Turbo 4AFE mod

[Psycho_rolla]

Ok heres the thing I want to put a t-25 turbo off a nissan ET pulsar on to the 4AFE.

My questions are:

1) Will i need to do any engin mods first ?? If so what??
2) Will the gearbox handel it or will i need to upgrade it??


Thanx in advance
Ben

[Psycho_rolla]

Oh and i must add That its pre EFi and still running the stock carby

[Flashmn]

1) not really if you're not gonna run high boost. Enclose the carb in a box and lead the charge pipe there. (the easy way)
2) Yeah it will handle it, but dont expect the clutch to survive long.

[Psycho_rolla]

well im planning on running stock boost from the t-25 for now till finances allow me to engine mods :soyeah:

[Flashmn]

Stock boost? theres no such thing as "stock boost" on a turbocharger, the turbo will blow as much pressure as the wastegate is set to. I guarantee a T-25 with full boost (wastegate shut) will blow your 4A-F to shit (not to mention the turbo itself)

[Psycho_rolla]

yeah i know that jez but a stock t-25 with a stock waste gate will boost to about 7 -8 psi (thats the Nissan ET pulsar)

[gasman]

hey flashmn how your turbo 4af coming along?

[Flashmn]

Slowly, I'm still doing the head, I need to get new valveseats, as the stock ones are 1mm too small in diameter for camry valves that I'm installing (from a 3SFE).
Also I should be getting my new intake manifold and throttlebody this week, I'll also be getting Dual injectors from a ST175 Celica and a Camry. Gonna run Megasquirt with dualtable that way I can bet better fuel economy and More precise fuel delivery, compared to carbs which is the equivalent of flushing the toilet, except with gas.
Otherwise its going fine. Should start my exhaust manifold ver 2.0 soon too. Its gonna be nothing like you've ever seen before

[PPW-546]

easiest way is the blow-thru turbo system meaning the charged air goes straight to your carb using a pipe adaptor.

if you want your engine to have a longer life, might as well swap to low comp pistons since turbocharged engines run on low comp to avoid blowing the engine up.

you might want to use a smaller turbo that matches the engine such as the CT9 or CT12 that comes straight off a toyota engine.

[Psycho_rolla]

Originally Posted by PPW-546

easiest way is the blow-thru turbo system meaning the charged air goes straight to your carb using a pipe adaptor.

if you want your engine to have a longer life, might as well swap to low comp pistons since turbocharged engines run on low comp to avoid blowing the engine up.

you might want to use a smaller turbo that matches the engine such as the CT9 or CT12 that comes straight off a toyota engine.

Ahh okiez where they on the aussie cars at all cuz the t-25 was on the nissan's and are readly avaible in oz.

can the stock carbs be pressurized or will i need a holly, cuz if i need a holly i was thinking a 180cfm

[Flashmn]

Yes they can, and like I said the easiest way to pressurize it is by encasing the carb inside a box with the chargepipe connected to it. Its dead easy.

[punter]

Yes Flashmn is right thats the easiest way, The only comment I would make is watch your fuel pressure.
Guys over here can't run over 6psi on blow through carb setups (4k motors) because it can't pump anyfuel into the carb.

[Flashmn]

Plan to use an EFI pump, Fuel pressure regulator as you need to run boost pressure + needle valve pressure. Which in atleast webers is 0.10-0.30bar, dunno about the stock carb.
I gave away on carb turbo, its a pain in the ass to tune.
Time to step into the new era and I'm going full programmable EFI.

[Psycho_rolla]

Ahh sweet wasn't sure if it could be pressurized or not

[Flashmn]

In general all carbs can be pressurized, its just that the thottle axle will leak, the floats might crumple and the vacuum stuff wont ofcourse work that well.

CT9 and CT12 are dieselturbos right? Word of caution, you do not want to use a small diesel turbo on a gasoline engine. The turbine housing is so small and restrictive, it will raise exhaust side temps alot. Eventually you'll overheat the exhaust side and cause either valve seat dislocation or valve guide droppage. Ofcourse if you use a big holset from a 6 liter truck you wont have a problem, but for example a 1C-T is a 1.8liter engine.
Also, a small turbocharger will always have problems in the upper end of the RPM band.
I personally would rather have a big turbo than a small one, low rpm lag isnt as annoying as lack of power at high rpm.