Hypergear Turbochargers and High flow Services Development thread

[hypergear]

Torque delivery and driving ability is a major concern when designing new turbochargers, you can keep on posting in this thread. I will index it on the front page.

[GTScotT]

Scott how do the JZs compare to the crappy RBs?? RB25 and up. Heaps more down low or not that much difference??

The RB is pre built with suicidal tendencies in my eyes. The oil related issues they have is just nonsense. Here is my brief decision matrix for the JZ swap based on a 400kw setup:

RB-

Crank collar needed

AM oil pump needed

Head restrictors needed

External drains desirable

Valve springs needed (RB25 in specific)

Pistons/rods/overall good quality build needed

Gearbox not up to the task

JZ

Factory capable (oil system, pistons, rods, general make up - no expensive builds needed)

Cheaply replaced in failure

R154 gearbox IS up to the task

Forward facing plenum from stock

Probably 20kw shy on peak figures (resolved with 2psi more boost)

1.5JZ (3L conversion) cheaper and less involved than RB30 conversion

Conversion cost was similar to sale price of all RB related spares (I do my own fab and build)

Two further items for consideration:

1. 1700kg auto Soarer's can be seen running 11s on the factory turbos and factory stall converter. That's no fluke, that's a motor that likes to make some power.

2. I seem to have a knack at squeezing the lemon.. The RB, IMHO, is a lemon that does not like to be squeezed in factory form.

And yes, I have said it before. In hind sight the crappy RB does bolt in from factory and Stao's SS series turbos change the game for me entirely. If I had the opportunity again I would have done a quick refresh on the factory motor with some valve springs and run an SS-1. Now its back to SR, let the good times (and good power delivery) roll!

[Rolls]

Hmmm I have a couple of hypotheticals that may support Rolls' peak torque argument here. Will post tomorrow when I have time, but should we continue in this thread or another one? It's an interesting topic.

Make a new thread, I'm curious what other people have to say that haven't seen this thread.

Edited July 20, 2011 by Rolls

[Tangles]

Stao - perhaps purchase a 'smog pump' from USA and bolt it up to the intake (pushing air down the air filter), run it off an AirConditioner motor.

Becomes a supercharger of sorts.

[wisey18]

I'm definitely interested in this new prototype you're currently working on now Tao. I wanted something that was inbetween the SS1 and SS2 and this sounds like it's it. Good luck with it Tao. Hope it comes out as expected

[jjman]

All of these arguements are correct (quoted a few of them below for illustration's sake) but you are also missing one key ingredient in this as to why torque is more likely to create wheelspin when there is a spike in torque, also why sometimes it does and doesnt produce wheelspin even when there is a spike in torque.

Again- mothor of a thing to explain but here we go...

The missing variable here is the suspension.

A fast increase in torque (for those still confused on this just call it power but those of you who know it is to do with torque specifically) will not be able to give the suspension time to compress with the force, creating weight transfer and pressure on the tyres, and thereby create traction. So essentially there is less pressure on the tyres, which means there is less available traction.

this is why 'softer' (in a simple manner of speaking) suspension is better for straight line traction (unless you have drag spec tyres and a wheelie bar) because softer suspension is in fact delivering more pressure on the tyres under acceleration in a straight line.

so essentially as long as the suspension is able to compress enough to create sufficient force on the tyres to make traction then even large spikes in torque (power) occurring will not create wheelspin. The bottom line is that it is more likely to create wheelspin because it is giving the suspension (and tyres which are a part of the suspension) less ability to take up the force and create traction.

This is given in a real world example by Harey (quoted immidiately below) and how it relates to how the suspension is able to cope with the force being given to the tyres.

Having said all this, it is still a bigger issue than all of what is captured here due to all the INTERACTING aspects of physics that have already been highlighted plus even more- you want a real head-f*k then throw in later/cornering forces into the equation.

But the bottom line is that you do indeed need to understand the difference between torque and power to truly understand how it works.

Beyond this, if you want a real interesting read on some aspects of this and also in particular how the tyre is working in this equation look up the development of the 'big bang' motors in MotoGP. This principle basically revolved around the fact that they found more traction by NOT having even firing intervals by the pistons but firing (on a 4 cyclinder motor) a couple of pistons in closer order (say at 90deg and120deg ), then a big gap then the next 2 firing at 220deg and 250deg... ON the surface of it peak torque was higher but the truth lay further below in how it was generating more traction. It even confused the shit out of the traction engineers/scientists for a while

Its probably a crude example but say a clutch drop as opposed to a good launch at the same rpm. The peak torque is the same, the only difference is how sudden the torque changes.

