Big Single or Twin turbo upgrade??

[fredly]

hello to all , i am interested in upgrading my gtr's turbos and i need some advice to whether i should go a big single or a nice size twin set up??. I want at least 400 at all 4 wheels and if possible can you guys give some adive to when the turbos would come on to boost??? any information will be greatly appreciated!!!

thanks :Bang: :Bang: :Bang:

[7heavn]

If you are talking 400hp at the wheels this can be easily achieved with a pair of nice low mounts such as n1's or 2530's at 1.2-3bar on pump fuel in a GTR You will also have the same response down low as the stock turbo's and the car will be a pleasure to drive on the street .

Big singles are good for making big peak power and also the underbonnet wow factor but cruising around the street you will have no were near as much response as with the low mounts . When it all boils down for a street GTR low down and mid range response is what it's all about as I rarely wind my car right out on the street soppose it's why I've kept my license all this time .

[HIPSI]

Guess it depends what kind of performance your after. Personally im going for a large single turbo. Engine rebuild with a higher rpm redline would really be needed to get the best out of it though. Twins would be great for response but a large single will give you that "time to go home and change the underware" kinda feelin!! :wassup:

[slow13dude]

Guess it depends what kind of performance your after. Personally im going for a large single turbo. Engine rebuild with a higher rpm redline would really be needed to get the best out of it though. Twins would be great for response but a large single will give you that "time to go home and change the underware" kinda feelin!!  :wassup:

Well that's why the GTR has twin turbos anyway isn't it - for responsiveness. The ceramic turbine wheel was chosen for responsiveness, not absolute power?

[T88 ON BOARD]

Go a big single...T78 or T88 get the smaller version though the T88-33D you will see boost Around 5400-5600rpm On the stock motor...Although 272* cams were used, cooler, etc etc...

Mods would vary when the turbo comes on...

Its a simple set up you can get one between $4500-5500 depending on condition...

And you get the awesome wastegate scream

As for the power you will easily pull over 400KW@all 4 wheels considering the mods etc....

[pnblight]

If you are talking 400hp at the wheels this can be easily achieved with a pair of nice low mounts such as n1's or 2530's at 1.2-3bar on pump fuel in a GTR   You will also have the same response down low as the stock turbo's and the car will be a pleasure to drive on the street .  

Big singles are good for making big peak power and also the underbonnet wow factor but cruising around the street you will have no were near as much response as with the low mounts . When it all boils down for a street GTR low down and mid range response is what it's all about as I rarely wind my car right out on the street soppose it's why I've kept my license all this time .

7heaven is spot on the mark

90%plus of your driving will be at lowish speed(below110) and lowish revs, general driving so its nice have a car that is a pleasure to drive normally, as well as a monster when you leen on it.

Go twin r34 N1 or hks2530 you'll never regret it :wassup:

[600hp]

go the low mounts its like driving a car with more capacity with the improved torque.

have you been in a GTR with 300kw because thats heaps, and its mad fun.

[180bfj20det]

I think that most of you dont actually realise that gone are the days where two smaller turbos give better responsiveness than one. Physics will also support this fact and sorry to those who want to try and argue against it, because physics can't be changed. The fact is, with two turbos you have twice the loss energy required to spin the turbine, leaks, twice the oil getting into your compressed air (since no turbo is 100% seal-proof). OK, since they're smaller turbos (compared to lets say one big one), the losses will be smaller through each turbo, but not combined. That taken into consideration, it is impossible for two small turbos to be more responsive than one larger turbo which of the same horsepower rating of the two turbos combined. Now you may argue against this, and I will most likely take your side if you chose to implement the T88 or T78 as your examples. These are old-school plain bearing pieces of crap which make the horsepower only in the big revs. The reason is because they are old school crap turbos. These days we have BB turbos and gone are the days where two is better than one for responsiveness. You can see that this logic has been adpated to by in commercial cars. Take the new subaru B4 for example. Its predesessor had two sequential turbos for responsiveness. Now it only has one BB making more power, more response (yes power ealier) and more mid range power. There is a GTR going around that exploits this very fact too. It has a single BB GT30 and runs in the tens with no loss in drivability, certainly less than a pair of 2530s. Twin is old school and you only ever need to run twin if one BB turbo cant provide you with the power you want. Considering garette make a BB 1000 hp turbo, that rules out most cases. This is my experience anyway. But before you hammer my comments, ask yourself if you have ever driven a GTR with a GT30 and compared its drivability to something with twin turbos that can also do 10s.

