Hypergear Turbochargers and High flow Services Development thread

[RandomHero83]

Silly move. I done my 100k service 10kkm before it. Pay for tune, major service, then pay for tune again...

Didn't have the spare cash laying about to do the service early, Opting to enjoy it as it is now and when i feel the need for more power then up it again, will cost me bugger all on the retune so that's not a biggie.

[Rolls]

Silly move. I done my 100k service 10kkm before it. Pay for tune, major service, then pay for tune again...

It will just be a touch up tune, not like he will have to do it from scratch, no biggie imo.

hopefully it will be totally different weather as well, might give him the opportunity to perfect it slightly.

Edited January 15, 2012 by Rolls

[jet_r31]

By all means compression test the engine before modifying any car.

I am curious what difference you think running 18psi vs 21psi will make. If the car is kept away from det how is the ringland going to fail?

12psi with det will fubar it as easily as 18psi.

I am not talking about all turbos just these ones ( and a lot of others in the 50lb to 60LB flow range) . and 98 octane. At 18psi they are loafing along at, probally would be hard to get the bigger ones hot at all.

at 22psi however they are generally out of compressor flow on 98 octane which means

intake temps are higher, EGT's would be higher and i bet combustion pressures are a lot higher, not to mention that on 98 octane theres a fair bit of tuning balancing work at that level

I suspect that the chances of blowing a motor ramp up over 20psi. Woudn't hurt a freshy, but face it, theres plenty of uncared high km Rb25s out there

It the exact same thing in the Rb30 sohc world aswell with the same size of turbos.

Pretty sure STATUS even said he won't tune a Rb25 over 18psi without knowing its condition and health.

But yeh thats just my opinion, everyones got one, its the internet...lol

cheers

darren

Edited January 15, 2012 by jet_r31

[Rolls]

The chance of detonation does go up exponentially with more boost, but I am of the opinion if you tune badly enough to blow it up at 22psi, then the motor has no chance at 18psi. The same level of care is required in both situations, the same safety margins are required.

What is the biggest factor for detonation at these sort of power levels, is it combustion pressure? Or is it intake temperature, I know both are major factors but combustion pressure is related to power/torque, and the smaller the turbo generally the higher the intake temp for any given power level. If it is combustion pressure then people should be more worried about power level being the factor that makes you stop due to fear of detonation, eg a a gt35 running 15psi etc.

I am not sure as I don't have first hand experience tuning motors. Are engines more likely to det due to intake heat from being out of efficiency range, or more likely to det because of pure combustion pressure? An example if tuning on BP98 is it just simply hard to get over xkw due to detonation? or is it a matter of temp, so you can make 1000hp on an rb25 on bp98 as long as you get a turbo that is efficient and cool at that power level?

Bit of a ramble but does that make sense?

[SargeRX8]

Tao would suggest the main killers with these turbos are a poor intake and poor exhaust. The poor intake(small intake pipe, shit intercooler etc) will cause flow restrictions and the intake temps will be hotter, resulting in potential detonation. A restrictive exhaust will cause the turbo body and manifold to get very hot as it can't push fumes out, this increasing the EGT's and this plays a big role in detonation. If you have a turbo capable of 400hp and you are making 400hp at your engine on 98 fuel, you are at the limit of the turbo. Any higher will just create heat. Running the car on race fuel or E85 will raise the bar.

If you have a turbo capable of 1000hp and an Rb25 which isn't going to blow due to the massive combustion pressure(these motors have high comp ratio), and you can somehow factor out heat and flow out of the equation then I believe it will make your 1000hp.

[Rolls]

Yeah I understand how efficiency works, what I am asking is what is the main cause of detonation with everything being held constant, increasing intake temps, or increase combustion pressure (more air+fuel due to more boost).

[GTScotT]

The issue darren is talking about goes beyond detonation, he is saying the charge temps are getting to a point that takes its toll on an already tired engine

You need to remember that compression doesnt just whittle away over time like its just a number, it literally deteriorates as the condition of the motor does. Worn rings, worn bores, worn piston crowns.. Add more heat to the mix and you have yourself a motor waiting for the last straw.

I would say 140psi is the rough benchmark of 'worn' for most nissan motors Ive tinkered with. Most motors ive used at 130psi have died shortly after lol. I believe 180 is the highest it can be and 160 is about right for a healthy motor. They should be within 155-180 from new.

Once a turbo gets to its peak its also running pretty hot, as stated - cool for a healthy motor, not so cool for a tired one.

[Rolls]

I guess what I am asking, which setup is more likely to induce detonation out of these two hypothetical setups running a street fuel like BP98:

Hypergear turbo

24psi

250kw

out of efficiency zone, cooking the air

lower combustion pressure, greater temperature

big GT42 or larger

15psi

400kw

barely pushing the turbo, very efficiency and low temps

greater combustion pressure, lower temperature.

eg what is the dominating factor for detonation in an RB engine at these power levels, intake temperature, or combustion pressure?

edit: or have I gotten this wrong, and with the greater temperature the combustion pressure is similar between the two setups?

