fabbing 1uz turbo manifold questions

[stevechumo]

Stock t25 turbos off of the 2.0L eclipse would be the best oem swap to a 4.0L UZ with regard to spool/choke. Instant spool with around 300-325whp easily on stock fuel/tune. Each one will flow 210bhp-230bhp each. A pair of CT20's would be the better pair if your looking for more hp.

I agree. A pair of T25 will be good enough for more than 400 hp. Some Mitsu guys even made to 250 hp on their Eclipse. The rule of thump in a turbo setup isn't to have an overkill turbo. Big turbo will give lagging accelleration, which is very boring to drive on the streets. Even a slightly bigger turbo can be quite boring as well.

 

[XR8tt]

Some confuse lag with difference between n/a power and power when engine spools and comes on boost.. The higher the boost / cfm the greater the difference...
Even though rpm is about the same...
You can go bigger turbo on an engine twice the size as you don't need 400+ h.p instantly!! On a 2ltr yes 200 would be nice...
Keep mind with std assembly the compression is quite high.. There won't be too much
transition from cruise to WOT.. Most factory turbo engines are around or under 9 to 1 compression..

 

[spf_lexus]

Most factory turbo engines are around or under 9 to 1 compression..

Its also been discussed wether or not the early uz was 9:1 instead of the listed 10:1. But even still, if the goal is simplicity, stock fuel/tune will cap you off at 7-8psi which would be as high as you would want to go with even at 10:1 cr. I dont know the mitu stock boost but at 7psi, its pretty safe overall. Its when 400bhp is not enough that you consider something larger, because at that stage your really boosting the budget as well.

 

[AutoLuxLexES]

Stock t25 turbos off of the 2.0L eclipse would be the best oem swap to a 4.0L UZ with regard to spool/choke. Instant spool with around 300-325whp easily on stock fuel/tune. Each one will flow 210bhp-230bhp each. A pair of CT20's would be the better pair if your looking for more hp.

That's why I went with Garrett t25 from sr20det motors. I finally have my 2 units and getting my ss304 exhaust flanges from the waterjetter in a couple days. Making some progress so far. Little by little.
Charley

 

[em_knaps]

LPT (low pressure turbo) systems are very popular in europe, Saab, PSA Volvo etc..

Generally the engine retains a high compression ratio that a similar NA engine
would have,

the turbo's are small, and the boost is low ~5psi.

this beafs up and flattens the torque curve which is available from around 1500rpm.

My supra runs the factory compression ratio of 10:1 and I run large T3/T4 turbo's which
are on song at around 3500rpm with 7.5psi.

it is somewhat annoying but I built the system with engine mods in mind,
namely decompressing the engine and adding more boost, which the 10:1 compression would not tolerate.

My intention is to twin turbo a 1UZ with small T25's or sim so that boost response is immediate as it will be going into a landcruiser.

Lag is ok in the supra, its has a 4L v8 with enough power off boost, and a close ratio gearbox that keeps the engine above the magical 3500rpm when I'm thrashing the pants off it.

But in a 4x4 you dont want to be waiting for turbo's to spool.

In a factory Silvia with a SR20DET the small turbo boosts quickly, you have pressure around 2000rpm but you are limited to ~250hp with the small turbo. to much boost over-speeds the turbo and also goes beyond its most efficient operating range.

The result of this is heat. everywhere. and most likely a broken turbo will also result or engine, if your tune is average or det becomes uncontrollable due to the extra heat in the intake air.

Put tiny turbo's on your engine, but be prepared to have the engine choked at high rpm.
Put oversized turbos on your engine, but be prepared to wait for the boost/power.

research folks, corky bells book maximum boost is a good read.
a fluff around on:

http://www.turboneticsinc.com/choose_turbocharger
http://www.turbobygarrett.com/turbobygarrett/
http://www.turbofast.com.au/
http://www.bankspower.com/

I must warn against reading forums to find out important details, manufacturer's publications are really the best place to find info, as they are require to provide accurate info to their customers.

