Hi all,
I know. Another turbo thread. Before you exit, I wanted to create this as a reference for others looking for this information in one spot. I've spent hours going through the forum, finding answers to some, but not all, of my many questions.
Now I'm no turbo expert, so id like to answer a few common questions plus, id also likes to ask a few more.
For starters. As a baseline, I'm running a 1988 GQ TD42 N/A silver top in the shorty. It's a pig. I'm yet to have her pump tuned as a N/A, but I am looking at having it put off for the purpose of doing a turbo to tune it after the kit is on.
So firstly, questions I know answers to.
Q1. What turbo kit is the best?
A1. There is no perfect kit. There are kits available off the shelf but with so many different vehicles with so many different variables between them. Also, factoring that no two people ever drive the same, nor do they want the car to perform the same, no turbo kit will ever be perfect. But there are some good brands that come close, such as DTS by MTQ, Safari (same as the snorkel brand) and a few others.
Q2. What's the max boost I can run on a silver or blacktop?
A2. Silver tops are stronger in general than black tops. Heavier internals means they can handle more boost. Silver tops can handle in excess of 20psi, and I've heard of people (not proven to me yet) running up to 50psi. But by this stage, the head begins to lift. Black tops are a random jack in the box. I've heard of black tops calling it quits at 5psi and others handling 15psi all day. The general rule, as I can read it, however, is black tops should see no more than 12 to 14 psi.
Q3. What's the biggest boost you can run into a TD42 without an intercooler?
A3. Once again, you will hear a varied number. Mostly its considered 12psi is the limit for non-inter-cooled turbo setups. This is mainly for the engine's longevity and to keep the exhaust temperature down.
Q4. What do you need when upgrading?
A4. The list starts at the turbo, turbo manifold, oil supply lines (depending on the turbo, you could require coolant lines) and a dump pipe to attach an exhaust system.
Q5. Do you have to upgrade your injector pump?
A5. The short answer to this is no. You don't HAVE to. But it's recommended. This is because a non-turbo engine has a non-turbo pump. The difference between them is called a boost compensator. A boost compensator adjusts the fuel-to-air mixture as the turbo spools and provides pressure. So, therefore, more boost = more fuel. Less boost = less fuel. Think of it like your best mate is under the bonnet with a boost gauge and a screwdriver on the fuel screw. You don't have to have a fuel compensated pump. However, if you choose not to, the pump will need to be tuned to provide the fuel it needs at its highest level of boost. So this means if your turbo is set for 15psi and the pump is tuned for 15psi worth of fuel, at 2psi, it still provides 15psi worth of fuel. This causes a major fueling off-peak boost (provided your pump's plunger can provide that amount of fuel).
The other side to this is plunger size. A factory GQ pump (turbo or n/a) is 10mm. There are rumours of late GQ, but definitely, GU factory turbo pumps are 11mm, which can provide enough fuel for up to 20 psi. Any more than this, and you will need a 12mm pump. Bigger than 12mm is very uncommon unless you're chasing huge power.
Q6. How much power can you make from a turbo TD42?
A6. This all comes down to turbo pressure, fuel flow, pump size and condition, engine condition, tyres and rims, as well as exhaust and intake modifications. A lot of factors contribute to the power your engine can produce. So no one can tell you an exact figure. But you can always get a ballpark figure from others dyno sheets from vehicles with similar setups.
Q7. Low mount or high mount turbo?
A7. There is no correct or perfect setup here. A low mount is more concealed and therefore hidden. However, low mount manifolds are costly, and the plumbing is harder. It's also harder to do repairs or maintenance to the turbo. Low mounts also mean they are closer to the ground. Water crossings will mean the turbo hits the water more often on deep crossings. High mounts are easier to set up, plumb and work on. But there are rumours of high mounts heating the firewall easier as well as making it harder to fit a top mount intercooler, depending on your setup. There's a lot to consider here, so a google image search of both gives you some good images to froth over.
Q8. Best exhaust and intake mods
A8. Exhaust, 2.5" or 3" mandrel bent is the go. Stainless lasts longer, but mild steel is cheaper. The different materials also offer different sounds and notes. Intake mods are simple. Throw out the stock airbox, IMO. Its rubbish and square fittings are hard to waterproof. A ZD30 airbox is a common upgrade, and there are even stainless copies of them available from Patrolapart, which work a treat. There are other airbox designs, too; however, some eliminate the option of a secondary battery, and others require a certain snorkel style. Best to do some digging first
Q9. What turbo brand/model is best?
A9. Once again, there are no one size fits. Everyone has their favourite. I personally like the TD05-18G, and others like the GTX2860/2860RS. Two very common turbos, there are a few other brands and models out there, but these seem to be the top two. Depending on where you get it from, many turbo shops can build a turbo for you from a stock form to suit your engine and requirements. They can adjust sizing and flow to make turbos spool at different times and even high flow them for more pressure. Just have a chat with them first about your needs, and they can suggest the right setup for you.
Q10. What's the best way to tune a TD42 after it's been turbo'ed?
A10. You don't. Take it to someone who knows what they are doing at $3k or more for a pump and possibly even more for a rebuild, and you don't want to be messing with your engine setup. Diesel is the particular motor and runs within a tight tolerance. Don't risk it! Unless you're a pro, take it to one!
