Single (t51r) Vs Twins (t517z)

[GTR 94]

ok all well i never really post this sort of stuff up but as my circumstances in the near future may be changing i thought id post some information up for people trying to decide on running twin turbo setups or big singles. this info is all on a 93 R32 GTR still running 2.6lt capacity.

well some of you guys would know this car but it is not very often seen on the road . it started of as running twin T517Z's with 8cm rear housings and small cams in a full house engine, but then after destroying an N1 oil pump the motor was taken out and the twins gotten rid of, it then had a HKS T51R SPL BB with 1.2 rear housing (which i think is from the T62R) took there place.

The car with the twins made 320 RWKW on 20 pound with very safe tune it had tomie pon cams, standard plenum, a power FC, nismo AFM and still running the standard R32 GTR intercooler. the power delievery was very strong and as you can see in the dyno sheets came on quiet early. (green line high boost - blue line low boost)

The car now runs alot bigger cams, Trust plenum, Autronic plug in for GTR ECU and a Trust 115mm Drag intercooler it is still running a very safe tune and makes 375RWKW on 20 pound. the car makes plenty of power but as you can see from the graph does not come on till very very very late.

im pretty sure both runs were done in 3rd and both on pretty mild temp days 25-28 degree days, and all on PUMP fuel 98oct.

well ask any questions and ill try to answer them the best i can please dont ask if its laggy cause the answer is YES also dont ask when it comes on boost, look at the graph go out side drive your car and see what your reving at when your at the speeds that it comes on.

Id just like to thank Shaun Frendo from ERP Melbourne Victoria for building one of the strongest RB's put together

[LTHLRB]

can you throw up a pic with boost and power with the t51r.. just gives more of an indication on when you come onto boost

bet this thing makes your neck hurt when power comes on lol

[R31Nismoid]

Did you only have 320rwkw with the 517s Lee??? i didnt know that! I thought it was more!

I remember Jack had closer to 360-370rwkw on about 22/23psi from memory.

[Swiper the Fox]

t517z's make 220kw at 120kph...t51 makes 65kw at 120kph

[Dale FZ1]

The phrases "power density", and "area under the curve" spring to mind when seeing the results.

What were your goals when making the change?

[Swiper the Fox]

  Dale FZ1 said:

The phrases "power density", and "area under the curve" spring to mind when seeing the results.

What were your goals when making the change?

there is an obvious lack of headwork apparant...or the correct type of headwork

[dangerman4]

  DiRTgarage said:

t517z's make 220kw at 120kph...t51 makes 65kw at 120kph

either the rev limit has been changed drastically or,

that ones in 3rd and ones in 4th?

Edited January 16, 2009 by dangerman4

[Lithium]

Thanks for sharing that info, but I'm sortof missing what the point proves - you are comparing a turbo setup suited to 700hp with a turbo setup suited to 1100hp and saying "Look!! The 1100hp setup is laggier!". It has nothing to do with twins vs singles, with a pair of T67-25Gs on I'm sure the result will be similar.

Running the runs with completely different gear ratios just makes it that little bit more pointless - interesting dyno plots, but not in the teeniest bit informative on the whole twins vs single topic.

[paulr33]

i dont get it - why would you go from a twin setup with response city

to a big single 1.2 rear - what were expecting????

*confused*

[T04GTR]

interesting info but im sure the sound makes up for the response

[GTR 94]

  LTHLRB said:

can you throw up a pic with boost and power with the t51r.. just gives more of an indication on when you come onto boost

sorry cant, this is the only dyno sheet of got, once its fully tuned ill post up a sheet with other indications.

  R31Nismoid said:

Did you only have 320rwkw with the 517s Lee??? i didnt know that! I thought it was more!

I remember Jack had closer to 360-370rwkw on about 22/23psi from memory.

na that was it, never really was tuned fully but still went awsome, i think Jack may have had the 10cm rear housings though? cant remember but were still great turbos.

  Dale FZ1 said:

The phrases "power density", and "area under the curve" spring to mind when seeing the results.

What were your goals when making the change?

to be honest there were no real goals it was sort of a snow ball effect, and more to the story like the turbo was at the right price so why not give it a try which turned into what it is now.

