dyno was done in shootout mode, shoot6.

Regards,

Albert

[wolverine]

i reckon 280rwkw with cams/mild headwork etc is accurate/possible/likely at CRD but i also agree with cubes that 15.5psi might possibly be wringing its neck.

Edited August 18, 2007 by wolverine

[Cubes]

To Albert,

Post the dyno sheet; yes spamming the thread a little but if you make claims u do have to back them up.

Either way I did say a little over 250rwkw on the dyno I run on (and assumed as it is a skylines forum) with the rb and its driveline (the 25t box does soak a little more up than the rb20t box for example).

[bhappy]

To Cubes

Here's the dyno, Jim said it was making the power easily, without having to push it. We left it at 15.5psi because its only a stock bottom end and its better to stay on the safe side when ya haven't budgeted for a tomei crate engine any time soon Full boost is made at approx 4200rpm. Rear tyres were 255/40/18, Diff ratio is stock, 3.692. 5th gear is 1:1 ratio in s15.

Regards,

Albert

Edited August 18, 2007 by bhappy

[Busky2k]

Alberts dyno is pretty spot on IMO, I pull 252rwkw on Unigroup (reads almost identical to CRD's dyno) and his car kills mine on a roll on.

Btw I don't think the 56T 71mm is too small. It pushes 48lb/min which is 480 crank hp on the old money. It definitely can flow some air.

[Adriano]

Congrats albert, thats a good result from the mods, however it isnt run in shoot 6F(it really should be Shoot 4F), so there is a difference in the ramp rate and the power reading, an NA mx5 that i tuned showed over 15rwkw between shoot4 and shoot 4F, and that only made 135rwkw

[Lithium]

ARGH what is it with people here and complete intolerance to dyno's which read higher than your notoriously low reading dynos? If it reads higher than yours, it isn't WRONG - same if it reads lower. Its just DIFFERENT.

Look around the world, making >400whp on pump gas has been done only plenty of DSMs and SR20s around the world. People have made in the region of 500whp with GT3076Rs, and GT3582Rs are often considered as near 600whp capable. We all know you shouldn't expect that on a Dyno Dynamics - the reason for this isn't that they are happy dynos or that yours are sad, its just that they are different. If you need a right or wrong, then majority rules would say that the Dyno Dynamics ones are the ones which are wrong because to some degree it appears that results on the net from Dynapack and Dynojet out number DD.

Its just a tuning tool.

Edited August 18, 2007 by Lithium

[The Mafia]

ok, looking at the extra mods, I'd guess that was a little more believeable.

I've still think that the shootout mode you are using, if I used it on that dyno I'd blow right over 300rwkw.

Where is your torque graph?

[Cubes]

Well I didn't realize the little SR20 was such a capable performer. Ignorance is bliss.

A little searching it appears the sr20's do usually see 280rwkwish but with stage 2 (260in 270exh) cams and the 3071 hanging off the side. 280rwkw on 15.9psi or what ever it is looks like with stage 1 cams & stock bottom end looks like good strong power.

The SR20 essentially is 4cyl RB30 when you consider bore, stroke & valve size etc; would be interesting to see how the rb30det would perform with such cams and the 3076. As it is the rb25 head from factory runs quite small cams compared to the stock sr20 head so no doubt some big power gains are lurking if we were to run some decent cams.

Sky30's rb30det is a good example; gt35r .82 17psi (@3400rpm) 380rwkwish with reasonable cams and plenum/exhaust manifold compared to his old setup 312rwkw (18-19psi gt35r .82) with std plenum, smaller cams, std exhaust manifold.

Given the 460hp rating of the GT3071r minus the skylines usual 70rwkw drivetrain loss thats ~275rwkw.

The Gt3076 @ 525hp; thats around ~320rwkw.

So pretty much on the money from what I've seen over the years.

[discopotato03]

I start too many fires don't I

There are a few different versions of the "GT3071R" and they don't all use the same turbine . The good one is basically the real GT3076R but with a GT35 71mm compressor and a 0.50 A/R T04E compressor housing . The real GT3076R has the GT37 76mm compressor and a 0.60 A/R T04E compressor housing .

From the maps of the as delivered GT3071R (real one) the compressor maxes out at 50 lbs corrected flow on one of my maps . This is in the T04E comp cover at ~ 3.2 pressure ratio or 2.2 Bar positive . At 2.2 PR/1.2 PR positive/20.5 lbs boost it shows around 46-7 lbs of air . The fluid dynamics people say that 1 lb of air can be used to make 11 Hp so thats how many work out the power potential of a turbo - but only from an air point of view . Don't forget the exhaust side .

Real world the main differences between these (3076R/3071R) is that the larger compressor wants to pump more air for a given shaft speed than the smaller one . It also takes more turbine energy to drive than the smaller one so all else being equal it will bit a bit more lazy getting up to speed . Look at it like more gas (air) has more mass and in turn needs more shaft power to turn the compressor .

If you read my past rantings you'll remember I said the GT3071R is a good combination but it's fickle with the choise of turbine housing A/R . This is because it needs a lot of compressor revs to deliver high airflow rates and reasonably high pressure ratios (boost pressure) to get there . To get good high end performance these turbos NEED a free flowing turbine housing section and low turbine inlet pressure (exhaust manifold pressure) . If you go the traditional route with a single scroll turbine housing its going to have to be a large one otherwise the turbine inlet pressure gets unacceptably high and this chokes the engine/turbo to the point where power hits the wall even if you can supress detonation . Judgement call , response vs top end .