I can write anything i like on a forum, but who is going to hold me to account if the information i provide is erroneous?? nobody.

Ok, thats enough ramblings from me for today.

 

[stevechumo]

A real life example is that I drove a turbo 1UZ with a T70 turbo on it. It's laggy to the point that I could feel I could light up a cigarrett and wait for the boost to kick in and the car starts moving quicker. However, on my car, a T60-1 turbo which is smaller than a T70 gave me boost and quick accelleration almost instantly.

 

[Alan Whitaker]

Hi All

You were right re the stock turbos, I called the guy and the ones I got were ftom a RB25 and he had the pr on his engine, He said the pr should be ok on 4.0l engine, I hopy so,

Alan

 

[em_knaps]

2 RB25 turbo's id say would be perfect, from memory they are ceramic, which means they are light and will spool fast. but dont tolerate high boost or heat abuse,

be sure to plumb the water cooling to those turbo's. do some research on this as when you switch the engine off the cooling needs to be able to thermo-siphon.

there is some info on this in the garret lick from my previous post...

I guess I am getting off topic, this thread is about fabbing manifolds.

Although everything needs to be considered when placing a turbo, such as oil drain angle, shaft angle, accessibility to water in/out, possible external wastegate integration... all of which influence turbo manifold design.

 

[Alan Whitaker]

Hi,
The turbos have a steel wheel conversion, he said the ceramic blades were replaced and the steel ones are better,
Water is one thing I need to look at I was hoping to use the water lines from the oil filter but not sure which one is in and which one is out.

Alan

 

[em_knaps]

for those who like compressor maps:

http://www.not2fast.com/turbo/maps/

for those who don't know what one is or cant read one i suggest more research on how to read them is in order... they are quite important should you want a perfect matched engine/turbo combination.

 

[XR8tt]

It's really not wise to consider turbo size by its power ..
Should be looking at turbine / compressor maps in CFM...

Could have troubles with high exhaust back pressure...

A T70 is slow to respond on a 5.0 litr..
The T64 would be about right with correct trim and A.R..
Shaft bearing and oil cooled housings..

A T04Z [66mm] with .84A.R turbine housing however, has almost instant boost..
Has nice long power curve also without peaking too early...Smoking tyres...

Much easier than fitting twins ...

Things to consider when making a manifold..

 

[kildea]

I used SCH10 304... it was easy to work with and cheap.

I stumbled upon this post over the weekend and I was curious why you chose to pair the ports as you did?

 

[RedPhoenix]

I stumbled upon this post over the weekend and I was curious why you chose to pair the ports as you did?

space issues... i would do 1/3 and 2/4 if i had the room.

 

[XR8tt]

It won't make much difference at the power levels here..
The restriction is still in the turbine...
Stop thinking N/A manifolds...

 

[ash]

It's really not wise to consider turbo size by its power ..
Should be looking at turbine / compressor maps in CFM...

..

you mean Lb's /min

 

[XR8tt]

you mean Lb's /min

YEP !!

Welds look like the amps could be turned up or lower wire speed ??

 

[Hachibill]

2 ct26's will work fine. Just get the one's off a 3sgte.

 

[Apollyon44]

I can let it go for a price that won't cost you an arm and a leg. Guaranteed. The longest and hardest part is the turbo manifolds. If you want your car up and boosting quickly, then shoot me a PM. heh..heh.

I’m new to the forum and I’m not quite sure how to PM but I’m very interested in your setup or atleast the turbo manifolds. Could you pm me please? Thank you in advance.

 

[stevechumo]

I’m new to the forum and I’m not quite sure how to PM but I’m very interested in your setup or atleast the turbo manifolds. Could you pm me please? Thank you in advance.

I haven't been back here for a long time. My comment was 10 yrs ago. Lol.