New Developments in Supra Turbo applications?

[James]

That's why I'm an advocate of small singles. A VVTi lump with an efficient, small, modern turbo and decent management can give you an extremely fast road car that is reliable and offers decent cruising economy.

 

I need to stop popping by these threads due to posts exactly like this

 

I do wonder what it'd be like to change out the T88 for a GTX35R or similar on my VVTi.

[Scott]

I need to stop popping by these threads due to posts exactly like this

 

I do wonder what it'd be like to change out the T88 for a GTX35R or similar on my VVTi.

 

Have you ever noticed the difference between night and day?

[thetrashcanman]

I wish I had bought the M135i in hindsight instead of the Supra! Alas I'm emigrating but the reviews of that car are outright amazing. The potential for the car too with the N55 setup. Amazing. You enjoying it Gaz, any flaws?

 

Is it bad that I'm looking at then 12 plate 8 speed autos are around 22k which is amazing value in my opinion, only problem being a BM I reckon will depreciate like a stone.

[Nic]

Not at all. My GT35R single was faster across the board. A newer, Garrett GTX30R would still give you 500hp, be noticeably faster spooling, and provide decent top end. In all honesty though, top end power on road cars (certainly in the UK) should be a secondary concern to a decent, low down torque curve IMO.

 

[Scott]

Is it bad that I'm looking at then 12 plate 8 speed autos are around 22k which is amazing value in my opinion, only problem being a BM I reckon will depreciate like a stone.

 

A stone weighed down with an anchor.

[Ian C]

I still dream of fitting a GTX3576R one day, that's my idea of the best compromise between lag and power. Bit expensive though when I've got a perfectly working turbo already. And a wife

[Sheefa]

Is it bad that I'm looking at then 12 plate 8 speed autos are around 22k which is amazing value in my opinion, only problem being a BM I reckon will depreciate like a stone.

 

If I had the choice again and I was staying here I would get one in a heartbeat. Bugger the looks its a proper drivers car. A few remaps being released now too with 370bhp and over 410lbft.

 

I reckon it would teach all the hot hatches and most sports cars a thing or two. Check these out:

 

[video=youtube;lU1nZ0-oX9k]

[Ian C]

I had to fathom out how the BMW diesel sequential turbo system worked once due to a friend of mine having both of his expire after a rear-end impact (yes, it can happen, was great fun CSI'ing that one).

 

If you remove any turbo flow sizing issues and any concerns about material temperature strength, I reckon some of the more adventurous of us could retrofit that setup to a 2JZ and control it with a Syvecs

[Jellybean]

Some info from Supra Forums, I didnt realise the engine head was so advanced

 

The BMWs performance has a lot to do with the engine not just the turbos that are on it. The 2J is ancient technology compared to the newer BMW straight six engines, dual variable valve timing, valvetronic sytems, direct injection and so on.

 

MW has gone one step further and re-designed the V8. They've moved the exhaust valves and outlets on the inside of the cylinder heads thus making a shorter path for a spontaneous response.

 

Their latest turbo development has been to utilize the "scavenging effect" and pair up the cylinders so that the exhaust pulses don't interfere with each other. In other words only 2 non-interfering cylinders per each path. In theory this produces a very efficient and smooth spool of the turbos. The BMW M5 F10 S636Tu gas powered V8 Twin Turbo develops 500ft/lbs at 1500RPM!...and maintains 500ft/lbs torque to apprx.5800RPM!

 

http://m-power.com/imageDispatcher.jsp?folder=varlink2&image=thumbs/Open_2516_5896.jpg

[Littler]

Could you use variable geometry turbo's on the 2JZ? A bit like what Ryan did with his V8, has no wastegate and the fins on the A/R adjust (smaller to bigger so to speak) to allow the quick response low down but then not being restrictive at the top end as the open up. Very similar technology to that in the 911 turbo's and GT2 cars.

[Gaz6002]

Could you use variable geometry turbo's on the 2JZ? A bit like what Ryan did with his V8, has no wastegate and the fins on the A/R adjust (smaller to bigger so to speak) to allow the quick response low down but then not being restrictive at the top end as the open up. Very similar technology to that in the 911 turbo's and GT2 cars.

 

There's no reason why not, except the setup and development costs. I've often thought that would make a great road car.

[Littler]

There's no reason why not, except the setup and development costs. I've often thought that would make a great road car.

 

Exactly my thoughts, the cost aside, it would be the best of both worlds

 

And I suppose in theory this could be applied to a single turbo application rather than twins too as you'd have a turbo that would adjust from a small A/R to a larger A/R (with the same wheel size though I'd guess).

Edited September 18, 2013 by Littler (see edit history)

[Gaz6002]

Exactly my thoughts, the cost aside, it would be the best of both worlds

 

Yep, virtually no lag is a very attractive prospect! I suspect packaging may be an issue, but then a big twin kit could probably provide a base.

[Nic]

The BMW M5 F10 S636Tu gas powered V8 Twin Turbo develops 500ft/lbs at 1500RPM!...and maintains 500ft/lbs torque to apprx.5800RPM!