Can someone give a scientific reason why this is so? I'm not convinced.

There is a limit of grip the tyre can provide, the only force acting on the tyre is the torque turning it, I don't see why a fast increase in torque would cause this?

I can see why fastly increasing torque might be conducive to wheel spin, but it in itself won't cause it. Eg you break traction with x torque, the wheel spins increasing rpm which also increases torque hence it spins faster. If you have flat torque it will not continue to spin like this, however if the torque value is enough to cause the wheel spin in the first place it will still cotinue to spin, it just won't smash the limiter like a steep torque curve would..

If the torque curve is dropping off and x torque causes it to spin, the increase in rpm would cause the torque to drop and hence stop the tyre spinning, but if it doesn't drop below the value required to spin it in the first place, it will continue to spin.

edit: That was confusing to write lol.

Without going into the physics of it, as I CBF to look up the formulas.

Torque is force, traction is force. The 1400kg car car only accelerate at a certain rate FROM a certain speed with its given variables (tyres suspension etc etc etc).

At a given point the rotating effort from the tyres (torque) will overcome the traction to the road. A sharp rise while it is already spinning will cause it to try and accelerate faster and with the additonal force it will overcome the available traction.

Think of traction as KG per square CM from tyre to road, how much force to you need to break the traction? Like the handbrake, yeah it will hold the car from rolling away, but the motor can overcome the force on the little handbrake shoes if you try hard enough cant it? Is it the increase in engine RPM that will make you break free of the handbrakes hold or is it more specifically the torque (ala FORCE) of the motor that will force the wheels to move?

Think about it dude...... Its physics.

I did and it isn't correct, it is the actual torque value that causes wheel spin, not whether it is increasing or not. If it increases steeply it is more likely to maintain wheel spin and not a single chirp though which is what I think you are getting at.

read my edited post.

If you are accelerating at X rate with your torque building at Y rate then why would you not impact the variable of traction if your Y rate increase significantly from your X rate that it previously was?

Think about it logically. You can accelerate as fast as the force you apply vs the amount of traction you have, your traction is constant, a sharp rise in torque (AKA FORCE) is NOT constant and will require more traction that your not getting any more of.

Edited July 20, 2011 by jjman

[Rolls]

yeah all of these arguements are correct (quoted a few of them below for illustration's sake) but you are missing one key ingredient in this as to why torque sometimes does and does not produce wheelspin. Again- mothor of a thing to explain.

The missing variable here is the suspension.

A fast increase in torque (for those still confused on this just call it power) will not be able to give the suspension time to compress with the force, creating weight transfer and pressure on the tyres, and thereby create traction. So essentially there is less pressure on the tyres, which means there is less available traction.

this is why 'softer' (in a simple manner of speaking) suspension is better for straight line traction (unless you have drag spec tyres and a wheelie bar).

From what I read the tyres ability to deform was just if not more important than the suspension. As how much time the tyre has to deform influences its coefficient of friction, for the same reasons as you explained with the suspension.

So in a perfectly simplistic model rate of torque wouldn't be an issue and instantaneous torque would be all that mattered (where I was going wrong in my first post), but when you include dynamic things like suspension and tyres it becomes extremely important (eg the real world).

Good post.

Edited July 20, 2011 by Rolls

[rondofj]

The RB is pre built with suicidal tendencies in my eyes. The oil related issues they have is just nonsense. Here is my brief decision matrix for the JZ swap based on a 400kw setup:

RB-

Crank collar needed

AM oil pump needed

Head restrictors needed

External drains desirable

Valve springs needed (RB25 in specific)

Pistons/rods/overall good quality build needed

Gearbox not up to the task

JZ

Factory capable (oil system, pistons, rods, general make up - no expensive builds needed)

Cheaply replaced in failure

R154 gearbox IS up to the task

Forward facing plenum from stock

Probably 20kw shy on peak figures (resolved with 2psi more boost)

1.5JZ (3L conversion) cheaper and less involved than RB30 conversion

Conversion cost was similar to sale price of all RB related spares (I do my own fab and build)

Two further items for consideration:

1. 1700kg auto Soarer's can be seen running 11s on the factory turbos and factory stall converter. That's no fluke, that's a motor that likes to make some power.