  DiRTgarage said:

there is an obvious lack of headwork apparant...or the correct type of headwork

?please explain? by looking at the graph do you think the head has not had any work? or not the correct work?

  Lithium said:

Thanks for sharing that info, but I'm sortof missing what the point proves - you are comparing a turbo setup suited to 700hp with a turbo setup suited to 1100hp and saying "Look!! The 1100hp setup is laggier!". It has nothing to do with twins vs singles, with a pair of T67-25Gs on I'm sure the result will be similar.

Running the runs with completely different gear ratios just makes it that little bit more pointless - interesting dyno plots, but not in the teeniest bit informative on the whole twins vs single topic.

sorry might not have explained my point properly, when i say twins i mean low mount still. not many people go for twin high mount set ups that i know of, all im trying to show is that twin low mounts do come on earlier and thats it and im sure lots of ppl are aware of this BUT you would be surprised at how many ppl ask "is it very laggy?" and to be honest it shits me of course it is so now they have a comparison. that is all.

if you think the thread isnt the"teeniest bit informative" then dont read it.

[GTR 94]

  paulr33 said:

i dont get it - why would you go from a twin setup with response city

to a big single 1.2 rear - what were expecting????

*confused*

hey Paul yeah i know pretty weird , but like i said it was one of those things the engine had to come out because of the oil pump and the 51r was there, so why not try it.

  T04GTR said:

interesting info but im sure the sound makes up for the response

yeah cant beat the whistle on it you watch ppl looking in the sky as you come past scares some into the emergancy lane sometimes "i do apologies for that"

[Daz]

So what do you prefer the response of the twins or the kick up the arse the t51r gives you?

[Al]

I think what people are trying to say is that: You sacrificed sooooo much response and usable power for so little power gains.

It just doesn't sound right. You mentioned you have a 1100hp set-up, so why is it only making 500hp?

I know an rb25 with a to4z making 360rwkw on pump fuel at 20spi

or

an rb30et with a 1000hp turbo making 420rwkw at 22psi, on pump fuel.

I do understand that these turbos really wake up at about 30+psi, especially when using C16, but your figures really sound low.

My question is; which set-up do you really prefer to drive?

*edit: Damn Daz just got in b4 me *

[JAGR33]

Hey Lee,

I definetly had the 8cm version and most power i made with the t517z turbos was 365rwkws...

Seeing your car at the show and shine with the BFT (big fu(koff turbo) i thought this car has come along way since i last saw it...

At the end of the day it something you had to try and its not the end of the world, if your not happy with the lag swap it for a smaller turbo and you should still have the same peak power but shitloads more midrange...

And remember dynos are tuning tools..... all dynos are different....

Cheers,

Jack

[R31Nismoid]

Al - even 360 @ 20psi sounds low

430-440rwkw from 24/25psi from ... Adam i think it was (yellow 33 gtr)... but then that was a fairly $$ motor

[Blue32]

My built motor with T517z 8cms makes 402rwkw on pump fuel with 1.5bar........bloody responsive and very large useable rev range for the circuit....

[Lithium]

  GTR 94 said:

if you think the thread isnt the"teeniest bit informative" then dont read it.

You can't know if its going to be without reading it!

[Swiper the Fox]

  GTR 94 said:

?please explain? by looking at the graph do you think the head has not had any work? or not the correct work?

you can actually get T51R's to make power earlier...but it takes a fair bit of experience and r & d. Ive seen what we thought the was perfect set-up (made 500AWKW at 25psi on 98 pump fuel) come alive 1000rpm earlier and made another 50AWKW with a different approach to the port work and camshaft change.

Edited January 16, 2009 by DiRTgarage

[Daz]

  Al said:

I think what people are trying to say is that: You sacrificed sooooo much response and usable power for so little power gains.

It just doesn't sound right. You mentioned you have a 1100hp set-up, so why is it only making 500hp?

I know an rb25 with a to4z making 360rwkw on pump fuel at 20spi

or

an rb30et with a 1000hp turbo making 420rwkw at 22psi, on pump fuel.

I do understand that these turbos really wake up at about 30+psi, especially when using C16, but your figures really sound low.

My question is; which set-up do you really prefer to drive?

*edit: Damn Daz just got in b4 me *

I think a 35r or to4z would have been perfect for me but I like the wank factor....