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Location:
Gold Coast
Registered:
November 2002
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1JZ Turbo Position idea..Better than twin dumps??
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Thu, 14 November 2002 15:38
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Just like to know your thoughts on this idea....
Looking at the 1JZ i was wondering why it does not boost as well as the gtr, I know the twin dumps are good for a 1J but why not go the whole hog and:
Turn the rear turbo so they both face forward (like the gtr) and have some more direct decent plumbing getting rid of stock 1j crossback pipes and y pipes, im sure that plumbing is A reason for 1j's not to boost as hard.
The first problem is probably going to be the front dump pipe will be too close to the rear turbo's inlet causing excess heat but could modify rear manifold so turbo faces outwards a little.
Has anyone tried this yet with results...
The 1J plumbing is a bit suss Do u think...
Twin air filters,merged inlet pipe, twin dumps should make boost a little better,Make twins go to the end of the tranny .
What am i missing here....
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Thu, 14 November 2002 21:18
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Cos you'd still only have weak as piss stock 12a turbo's that wont flow.
for all the hassle get a big Single.
Matt
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Location:
newcastle
Registered:
June 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Thu, 14 November 2002 22:19
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Ive already looked at dong this .the idea was to turn the rear turbo around to face rearwards .however the bends would be too sharp for the twin dumps too work
Once you move the turbo you have to re-fabricate the turbo exhaust dump anyway .The idea of facing them both forward was considered however again you actually end up with more bends than the stock turbos with GOOD twin pipes
Since when does a GTR boost better than a 1j .MAYBE bog stock one is better than the other .But you only have to compare the two boosted EVEN without twin pipes a 1j's saving grace is big torque bottom end .The GTR is laggy and lacks anywhere near the torque of the 1j
i have a good mate with a boosted gtr with 3 inch exhaust intake mods apexi ecu etc .and apart from only being good for a 13.5 second 1/4 mile .Unless he dumps it 6000 rpm i walk away by two car lenghts every time
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Location:
Southern Sydney
Registered:
August 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Thu, 14 November 2002 22:28
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I agree. GTR's and skylines in general are overated.
1jz's make the same power as an RB26 using less boost. They are a more efficient engine for this very reason.
I'm going to leave it there....
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Location:
Preston
Registered:
June 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Thu, 14 November 2002 22:48
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1jz's make the same power as an RB26 using less boost. They are a more efficient engine for this very reason.
I'm going to leave it there....
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Not to mention the huge assed intercooler hanging out the front....
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Fri, 15 November 2002 00:13
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There is no doubt gains could be made with these mods, however i beleive, and I'm sure I'm not alone, there are more cost effective options for development of a 1j.
EVEN whilst keeping the standard ct12a turbo housings.
Matt
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Location:
newcastle
Registered:
June 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Fri, 15 November 2002 01:48
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heheeee and we are soon to find out how good danielson
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Location:
Gold Coast
Registered:
November 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Fri, 15 November 2002 10:21
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i have a good mate with a boosted gtr with 3 inch exhaust intake mods apexi ecu etc .and apart from only being good for a 13.5 second 1/4 mile .Unless he dumps it 6000 rpm i walk away by two car lenghts every time
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A Standard R32 GTR was qouted to do a flat 13 second pass also ive seen 13.2 qouted as well. With these mods ur mate should be able to better or even match these times at worst, maybe its his driving style that should be questioned.
I was thinking of a spacer block welded to the rear manifold one side flat the other machined to an angle.thus meaning that the intake for the rear will face towards the front right corner. Explain why there would be more bends ( you could have the intercooler pipes merged and u could have larger diameter pipes for intercooler also.)Not to mention twin intake pipes with twin air filters . Also twin dumps to the tranny.
I am a believer in the 1j, Torque is a big bonus and the gtr cooler gives it a plus .BOTH are strong motors from stock but stock the gtr has it down the quarter over a stock supra 2JZ.
For someone that can fabricate thier own pipes, i dont consider this to be an big dollar thing.
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Location:
newcastle
Registered:
June 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Fri, 15 November 2002 23:30
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i dont care if youve seen 10.8 quoted.they are also supposed to do SUB 5 sec 0-100 YET autospeed did a test and only 5.6 (at best) was achieved on a BIG launch .perhaps a quick trip to Eastern creek will tell a far sadder tale PLENTY of 14 sec times there for modified GTR's.
