Hypergear Turbochargers and High flow Services Development thread

[Rolls]

The bigger the torque spike the more of the push back in the seat feeling. As torque is proportional to acceleration.

The torque spike will be biggest with the smaller turbos running dickloads of boost, massive midrange spike.

[Birds]

I disagree with that...small turbos are more likely to come on early and give the car more low down torque but not a massive spike. Like the turbos used in turbo diesels, they aren't going to throw you back. And you can only run so much boost before it's outside it's efficiency range. Keep in mind we are talking about an RB25DET here, not a 2 litre. It's the big turbos that take forever to spool and throw on the power in the upper midrange...when they do it's a lightning bolt.

Anyway this "hold on feeling" is all subjective, no real point arguing it when to some people that's a turbo that holds strong throughout the range while others want a huge turbo to come on boost later and eat curbs.

[GTScotT]

I'm assuming you talking about 200kw turbos on SR motors? I found the 'push-in-seat' more epic in a couple of Jap spec s15s I drove with boost wound up high. But maybe thats because of the nature of the less torquey 4 bangers - lag.. then strong boost, RBs seem a lot mre linear and less crazy maybe because they already have the down-low torque pushing the car along..

Yeah my experience with the .86 I mentioned is on my SR. To be honest I consider a 2L 4pot to be more brutal in nature to a 6cyl of whatever size.

Whether it be some sort of lag and zap effect or that they actually product better torque for power is a difference of opinion really. I am happy for you to come and get an impression of my car once I change the exhaust housing. You will see there is no lag and zap effect but only a really strong pull effect through the midrange.

As a point of reference the TD05-18g SR I did recently made over 530nm on only 207kw, thats 300kw skyline material and it had peak torque at 4200rpm. I believe brutal delivery at a low RPM showcases actual torque, not that linear wind up toy feeling everyone normally misconceives as torque (pretty much what my setup has now, with 440nm at 5000rpm).

[Harey]

I reckon its the rate of increase of torque = crazy rush and quite often wheelspin.

Yes torque does give you the push in the back but if it is just slowly increasing then it doesnt feel like a rush. Remember someone posting about the LS7 Corvette ZR1 and saying it actually felt slower then his worked jap car with large turbo except when you looked at the speedo it would kill it. To me that is because the Corvette would have quite a flat torque curve whereas the jap car with large turbo would have no torque, no torque then a steep rise in torque.

[Birds]

Hahaha yeah but you're a drifter

For a street car just spinning your wheels at the wrong time can mean confiscation of your car for a month I think it is now.

I believe in Victoria it's now 25 to life.

[Rolls]

I disagree with that...small turbos are more likely to come on early and give the car more low down torque but not a massive spike. Like the turbos used in turbo diesels, they aren't going to throw you back. And you can only run so much boost before it's outside it's efficiency range. Keep in mind we are talking about an RB25DET here, not a 2 litre. It's the big turbos that take forever to spool and throw on the power in the upper midrange...when they do it's a lightning bolt.

I wasn't talking small turbos, just smaller turbos. Eg one of hypergears 280kw turbos is going to give a bigger torque spike than his lag monster 320kw ones.

Harey I agree with what you are saying, it is the spike that does it really.

Edited February 9, 2012 by Rolls

[GTScotT]

I reckon its the rate of increase of torque = crazy rush and quite often wheelspin.

Yes torque does give you the push in the back but if it is just slowly increasing then it doesnt feel like a rush. Remember someone posting about the LS7 Corvette ZR1 and saying it actually felt slower then his worked jap car with large turbo except when you looked at the speedo it would kill it. To me that is because the Corvette would have quite a flat torque curve whereas the jap car with large turbo would have no torque, no torque then a steep rise in torque.

I used to have this debate all the time with my old man. Theres an obvious point where usable torque comes into play, that being the happy area in your powerband. V8s feel linear because they make all their torque too early, its the energy of a big motor that makes them fast. But imagine you could harness all the wheel spinning torque they make at 200rpm and translate that to full traction acceleration... now that would be crazy.

The problem is there are sheer limitations of that sort of thing, like tyres and road conditions.. But thats where our little turbo toys come into play. We start with a boring little donk and add a turbo onto it. The right turbo and cam choice can shift the torque around to suit what gear ratios were limited by, and create a fast car.

I once built a front wheel drive turbo, most epic car I have ever owned. The theory of the turning wheels pulling you around a corner was a total win (driving wheels in a RWD point straight, so how can you expect it to propell you around a corner?). I set about finding the perfect balance between power and delivery to make the car really quick through the hills. I was finding as an NA it would understeer because it had not enough power or not enough energy in certain gears, but then the right cam/turbo choice ended up with only 120kw but a car that could punch through corners 2 gears above what it was prior (with the obvious speed increase to match).

End of the day its not all about how much torque or power or even where... But how its delivered. Said it before and will say it again, delivery is KING.

I believe in Victoria it's now 25 to life.

NSW is no different... been there, done that.

[Harey]

Yup for sure but I thought we were talking about the "power rush" not the fastest car through the hills. Now you are bringing fwd vs rwd into it as well.