2. I seem to have a knack at squeezing the lemon.. The RB, IMHO, is a lemon that does not like to be squeezed in factory form.

And yes, I have said it before. In hind sight the crappy RB does bolt in from factory and Stao's SS series turbos change the game for me entirely. If I had the opportunity again I would have done a quick refresh on the factory motor with some valve springs and run an SS-1. Now its back to SR, let the good times (and good power delivery) roll!

Man this is pretty sad, I mean I love my Neo 25, to think the JZs basically JiZZ all over our poor RBs, lol hahaha, this is a pretty sad day for Nissan, everyone knows that Toyota's engineering and build quality is top notch and second to none; IMHO Nissan would be second then maybe Honda...

[Rolls]

They are fine for what they built them for, stock power levels.

[rondofj]

yes but who keeps these motors stock??

[jjman]

From what I read the tyres ability to deform was just if not more important than the suspension. As how much time the tyre has to deform influences its coefficient of friction, for the same reasons as you explained with the suspension.

relatively yes.tho one cannot work well without the other working well and its a strange reciprocal relationship

which brings us to an interesting point. We all know that our love for low profile tyres ruins our traction right?

if current trends were still that massive sidewalls were cool we would all have way more traction... Look at F1 cars and drag cars. Not much low profile action going on there...

however all of this is thrown on its head by the nature of all of these forces INTERACTING with each other. So basically having traction in cornering is something that is f*king with the equation for having traction in a straight line, so often things are a compromise making the best of forces in other equation meaning a reductoin in performance in another area. SO for grip in motorsport this includes braking, cornering (high speed corner grip, low speed corner-grip), acceleration (low speed acceleration, high speed acceleration), stability (straight line and corenering), turn-in etc etc etc. And all of these elements are often having to compromise for a gain in other areas. Then you throw in the motor's characteristics and whether it is smooth or has spikes in torque and the calculation of all these elements starts again. And again for differnet tracks and and, well you get the idea.

All this is the reason Rossi cant make the Ducati bike go faster... Their balance of these equations isnt as good as other bikes/riders/teams.

[Rolls]

Yeah I've tried telling that to people a lot of times, same with the softer suspension = more traction.

[hypergear]

If my drawning works then we should have 270~300rwkws with stock turbo's response and factory driving ability. With every thing bolt on and stock looking of course.

The ATR43SS-1 PU version is installed this morning. I only took it for a test drive based on my old tune. It feels like a huge turbo with babe turbo's response. Its got this really big pull under throttle, I haven't give it much yet, but very new driving experience, will have a interesting result soon.

Also you are all welcome to discuss engine changes and torque plus etc in this thread as they would all some sort related to a turbo, I will index them all on the front page making it easier to locate your discussions.

[petero'nell]

So what does this new turbo drives like compare to the SS1 that I just bought?

[hypergear]

So what does this new turbo drives like compare to the SS1 that I just bought?

I'm not sure what the dyno says yet. Feels like a 3540 comes in full boost at 3000rpms. Its got a crazy pull when you give to it. Compare to SS1 it feels like it has pickedup heaps more torque through out rev range with similar sort of response. But once again the tune in it now is for a much larger turbo so not sure what it feels like once its fully tuned. Will post up results.

Add:

Went for a 50kms drive, and its got even more responsive (probably got all the thick stabilizing oil washed away). Heaps of torque and zappy response. The best way describing it taking off would be: like a billet leaving the gun barrel. The car just launches, there is not a bit of flat spot down low or any where in the rev range.

As turbo builder I'm very happy with the way how it delivered power and torque. The drivability and performance worth every hour spent designing and making it.

[rondofj]

Wow, put this turbo out for production! !.. I buy..Hoping it will be same or lower price than ss1..

[Rolls]

Looking forward to dyno sheet

[wisey18]

Awesome results. Sounds very promising

[GTScotT]

Regretting now owning an RB powered tank anymore!

[SargeRX8]

Fizzle stick I wish I had that turbo now lol. Very keen to see 18psi at 3000rpm. Is the work you have performed on this turbo based on new turbo housing design or is it in the compressor/turbine wheel? What are the internals like? Damn lol, I would very much consider ripping the turbo off my car and paying for the compressor wheel fitted on if thats all it is!