I know. Another turbo thread. Before you exit, I wanted to create this as a reference for others looking for this information in one spot. I've spent hours going through the forum, finding answers to some, but not all, of my many questions.
Now I'm no turbo expert, so id like to answer a few common questions plus, id also likes to ask a few more.
For starters. As a baseline, I'm running a 1988 GQ TD42 N/A silver top in the shorty. It's a pig. I'm yet to have her pump tuned as a N/A, but I am looking at having it put off for the purpose of doing a turbo to tune it after the kit is on.
So firstly, questions I know answers to.
Q1. What turbo kit is the best?
A1. There is no perfect kit. There are kits available off the shelf but with so many different vehicles with so many different variables between them. Also, factoring that no two people ever drive the same, nor do they want the car to perform the same, no turbo kit will ever be perfect. But there are some good brands that come close, such as DTS by MTQ, Safari (same as the snorkel brand) and a few others.
Q2. What's the max boost I can run on a silver or blacktop?
A2. Silver tops are stronger in general than black tops. Heavier internals means they can handle more boost. Silver tops can handle in excess of 20psi, and I've heard of people (not proven to me yet) running up to 50psi. But by this stage, the head begins to lift. Black tops are a random jack in the box. I've heard of black tops calling it quits at 5psi and others handling 15psi all day. The general rule, as I can read it, however, is black tops should see no more than 12 to 14 psi.
Q3. What's the biggest boost you can run into a TD42 without an intercooler?
A3. Once again, you will hear a varied number. Mostly its considered 12psi is the limit for non-inter-cooled turbo setups. This is mainly for the engine's longevity and to keep the exhaust temperature down.
Q4. What do you need when upgrading?
A4. The list starts at the turbo, turbo manifold, oil supply lines (depending on the turbo, you could require coolant lines) and a dump pipe to attach an exhaust system.
Q5. Do you have to upgrade your injector pump?
A5. The short answer to this is no. You don't HAVE to. But it's recommended. This is because a non-turbo engine has a non-turbo pump. The difference between them is called a boost compensator. A boost compensator adjusts the fuel-to-air mixture as the turbo spools and provides pressure. So, therefore, more boost = more fuel. Less boost = less fuel. Think of it like your best mate is under the bonnet with a boost gauge and a screwdriver on the fuel screw. You don't have to have a fuel compensated pump. However, if you choose not to, the pump will need to be tuned to provide the fuel it needs at its highest level of boost. So this means if your turbo is set for 15psi and the pump is tuned for 15psi worth of fuel, at 2psi, it still provides 15psi worth of fuel. This causes a major fueling off-peak boost (provided your pump's plunger can provide that amount of fuel).
The other side to this is plunger size. A factory GQ pump (turbo or n/a) is 10mm. There are rumours of late GQ, but definitely, GU factory turbo pumps are 11mm, which can provide enough fuel for up to 20 psi. Any more than this, and you will need a 12mm pump. Bigger than 12mm is very uncommon unless you're chasing huge power.
Q6. How much power can you make from a turbo TD42?
A6. This all comes down to turbo pressure, fuel flow, pump size and condition, engine condition, tyres and rims, as well as exhaust and intake modifications. A lot of factors contribute to the power your engine can produce. So no one can tell you an exact figure. But you can always get a ballpark figure from others dyno sheets from vehicles with similar setups.
Q7. Low mount or high mount turbo?
A7. There is no correct or perfect setup here. A low mount is more concealed and therefore hidden. However, low mount manifolds are costly, and the plumbing is harder. It's also harder to do repairs or maintenance to the turbo. Low mounts also mean they are closer to the ground. Water crossings will mean the turbo hits the water more often on deep crossings. High mounts are easier to set up, plumb and work on. But there are rumours of high mounts heating the firewall easier as well as making it harder to fit a top mount intercooler, depending on your setup. There's a lot to consider here, so a google image search of both gives you some good images to froth over.
Q8. Best exhaust and intake mods
A8. Exhaust, 2.5" or 3" mandrel bent is the go. Stainless lasts longer, but mild steel is cheaper. The different materials also offer different sounds and notes. Intake mods are simple. Throw out the stock airbox, IMO. Its rubbish and square fittings are hard to waterproof. A ZD30 airbox is a common upgrade, and there are even stainless copies of them available from Patrolapart, which work a treat. There are other airbox designs, too; however, some eliminate the option of a secondary battery, and others require a certain snorkel style. Best to do some digging first
Q9. What turbo brand/model is best?
A9. Once again, there are no one size fits. Everyone has their favourite. I personally like the TD05-18G, and others like the GTX2860/2860RS. Two very common turbos, there are a few other brands and models out there, but these seem to be the top two. Depending on where you get it from, many turbo shops can build a turbo for you from a stock form to suit your engine and requirements. They can adjust sizing and flow to make turbos spool at different times and even high flow them for more pressure. Just have a chat with them first about your needs, and they can suggest the right setup for you.
Q10. What's the best way to tune a TD42 after it's been turbo'ed?
A10. You don't. Take it to someone who knows what they are doing at $3k or more for a pump and possibly even more for a rebuild, and you don't want to be messing with your engine setup. Diesel is the particular motor and runs within a tight tolerance. Don't risk it! Unless you're a pro, take it to one!
🍻