 

500ft/lbs of torque at 1500rpm sounds good on paper but you're only going to be able to get a fraction of that actually through the tyres without them spinning.

[Kirk]

As complex as it may sound and with reasonably sized turbos, something like the size of VNT Tt28's, I don't see no reason why you couldn't mount one lower down than the other.

 

 

Granted it would take some very tricky manifold design but there is space for it.

[Scott]

500ft/lbs of torque at 1500rpm sounds good on paper but you're only going to be able to get a fraction of that actually through the tyres without them spinning.

 

My 535d doesn't have a problem with it. Even 2k RPM launches are fine from standstill, a bit of a wiggle but nothing crazy.

 

I was quite surprised to be honest, but good rubber and a good chassis makes all the difference.

[Gaz6002]

Decent traction control also makes quite a difference.

[Scott]

Decent traction control also makes quite a difference.

 

I wouldn't have it off when pushing the limits, but I have it off for launches and it's still no trouble

[Ian C]

The design and packaging of the sequential setup is pretty clever and elegant. With the BMW system to work from I still think a decent fabber could knock something up pretty quickly. There are only two actuators plus the wastegate one, and only one of those is on the hot side. There is some trick casting for the exhaust system but that's mainly for packaging reasons, we'd have twice the length of space to play with on the 2JZ hot side.

 

Yes the engine design is 20+ years old now, but that turbo setup doesn't work well purely because of fancy cylinder head port designs

[Digsy]

There's no reason why not, except the setup and development costs. I've often thought that would make a great road car.

 

High EGTs is why variable geometry turbos haven’t caught on in a big way yet in gasoline engined cars. Of course it all depends on how durable you want it to be.

 

I believe that Porsche and Maserati are the only OEMs using VGTs on gasoline production engines, compared to turbo diesels where they are virtually standard fitment.

[Gaz6002]

High EGTs is why variable geometry turbos haven’t caught on in a big way yet in gasoline engined cars. Of course it all depends on how durable you want it to be.

 

I believe that Porsche and Maserati are the only OEMs using VGTs on gasoline production engines, compared to turbo diesels where they are virtually standard fitment.

 

Yep, it's all about getting the mechanical components to withstand the heat. If they've managed it in the crammed-full 911 engine bay though... they use BW ones don't they?

 

Pretty much every single commercial vehicle I drive these days uses some form of VGT. Very interesting tech which I reckon will see more and more use as time passes.

[Chris Wilson]

Porsche have had some serious warranty claims on the VV turbos, from what I have heard.

[Scott]

500ft/lbs of torque at 1500rpm sounds good on paper but you're only going to be able to get a fraction of that actually through the tyres without them spinning.

 

 

I was just thinking about this on the drive home, what an exciting life I lead...

 

Torque vs RPM shouldn't make any difference to traction in my mind. It shouldn't matter if there is 500lbs rotating the rear wheel at 1500 rpm or 4500rpm... if the tyres aren't up to holding back 500lbs of accelerating torque then it won't matter at which point in the rev range this occurs.

 

Following on from that particular train of thought I started thinking about the relation of BHP in all this. In my mind I have simplified BHP as to how quickly the engine itself can accelerate. Low BHP cars take longer to accelerate, in neutral, than higher BHP cars. Obviously there are HUGE variables with regards to the internals but the basic analogy holds for me. If you think about revving an engine, the higher up the rev range you go... the quicker the revs increase. This is due to the BHP increasing as the revs increase. Chuck a turbo into the mix and it's hard to see what impact it has in neutral, but it's very evident when accelerating in gear.

 

So, with the above in mind, I can only guess that it's the torque combined with the rate at which the torque can be accelerated (BHP) that determines whether traction is lost or not. At lower revs the torque is there to create the rotational force, but the BHP is low and thus the acceleration of the engine is slow. This gives the cracking controlled pull that you get from low down torque monsters, yet a continued acceleration effect as the revs/bhp increases.

 

My oil burner is very quick at getting going, but the lack of BHP from the engine output keeps the rear wheels in check, obviously along with the tyres and compliant chassis. Oh, trucks are also a good example. They have 4 digit torque figures from neigh on 1000rpm yet they don't burnout when pulling away

 

Forgive me if I have just pissed all over the laws of physics, this is just how my brain interprets what's going on lol. It makes sense in my mind

 

Edit: I just thought of another example. If you rev a high torque diesel in neutral and time how long it takes to redline, then drive the car in first gear and do a pull.... there won't actually be much difference in the time the car takes to redline. This is because the torque isn't the limiting factor in the acceleration. The engine has enough grunt to physically accelerate the wheels round as fast as the engine can accelerate itself. The limiting factor is the BHP of the engine. Swap out the high torque diesel with a higher power, lower torque car and the opposite will be found, the car will accelerate faster from xxxx to xxxx rpm in neutral than it will in gear.

Edited September 18, 2013 by Scott (see edit history)

[dandan]

My 535d doesn't have a problem with it.

 

Your 535d make 500lbf.ft at 1500rpm? Sweet

[Chris Wilson]

"If you think about revving an engine, the higher up the rev range you go... the quicker the revs increase."

 

 

Hmmmm.....