[GTScotT]

Well arent you the pot calling the kettle black lol, Mr Corvette LS7 ra ra ra

Its all relevant anyway, were talking about the rush you get from certain turbos and if thats torque or just the 'feeling' it gives you. I did my best to eleborate on my theories by describing how I utilised this 'rush' torque feeling to better drive a car. Be it FWD or not. Trying to describe that the feeling is relevant to actual torque and speed.

About as relevant as comparing it to a V8 which Id say is entirely relevant in open discussion. Sorry if I didnt make my point clear enough, I hope I have now. Its hard to put everything down when at work.

[Hanaldo]

I agree with Rolls and Harey saying it is the torque delivery that you feel. My G3 only really comes on strong at about 5000rpm, and you get a little bit of a shove but nothing extreme. Most likely due to the lack of VCT. Comparing that to a mates 25 with an almost identical setup to me except with a smaller TD05, so less torque and less power, his turbo comes on song at about 4000 and it gives you a real shove. My car is still quicker, his just feels more brutal.

I need a retune dammit

[Josh_TypeX]

As a point of reference the TD05-18g SR I did recently made over 530nm on only 207kw, thats 300kw skyline material and it had peak torque at 4200rpm.

No it didn't... Power is directly related to torque. If it made 530Nm at 4200RPM it is making 233kw at 4200RPM.

[Manuel Kasko]

I just read all the replies so now I might ask you all a question

and also let you know what I was talking about when I mean "push back in seat"

So right now I am running a stock 33 with a greddy profec 2

Its running about 11PSI and bleeds to about 10PSI

When I take off in 1st and also putting my foot down in 2nd gear it gives me the rush feeling of I better hold on. No wheel spin or anything just that pressure that sits you in your seat

I was wondering if the SS1PU will do this but a fair bit harsher because its not a stock turbo or because the spool is close to the same as a stock turbo only the end result in kw gain changes?

Hope I am not to confusing guys

**edit** The car wont be stock when the SS1PU is installed it will have all the extras to get 250rwkw

Edited February 9, 2012 by Kasko

[Rolls]

I was wondering if the SS1PU will do this but a fair bit harsher because its not a stock turbo or because the spool is close to the same as a stock turbo only the end result in kw gain changes?

Hope I am not to confusing guys

**edit** The car wont be stock when the SS1PU is installed it will have all the extras to get 250rwkw

Yes it will do it harsher because it is making a solid 25-50% more torque in the midrange. I think this will be the best turbo for the feeling you want. I have a gcg turbo that comes on strong about 4k, and I describe it as the same thing, about 3.5-4k it just snaps you back in the seat due to the midrange, it then tapers off towards redline.

[Harey]

I agree with Rolls and Harey saying it is the torque delivery that you feel. My G3 only really comes on strong at about 5000rpm, and you get a little bit of a shove but nothing extreme. Most likely due to the lack of VCT. Comparing that to a mates 25 with an almost identical setup to me except with a smaller TD05, so less torque and less power, his turbo comes on song at about 4000 and it gives you a real shove. My car is still quicker, his just feels more brutal.

I need a retune dammit

Hahaha but thats not what I am saying. I am saying the G3 should give you much more of a rush due to the change in torque (steepness of the torque curve). The smaller TD05 should be quite a gradual build of boost whereas the G3 typically will be more nothing and then holy sh*t. You need to get your setup sorted so its like the latter

[Manuel Kasko]

Im so fricken excited for all the things happening to the car in the next few months!

When everyone was talking about the big laggy turbos making the feeling im looking for I was thinking about how I get the feeling from my stock one launches in 1st and and that surly isnt a laggy turbo

[Hanaldo]

Hahaha but thats not what I am saying. I am saying the G3 should give you much more of a rush due to the change in torque (steepness of the torque curve). The smaller TD05 should be quite a gradual build of boost whereas the G3 typically will be more nothing and then holy sh*t. You need to get your setup sorted so its like the latter

That's... Exactly what I said. Lol.

Most likely because of my lack of VCT, my G3 doesn't build torque very quickly. It still creates a lot of torque, but it's not a steep curve. My mates TD05 actually has a steeper torque curve, despite being more responsive. It makes less peak torque and less peak power, but the shape of his curve gives his car more of the rush.

Kasko, you need to be aware that the feeling you're after doesn't last, you do get used to it. Like you keep referring to your stock turbo giving the feeling you're after, yet if I was to go for a ride in a stock GTT I bet it would feel like I was in a Getz.

[Rolls]

A good way to reset that feeling is to have it off the road for 3 months, you forget what it is like completely, get back in it and go wholy shit this is ridiculous all over again heh.

[Hanaldo]

A good way to reset that feeling is to have it off the road for 3 months, you forget what it is like completely, get back in it and go wholy shit this is ridiculous all over again heh.

This is what I do Having another daily is great.

[GTScotT]

No it didn't... Power is directly related to torque. If it made 530Nm at 4200RPM it is making 233kw at 4200RPM.

No worries, DVS JEZ on this forum tuned it - he has the dyno data for it also

[DVS JEZ]

Heres my torque graph. Never noses over. Keeps climbing. Maybe we should all run small wastegates and let the boost climb the more the rpm increases.