jets for t25

[KEV 5 GT]

can anyone tell me what jets to start off with to fuel a t25 im starting with a stock carb but have a few jet sizes to hand

[BluntyR5GTT]

First of all have you got an afr kit?
Secondly what boost will you be running?

[BluntyR5GTT]

If your on standard venturi carb then stick with standard main jet no need to change that. The main areas you need to look at are second stage and air corrector.

[Jonny5]

All in here!

http://www.rtoc.org/boards/showthread.php?t=460

[KEV 5 GT]

yes ive got afr kit and want to run as much boost through it as poss ??
ive got 2 carbs one stock the other drilled 2nd stage about 1.3

[BluntyR5GTT]

well id personally go for the carb with the drilled 2nd stage, keep oe main then drop the ac down to 100, see how it goes then if you require a bit more fuel try a 0.9 ac

[Markey Mark (BD)]

What spec is your T25 too as you may be limited with the amount of boost you can run which will determine the size of jets you use on the carb

I'd personally start with the completely standard carb so you got a good starting base as you my find 1.3 2nd stage too big

As a basis leave standard main as mentioned by Andy, the 2nd stage fuels boost so concentrate there. I only really touch the ac jet if it slightly leans out top end, sometimes you don't really need to reduce this too much if the 2nd stage is big enough. If you do 1mm is about as small as you want to go (smallest I ever used)

Also check your fuel system is good too, no point jetting carb if fuel pump is on its way out

[KEV 5 GT]

I believe the turbo to be a full t25 from rover m42/48 what can these take full blow ?

[Markey Mark (BD)]

I believe the turbo to be a full t25 from rover m42/48 what can these take full blow ?

If it is a Rover tomcat T25 with standard thrust bearings then not a lot, if its been tweeked with 360 bearings and housings changed abit (some normally do) then they could take abit, I set one up to around 22psi on a car but did have the turbo built with all the bits fitted into it to cope with the bigger boost pressure

[KEV 5 GT]

how can you tell if its been tweked abit and if not what boost you recommend

[Markey Mark (BD)]

how can you tell if its been tweked abit and if not what boost you recommend

Do you know of where the turbo come from or any specs of it?

[KEV 5 GT]

I had it off gary on here I think it says m27/48 on housing

[BluntyR5GTT]

If it is a Rover tomcat T25 with standard thrust bearings then not a lot, if its been tweeked with 360 bearings and housings changed abit (some normally do) then they could take abit, I set one up to around 22psi on a car but did have the turbo built with all the bits fitted into it to cope with the bigger boost pressure

as above here you don want run anymore han 14psi on a tomcat t25 unless its had the upgrades carried out, also what actuator do you intend to run ? ideally you want a -31 or -34.

have a look on your turbo exhaust housing there should be markings on it somewhere to tell you what size it is, if is a tomcat it should say .49 just a note my marking is on the inside of the outlet

[KEV 5 GT]

ive got a Collins 31 it says on the comp housings m27 a/r 48

[Markey Mark (BD)]

Looks like a standard Tomcat turbo to me, housings are still original and not been rotated
I normally had the front housing changed for a different one to remove the standard built in dump valve

The sizes will be stamped A/R then a number, for example A/R 49 or you will just see .49 stamped somewhere.

[KEV 5 GT]

ive got a blanking plate to fit in place of the dump valve would you say no more than 14psi then ? what bhp would I expect from that ?

[Markey Mark (BD)]

ive got a blanking plate to fit in place of the dump valve would you say no more than 14psi then ? what bhp would I expect from that ?

If its standard then yes wouldn't go more than 15psi

BHP will all depend on what spec your engine is and how well its set up too