The reason Twin Scroll followers can get good power from these turbos is because they throw off most of the need some mid range response so can't get away with the large A/R single scroll turbine housing scenerio . With a propper Twin scroll housing you can have a largish A/R , pressure pulses timed to strike the turbine blades without having to fight their way through the artificially high pressure created by other cylinders .

Anyway long story short you can have the turbos turbine reasonably large in relation to the compressor and not suffer the turbine lag penalty . Garrett have been building Diesel turbos like this for ages and most of them use TS turbine housings . They have things like GT3571's with the Diesel spec GT35 HP (high Pressure Ratio) turbine and the GT35 71.1mm compressor . They also have a GT3576/R with the GT35 HP turbine and the GT37 76.2mm compressor . Then you get into GT3776 and GT3782 (GT37 turbine is 72.5mm) with the GT37 76.2mm or GT40 82mm compressors like GT3076R and 3582R's use .

The bottom line is if you want big engine torque from a smaller engine with about the best NA like characteristics possible then TS is the way to do it . Other than that put an LS1 in it .

Cheers .

[Dale FZ1]

Looks like something that belongs in that Split Pulse Turbochargers thread. I've no probs with the technical aspects, just the expense of the extras (namely a properly setup manifold + external gate) to make it work.

Cost:benefit analysis still has this particular style of bolt-on upgrade particularly effective. There are other variations like Dangeman4 has with his GT3582, and the 7 bladed GT30 but the concept and expense are much the same. Bolt-on, no internal parts or porting; just some careful tuning with the advantages of WI.

A 3071 like Albert's, or a split pulse could hit close to the 300rwkW that Mafia did, but on an RB25 you've just spent a lot more money to make it happen. I'm still waiting patiently for Full Race Geoff to complete those back to back tests. Still we're only getting an idea of who won the dyno race, which isn't the most important thing as Lithium pointed out.

Results on the road or track, and impact on the bank balance are what I'd focus on.

[discopotato03]

Well if you put either (3071R or 3076R) on an RB25DET with one of the larger A/R turbine housings you can make the power easily enough , but the low to mid range torque will suffer because the gas speed through the turbine nozzle wont be very high at lite loads .

Dale you can't have it both ways with the conventional system . You either have the response from a smaller exhaust housing or the high flowing low pressure advantages of a large housing .

I really can see why Nissan used the parallel twins on RB26's and this is another option if the cost of TS manifolds/ext gates/TS turbine housings is beyond reach . Neither system is cheap but the same basic advantages can be had either way .

Real performance is rarely cheap , cheers A .

[skylinecouple]

I`m with you Dale.Price is just as important if not more than a handfull of kws.So would Disco agree if you have a smaller compressor like the 3071 with an .84 or .82 turbine there should be no exhaust restriction and the added benifit of fast spool up or certainly slightly better than a 3076 with a .63 turbine housing.What would be interesting is a 3076 with .82 housing and compare spool up.Also, does the 3071 come with an anti surge compressor inlet?

[Dale FZ1]

Dale you can't have it both ways with the conventional system . You either have the response from a smaller exhaust housing or the high flowing low pressure advantages of a large housing .

Real performance is rarely cheap , cheers A .

I agree. The point all through this thread has been that compromise is part of the equation. Technical solutions cost real money, and the smart punter has to know where/when to accept compromise. Know if they'd rather have a couple of G left untouched, or know whether having that potential for a slightly fatter curve is going to make a REAL difference to them.

Again, the dyno sheets only show full load behaviour and don't say much about transient response. We've said it earlier on this thread and others about the value of "feel" ie what happens with 1/4, 1/2 and 3/4 throttle, and driveability. It may be that by the time someone fits up a turbo (any of those discussed) with 500 crank hp potential, cams the engine (if desired/needed), plays with porting etc that they've got a far more lightswitch style delivery than expected. Again, that's part of the compromise that goes with their target while running a smallish capacity RB25.

So for me, there are many facets to the whole deal.

cheers

[discopotato03]

Yes compromise is the point to be sure . I don't look at the RB25 as being so much small though a little short on torque low down in the rev range when it comes to shifting a 1380 odd Kg R33 Skyline . Its more the power delivery characteristics that I would like to change . The thing you are going to find is that no matter which way you attack this problem its going to cost some reasonably serious money . If you put more cubic inches under it then thats a valid way to pull up the bottom end torque but is a fair bit of work and money . If you pull the head off it and do the ports/exhaust valves/cams also time and money . If you replace the exhaust manifold turbo and wastegate thats not cheap either .

Its this wanting it on the cheap thats going to compromise the result . The major obstacles are the state of tune of the standard engine and what it takes to alter its characteristics .

Now everyones budget is their own issue and the honest truth is that if they want serious grunt its available but in budget form not as nice as it could be . If you have to drive the thing every day and the dollars are short then I think the practical plan is to aim a little lower and give up the bit up high for a more even result everywhere else .

Cheers A .