tuning the gt turbo

[jonnyshaw49]

hi havnt been on here for a while, my friend has just bought a gt turbo and asked me to help him sort it out and tidy it up. my car is nearly ready for the road after a long 2 year restoration and over 6k spent. could anyone tell me or post me in the right direction for any thread on tuning the gt turbo upto 15 psi on standard turbo. i have already told my friend what to buy to get it set up, all the basics, low temp fan switch new dizzy , dizzy rotor arm and leads ,full service kit, carb overhaul kit, green seals, new king lead,new mixture screw, double alloy intercooler, boost,oil pressure and rev guage, oil cooler.all the things needed to keeps things in check! my car is running 200 hp and i have a wideband set up. but because i havnt touched my car for over a year im a little rusty on jet sizes for tuning. could anyone tell me what jet sizes are needed to wind standard turbo upto 15 psi? the car is going to be put straight on the rolling road to check afrs after ive done it but just need to make sure i have correct jet sizes in the carb! appreciate any help thanks

[markey mark (bd)]

hi havnt been on here for a while, my friend has just bought a gt turbo and asked me to help him sort it out and tidy it up. my car is nearly ready for the road after a long 2 year restoration and over 6k spent. could anyone tell me or post me in the right direction for any thread on tuning the gt turbo upto 15 psi on standard turbo. i have already told my friend what to buy to get it set up, all the basics, low temp fan switch new dizzy , dizzy rotor arm and leads ,full service kit, carb overhaul kit, green seals, new king lead,new mixture screw, double alloy intercooler, boost,oil pressure and rev guage, oil cooler.all the things needed to keeps things in check! my car is running 200 hp and i have a wideband set up. but because i havnt touched my car for over a year im a little rusty on jet sizes for tuning. could anyone tell me what jet sizes are needed to wind standard turbo upto 15 psi? the car is going to be put straight on the rolling road to check afrs after ive done it but just need to make sure i have correct jet sizes in the carb! appreciate any help thanks

Alright mate, for 15psi on standard engine and T2 you won't need half that stuff.

A good service would be in order for sure, standard fan switch and thermostat are fine as is the standard oil cooler if rad is in good condition.

As for your car mate whats the engine spec, is it standard?
Standard size or double capacity intercooler will be fine

[jonnyshaw49]

hi mate he wants to make sure everything is good and kept an eye on for getting more power out of it! in the future he wants more power but just wants to do the little mods now to get the most out of it. the engine is totally standard so was going to wind the boost up to 15 psi just on the actuator rod and do away with the adjustable boost controller! would he need something like a 140 jet and a 0.90 air corrector or am i miles out? can you think of anything else that would give abit more power? hes getting the turbo elbow bored out and has a full stainless exhaust already. appreciate the help!

[markey mark (bd)]

hi mate he wants to make sure everything is good and kept an eye on for getting more power out of it! in the future he wants more power but just wants to do the little mods now to get the most out of it. the engine is totally standard so was going to wind the boost up to 15 psi just on the actuator rod and do away with the adjustable boost controller! would he need something like a 140 jet and a 0.90 air corrector or am i miles out? can you think of anything else that would give abit more power? hes getting the turbo elbow bored out and has a full stainless exhaust already. appreciate the help!

For 15psi on the standard T2 and engine he'll prob need to drill 2nd stage to 1.1mm and maybe a 1.1mm ac but thats about it.

Even if he wants more power standard cooling and cooler should be up to job, proved itself more than a few occasions :wink:

On the T2 the bored elbow doesn't do too much, saying that doesn't do much on bigger turbo either he's best keeping eye out for a one piece downpipe and elbow

[jonnyshaw49]

hi so if i drill the second stage and buy a 1.1 air corrector thats enough? does main jet not need changing? is there a main jet worth buying if it needs a bigger jet once its put on the rollers with afr up exhaust? where can i get a 1.1 air corrector as ive only seen 0.9 fron ktec. appreciate the help thanks

[markey mark (bd)]

hi so if i drill the second stage and buy a 1.1 air corrector thats enough? does main jet not need changing? is there a main jet worth buying if it needs a bigger jet once its put on the rollers with afr up exhaust? where can i get a 1.1 air corrector as ive only seen 0.9 fron ktec. appreciate the help thanks

You won't need a larger main jet, even on my old 230bhp engine i had a 1.2mm standard main jet.
Its only rough guide mate, to know exactly what the carb will need you have to use an AFR gauge on the car while driving or on a rolling road but its a start it should put you in the right area.
You'll either have to redrill the ac mate or souce one from Mike@GTTurbo spares, sure he's got a few ac jets in various sizes. The 2nd is fixed so will need drilling

[jonnyshaw49]

hi thanks alot for the reply, i have the aem wideband but its welded into my exhaust so cant use it on his car. ive had a mess with the carb today got it running 100 percent better cleaned all jets set mixture and idle. the engine sounds alot smoother.ive replaced all the vaccum hoses and checked for leaks. only place i could kind of find a leak was on the forge dumpvalve when spraying carb cleaner on it hunts abit but think this is because its not pulled shut on idle. the diaphragm seems good, wonder if the spring could be too strong holding it open. its the green spring. only problem were having now is when the lad stalls the car it wont start for ages. loads of easy start is needed. we was stuck on a hill aswell though could this be the floats in the carb not level? we are going to rebuild the carb next weekend so will give it a good look over and sort drilling second stage and get a bigger acc jet. then it will be going on the rolling road so will try and see what it needs but sure old man at mini sport will sort it!