[600hp]

over 500 kw at all our has been made with 2540's and nos at CRD.

[pnblight]

I think that most of you dont actually realise that gone are the days where two smaller turbos give better responsiveness than one. Physics will also support this fact and sorry to those who want to try and argue against it, because physics can't be changed. The fact is, with two turbos you have twice the loss energy required to spin the turbine, leaks, twice the oil getting into your compressed air (since no turbo is 100% seal-proof). OK, since they're smaller turbos (compared to lets say one big one), the losses will be smaller through each turbo, but not combined. That taken into consideration, it is impossible for two small turbos to be more responsive than one larger turbo which of the same horsepower rating of the two turbos combined. Now you may argue against this, and I will most likely take your side if you chose to implement the T88 or T78 as your examples. These are old-school plain bearing pieces of crap which make the horsepower only in the big revs. The reason is because they are old school crap turbos. These days we have BB turbos and  gone are the days where two is better than one for responsiveness. You can see that this logic has been adpated to by in commercial cars. Take the new subaru B4 for example. Its predesessor had two sequential turbos for responsiveness. Now it only has one BB making more power, more response (yes power ealier) and more mid range power. There is a GTR going around that exploits this very fact too. It has a single BB GT30 and runs in the tens with no loss in drivability, certainly less than a pair of 2530s. Twin is old school and you only ever need to run twin if one BB turbo cant provide you with the power you want. Considering garette make a BB 1000 hp turbo, that rules out most cases. This is my experience anyway. But before you hammer my comments, ask yourself if you have ever driven a GTR with a GT30 and compared its drivability to something with twin turbos that can also do 10s.

there is one thing your missing Graham bell explain it better than me in Forced induction , its a fact they discovered then forgot and discovered again , i will try my best to explain in my terms

The clearer the exhaust pulse signal ,the more efficient the turbo will spool

(by thing less cylinder per turbo more efficient)

this is not an ideal i made up but a stated fact from published documentation as Graham Bell talks about in his book and i believe this is why all top level turbocharged car were twin turbo and why F1 never used single turbo configuration.

Please just passing on what i have read for on the subject

[RedRocket]

As far as I know most upgraded twins dont make full boost till 3000rpm or higher.

My single GT35R made full boost at 4000rpm.

Good for up to 500rwhp, cheaper, simpler and lighter.

I like having two power modes: the one without boost to drive around

local streets in stealth mode, and a nice wide top half for other occasions.

At least the RB26 has enough torque off boost to get around at a respectable pace.

Huge huffers that dont happen till 6000+ would be just plain annoying though.

[R31Nismoid]

a TT engine bay can be a bit tight... if you want to do work yourself etc.

a big single opens up things a bit more.

just another thing to consider if your the DIY person.

I tried removing my own low-mount (big single) what a mission. If it was high-mounted i'd have had it off in under an hour.

[slow13dude]

I think that most of you dont actually realise that gone are the days where two smaller turbos give better responsiveness than one. Physics will also support this fact and sorry to those who want to try and argue against it, because physics can't be changed. The fact is, with two turbos you have twice the loss energy required to spin the turbine, leaks, twice the oil getting into your compressed air (since no turbo is 100% seal-proof). OK, since they're smaller turbos (compared to lets say one big one), the losses will be smaller through each turbo, but not combined. That taken into consideration, it is impossible for two small turbos to be more responsive than one larger turbo which of the same horsepower rating of the two turbos combined. Now you may argue against this, and I will most likely take your side if you chose to implement the T88 or T78 as your examples. These are old-school plain bearing pieces of crap which make the horsepower only in the big revs. The reason is because they are old school crap turbos. These days we have BB turbos and  gone are the days where two is better than one for responsiveness. You can see that this logic has been adpated to by in commercial cars. Take the new subaru B4 for example. Its predesessor had two sequential turbos for responsiveness. Now it only has one BB making more power, more response (yes power ealier) and more mid range power. There is a GTR going around that exploits this very fact too. It has a single BB GT30 and runs in the tens with no loss in drivability, certainly less than a pair of 2530s. Twin is old school and you only ever need to run twin if one BB turbo cant provide you with the power you want. Considering garette make a BB 1000 hp turbo, that rules out most cases. This is my experience anyway. But before you hammer my comments, ask yourself if you have ever driven a GTR with a GT30 and compared its drivability to something with twin turbos that can also do 10s.

If you say so. Anyway at this point the RB26DETT is "old school" because it's out of production.