Edited January 15, 2012 by Rolls

[jet_r31]

The chance of detonation does go up exponentially with more boost, but I am of the opinion if you tune badly enough to blow it up at 22psi, then the motor has no chance at 18psi. The same level of care is required in both situations, the same safety margins are required.

What is the biggest factor for detonation at these sort of power levels, is it combustion pressure? Or is it intake temperature, I know both are major factors but combustion pressure is related to power/torque, and the smaller the turbo generally the higher the intake temp for any given power level. If it is combustion pressure then people should be more worried about power level being the factor that makes you stop due to fear of detonation, eg a a gt35 running 15psi etc.

I am not sure as I don't have first hand experience tuning motors. Are engines more likely to det due to intake heat from being out of efficiency range, or more likely to det because of pure combustion pressure? An example if tuning on BP98 is it just simply hard to get over xkw due to detonation? or is it a matter of temp, so you can make 1000hp on an rb25 on bp98 as long as you get a turbo that is efficient and cool at that power level?

Bit of a ramble but does that make sense?

Well EGTs have a big role to play aswell, a dyno can NEVER replicate real life, case in point my brothers gemini banged head gaskets every 1000km. Had a HKS 2540R on it 10yrs ago

on 23psi( read run flat out) the tune looked good on dyno but after thrashing on road or track the headgasket would go. The turbine wheel and exhaust housing where just to small to run flat out for any lenght of time and EGT's would go up and combustion pressure with it, water injection would have fixed that... Gt3082 now with .82.....no head gaskets eaten, and f**kloads more power.

i use to run a EGT gauge in my 99 wrx with 4 different turbos, i stock, 1 VF 22, one AVO 400 and one a GT3082. From 0- 250km, the stock turbo would get to 230km and the gauge was 800 and rising, with the 22 it rose to 650 and slowly kept climb, and the other to sat dead at around 650 and woudn't budge even held at 7600rpm and 275-280km in top gear for kilometres.

All safe, fat AFR's in the 11's

Once you switch to E85, methanol, water injection, you have more octane and less EGT's so everything changes again, even though you will make more power...

http://rusubaru.com/egts-101/

cheers

darren

Edited January 15, 2012 by jet_r31

[jet_r31]

I guess what I am asking, which setup is more likely to induce detonation out of these two hypothetical setups running a street fuel like BP98:

Hypergear turbo

24psi

250kw

out of efficiency zone, cooking the air

lower combustion pressure, greater temperature

big GT42 or larger

15psi

400kw

barely pushing the turbo, very efficiency and low temps

greater combustion pressure, lower temperature.

eg what is the dominating factor for detonation in an RB engine at these power levels, intake temperature, or combustion pressure?

edit: or have I gotten this wrong, and with the greater temperature the combustion pressure is similar between the two setups?

Well you sorta have to have a believable figure, but EGT"s( and they contribute to combustion pressure) and intake air are going to be lower with the 42..

But your also got to keep revs in mind, and how many, revs is worse at destroying a motor than boost pressure..

if you make 450rwkw at 6500 rpm and and another motor makes 370rwkw at 8000rpm, the one with more power will

generally last longer

cheers

darren

Edited January 15, 2012 by jet_r31

[Rolls]

Yeah empirical evidence suggests that intake temperature are definitely the dominating factor, hence ironically it might be generally safer to make 300kw+ with a big turbo than pushing these HG turbos to the max to make 280kw (with obviously far better response).

[jet_r31]

No might, it would be on 98 octane... there no question about it, E85 fixes that though ..lol

eg what is the dominating factor for detonation in an RB engine at these power levels, intake temperature, or combustion pressure?

Its always about combustion pressure... intake temperature/EGT/detonation/power level are just things that change it

cheers

darren

Edited January 15, 2012 by jet_r31

[Rolls]

intake temperature would have no effect on combustion pressure surely?

[Birds]

Temperature is related to air density, so I'd say it has effects on combustion pressure.

[Rolls]

yes higher temperature = less air for the same pressure hence smaller bang/combustion pressure.

So technically higher temperatures lower combustion pressure but it means a smaller increase in temperature is needed to reach autoignition temp though hence why higher intake temp charges can result in detonation.

[hypergear]

I've got some more sheets sent in today so I'll mention it.

Tuners I use in Melbourne are experienced. How ever some of others are lacking of skills. The tune made more difference then any thing else in terms of power delivery, response, drivability and reliability.

This is the same car that we did FNT comparison earlier. This is the difference between his original tune when he came in from ACT and final tune when he left Melbourne.

Red is his original tune, and Green is final tune. Note the original AFR in red. The car pined badly that we could not complete a dyno run.

If any one's result is substantially differ to controlled result assume all hardware are 100%. Check your tune map, and use my mine as reference. Ultimately drive your car in.

[Rolls]

Moral of the story, most tuners are rubbish.

[rondofj]

Moral of the story, most tuners are rubbish.

Hehe

[Harey]

Another Jeff with an R34 GTT with Hypergear turbo haha

A quality tune is absolutely essential!! I drive for an hour to get to Trent at Status.

[lilcrash]

Finding a good tuner is hard, but finding one who actually wants to do it properly everytime is even harder.