13.5 THATS WHAT HIS CAR RUNS .....CONSISTENTLY .the cressida runs consistant 13.0 but has run 12.8(once)
i blew a stock Supra 2jz silly about 3 months ago, why ?they are HEAVY .But i dont even begin to compare the two engines .with about $2,000 worth of mods the 2j engines will make close to 400 RWHP and run into the 11's
PLEASE dont start the 2jz debate and please dont embarrass yourself any further .a GTR is NOT EVEN 1/2 the engine of a 2jz
SURE the GTR'S have been modified to mega horsepower .but so has a holden rodeo engine
The Idea with dumps is to remove as much air and as much heat as quickly as possible . a simple exhaust backpressure test showed the twin pipes more than free flowing enough .In fact the exhaust system itself posed the greatest restriction
You obviuosly havnt even looked in the engine bay .the pipes still need to clear the steering rack so either way they end up coming through the same point .so when you alter the angle you add a bend
You did say turn the rear turbo so they both face front ward that would mean both exhaust outlets facing rear ward .The SHARPNESS and size of the pipe to do the back turbo bend would be more restrictive than twin pipes
how will angling the turbo be any different to twin pipes ?? i have twin 2.5 inch dumps 1/2 the way down the car .
Then you need to consider all sorts of things for your spacer block
what material ?? will it crack
do you bolt it or weld it to the exhaust manifold ??
WHY would you change only one turbo you will effectivley with the wedge shaped block change the runner length and the direction that exhaust gas hits the turbine wheel (unless you port the spacer VERY,VERY well.And if you can port that well then WHY are you even asking ) .
so now with one turbo responding and boosting differently to the
other your going to add (i bet) BIG intercooler plumbing .when sizing intercooler piping and even intercooler size you need to look at two things
1 the size of the compressor outlet
2. the temperature of the charge air to determine intercooler size
Although the 1js plumbing is ordinary the size and most effecient route of the plumbing is easily rectified in the standard position .surprisingly small plumbing will easily fix this
you have to remember your only dealing with enough airflow to make around 400 H.p .
The reason huge plumbing is used in mega h.p application is for FLOW and plently of it .BIG plumbing means more power BUT more lag .
In the case of the FACTORY turbo NOT MUCH MORE power is available they are usually already running outside their ideal efficiency ..lag on the street means u lose or do 150 KPH to win a race
So your setup WILL create a lag monster .thats provided the spacer doesnt leak or crack do you even know what material the factory exhaust manifold is made from ???
Having said all that your HALF way to a good idea .
the idea is to get two front turbos .extrude hone the factory manifold and make two manifold spacers(match ported) BUT locate them between the engine and the factory exhaust manifold .
Place a manifold insulator between the spacer and the exhaust .
This way the material used for the spacer is no big deal the insulator means different expansion rates are not a problem
The final entry angle for the turbos in uneffcted
Angle both turbos downward at the rear and your past the steering rack in two bends each pipe and not even 90 degree each bend .The big peformance advantage here is the manifold insulator reducing heat transfer and you get rid of one bend each pipe .
Having already gone tho this much trouble you might as well port the turbos for $800 why not!!!! end result youll max the injectors out at around 10-12 psi boost
even if you dont port the turbo the flow advantage from $200 worth of extrusion honing will give MORE power and LESS lag AND get MORE heat out past the turbo
The only catch is to take advantage of the new flow the exhaust MUST be VERY free flowing
ALTHOUGH as Yojimbo said
this setup is a poor mans excuse for a gt30 turbo and manifold and for the extra $1500 the gt turbo will last for 150,000 KLM (AT LEAST)
finally intake mods twin filters etc are great provided the filters FULLY encased and insulated from engine bay heat and have HUGE cold air ducting to them otherwise its a case of an INTERHEATER 
But wait about 4 weeks and i'll post dyno and performance time results from a 1j with ported turbos.Im using a mates car as a test bench (hes silly enough to trust me)
SORRY FOR THE WORLDS LONGEST POST BUT I THOUGH IT SIMPLER TO ANSWER THE WHOLE QUESTION
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Location:
Canberra
Registered:
May 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Sat, 16 November 2002 19:42
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Kudos to you Celicamad! 
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Location:
newcastle
Registered:
June 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Sun, 17 November 2002 10:56
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KUDOS?????
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Location:
Canberra
Registered:
May 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Mon, 18 November 2002 10:13
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ku·dos ( P ) n.
Acclaim or praise for exceptional achievement.
from dictionary dot com...hehe i didn't know it would be there but the meaning is what I was after!
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Location:
newcastle
Registered:
June 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Mon, 18 November 2002 11:27
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Thanx 
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Location:
Sydney Australia
Registered:
May 2002
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Re: 1JZ Turbo Position idea..Better than twin dumps??
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Mon, 18 November 2002 14:28
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my goodness... go play with ya kid!
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