Budget Turbo 250

[Anonymous]

i have been speakin to a few people about finishing off my turbo kit which i have started collecting parts for, it has cost me very little to collect the parts and it will be for mild street use.

i have a sharp Aussie XF 250 (4.1 inline 6) running straight impco LPG which i use as a daily driver. basically i want to turbo charge the car as a bit of a fun project and to learn all i can about turbocharging, basically this will be a project i can learn on with some R&D.

while the car is used daily i am not interested in 1/4mile times etc, all i am after is a car that is fast to road speed and pulls hard out of corners etc.... overall good street performance without breaking the law.

The kit i am building will be based around a T03 out of a R33 GTS-T (approx specs in a/r 0.50 and ex a/r 0.63) as these have the higher flowing exhaust housings. i know it is small but i would rather early boost and have it cut out earlier. i will be using 2.5 inch cooler piping with a largish front mount, striaght gas, ignition managements and a 3 inch down pipe to a 2.5 mandral system.

i was interested in peoples thoughs on what i will get out of the system, i was imagining a power band of up to 3500ish rpm (backpressure will then cause problems i think) and very rapid spool with lots of low down torque and maybe a peak power of something like 140 - 160 rwkw. what is your thoughts?

any recommendations are appreciated?

 

[Anonymous]

any thoughts on what my results may be or what problems i will come accross?

 

[XPC66]

Post the specs and numbers of the turbocharger. Then maybe we can workshop what to expect.

 

[Anonymous]

not alot of information is published about the nissan unit. it is a smallish T3 frame with an compressor ar of 0.50 and exh ar of 0.64. it has a 2 inch inlet and outlet in the compressor. it is internally wastegatted and has a ball bearing centre. i know the unit is fairly small, it will be used with a 450x300x76 cooler with 2.5 inch piping, a megasquirt computer and staight gas.

hope this helps

 

[XPC66]

I thought the RB25DET had different A/R to those you state. It was a roller bearing, ceramic turbine, T3 with A/R 0.40 compressor housing with 2 3/8"inlet/1 1/2"outlet.

Got any other info?

 

[Anonymous]

I thought the RB25DET had different A/R to those you state. It was a roller bearing, ceramic turbine, T3 with A/R 0.40 compressor housing with 2 3/8"inlet/1 1/2"outlet.

Got any other info?

not alot of info is published about them, i can tell you that they are a T3, ball bearing with a ceramic turbine wheel, i heard the ARs i gave are correct but who knows. they share the same size wheels as the RB20DET turbos but have a much higher flowing housing, to the point where the guys use them as a good upgrade on the 3.0Lt RB30s in the VLs which have a large T3 with a 0.82 ar but due to a better flowing housing the br25 oes are better.

basically i want very early spool, i am expecting the power to run out before red line but as its a daily thats fine as i ever hit redline usually as it is.

any info or recommendations would be appreciated

 

[Anonymous]

That turbo will be way too small. I would consider maybe using two of them.

The exhaust housing will choke the exhaust flow out of the engine. Go and have a look at the turbo on the BA twin cam engine. Ford had similar criteria to you, daily driver, fast spool etc and have come up with a much bigger unit than the one you are suggesting. They use a 1.06 A/R exhaust housing , 3" inlet (which is restrictive) and a 60mm compressor wheel inducer.

I wouldn't fit anything smaller than a BA falcon turbo. GT 35/40 is the ideal turbo for fast spool and good power on a ford six.

Unfortunately there is no cheap second hand turbos of anything Japanese that will be well suited unless you use two turbos.

 

[Anonymous]

yea the BA turbo would be nice but they go for $1000 second hand and i have very cheap access to a good condition R33 turbo for a good price. i already have a manifold and down pipe for it as part of my kit and was really looking for nice low down power as im not too worried abot top end for a daily driven car. when does everyoe reckon the turbo will choke up? 3000ish? considering it only revs to 4500 and i never take it that far anyway (usually) that would be fine

 

[XPC66]

The best you're going to get from anyone is a punt, inless you can furnish more information, e.g wheel sizes and trims

 

[Anonymous]

ok i managed to find out a little more information. the trims are not published as with the graphs but i can tell you this.

T3 Frame
Higher Flowing Housings
45mm compressor intake wheel
45mm compressor outlet
44mm turbine wheel exit

apparently these are fairly efficient and high flowing (can also be high flowed later on)

thought on what i could expect?

Cheer Guys

 

[rbohm]

8) for what you want, the turbo you have will be fine, since you dont plan on turning more than 5000 or so rpm. if you are running a blow through set up, i would highly recommend a blow off valve, along with a wastegate, to prevent overboosting. if you are running a draw through system, use a pto wastegate, and set the boost limit about 2 psi below where you want it, since with the small size of the turbo you will have near instant boost, so be prepared for that. i would also get a good quality exhaust manifold and have it extrude honed to maximum flow, and i would also have the manifold coated to prevent cracking under high heat that it will encounter using the turbo. also have the manifold you get stress relieved as that will also help prevent cracking.