Turbocharging a 4.6 V8
#1
Turbocharging a 4.6 V8
So, I've been chewing on this idea for quite some time. I've done about all the research I can on my own and now I'm looking for some actual help.
I want to turbo my 4.6. Right now it has a Kent H180 cam, Rhoads lifters, Port and polish, intake, and exhaust. It runs like a top and I love driving it. Until I have to tow anything. Then, even with light loads (less than 3k lbs), it becomes the most sluggish thing you've ever seen, barely climbing the smallest of inclines without shifting to second and turning half a million RPMs. This wouldn't be a problem, but I pull quite a lot and I live in the Appalachian and it's far from flat here.
Here is my plan as of right now and I'd like feedback. I don't want much boost, just enough to give it a little kick. I'm thinking 3-5 lbs. Maybe run it at 3 and kick it up to 5 when I am pulling, supplied by either a Garrett t3 or t4 turbo. That would be coupled behind a set of P38 shorty headers (will these fit a Disco?), 2.5" pipe all the way, no cats, and back to my Borla muffler, and then dumped out in front of either side in front of the wheels. Intake piping would run from a custom snorkel, down to the turbo, to an intercooler, then up to the MAF and into the throttle body. Id like to leave all the stock electronics for simplicity sake and maybe throw in some 24 lb injectors. Then go to an electric water pump to get more consistent and higher flow speed, a full size chevy truck radiator, and dual high flow electric fans with an in line thermostat mod to keep everything running nice and cool.
Thanks for any feedback you all have.
I want to turbo my 4.6. Right now it has a Kent H180 cam, Rhoads lifters, Port and polish, intake, and exhaust. It runs like a top and I love driving it. Until I have to tow anything. Then, even with light loads (less than 3k lbs), it becomes the most sluggish thing you've ever seen, barely climbing the smallest of inclines without shifting to second and turning half a million RPMs. This wouldn't be a problem, but I pull quite a lot and I live in the Appalachian and it's far from flat here.
Here is my plan as of right now and I'd like feedback. I don't want much boost, just enough to give it a little kick. I'm thinking 3-5 lbs. Maybe run it at 3 and kick it up to 5 when I am pulling, supplied by either a Garrett t3 or t4 turbo. That would be coupled behind a set of P38 shorty headers (will these fit a Disco?), 2.5" pipe all the way, no cats, and back to my Borla muffler, and then dumped out in front of either side in front of the wheels. Intake piping would run from a custom snorkel, down to the turbo, to an intercooler, then up to the MAF and into the throttle body. Id like to leave all the stock electronics for simplicity sake and maybe throw in some 24 lb injectors. Then go to an electric water pump to get more consistent and higher flow speed, a full size chevy truck radiator, and dual high flow electric fans with an in line thermostat mod to keep everything running nice and cool.
Thanks for any feedback you all have.
Last edited by Alex_M; 07-13-2015 at 06:44 AM.
#3
Thanks Mike, that's what I was looking for. I was hoping the stock ECU would be fine for just 3-5 lbs, and I'm in the process of lining up parts for a T5 manual swap, but if the ECU won't work then I'll just drop the idea and save for gears/transmission.
#4
V8 tuners and RPI do ECU performance programming. I don't know if they would be able to tweak it for your Turbo set up, but it doesn't hurt to reach out to them.
As far as the trans not being to handle the extra "ummph ", Mike has a good point. I wonder if it's any different than these guys that get 5.0 performance motors from cannibal and such?
As far as the trans not being to handle the extra "ummph ", Mike has a good point. I wonder if it's any different than these guys that get 5.0 performance motors from cannibal and such?
#5
#6
I wouldn't be so quick to dismiss the ECU without first determining the max flow rate of the stock MAF and stock injectors.
If the stock MAF is being pegged by a stock 4.6L, or even a cammed 4.6L, then it's useless in a forced induction application. If not, you might be able to use it for a few PSI.
I don't know of any aftermarket MAF for the Rover V8 application, but my exposure to the engine has only been via Land Rover. I'd wager that if you reached out to some of the Rover discussion groups in the UK, they might have some meaningful insight for you if the stock MAF is a workable solution, or if you're going to need an aftermarket part.
Next obstacle is fueling. Same deal, if your stock injectors are running at peak output with minimal N/A modifications, then they're not going to hold up in a forced induction application. You'll run lean and ultimately start melting important things like valves and pistons. I don't know the flow rates on the stock injectors, but again, answering that and how close they are to max duty cycle right now will determine if they're suitable to use with the light forced induction you plan on doing. Same deal with the MAF, reach out to the Rover community for guidance here, as some of them have dealt with these questions.
If there's enough reserve capacity with the MAF, and with the injectors, then you'd probably be able to get away with a low pressure turbo setup on the stock ECU. It's been done on plenty of applications over the years, and the fact that the Rover V8 used in the DII is MAF based rather than speed density (MAP based), you have a higher likelihood of success.
On engine and transaxle cooling, you're going to want an engine oil cooler, a bigger transmission cooler, and an HD clutch or electric fan conversion for the radiator.
If the stock MAF is being pegged by a stock 4.6L, or even a cammed 4.6L, then it's useless in a forced induction application. If not, you might be able to use it for a few PSI.
I don't know of any aftermarket MAF for the Rover V8 application, but my exposure to the engine has only been via Land Rover. I'd wager that if you reached out to some of the Rover discussion groups in the UK, they might have some meaningful insight for you if the stock MAF is a workable solution, or if you're going to need an aftermarket part.
Next obstacle is fueling. Same deal, if your stock injectors are running at peak output with minimal N/A modifications, then they're not going to hold up in a forced induction application. You'll run lean and ultimately start melting important things like valves and pistons. I don't know the flow rates on the stock injectors, but again, answering that and how close they are to max duty cycle right now will determine if they're suitable to use with the light forced induction you plan on doing. Same deal with the MAF, reach out to the Rover community for guidance here, as some of them have dealt with these questions.
If there's enough reserve capacity with the MAF, and with the injectors, then you'd probably be able to get away with a low pressure turbo setup on the stock ECU. It's been done on plenty of applications over the years, and the fact that the Rover V8 used in the DII is MAF based rather than speed density (MAP based), you have a higher likelihood of success.
On engine and transaxle cooling, you're going to want an engine oil cooler, a bigger transmission cooler, and an HD clutch or electric fan conversion for the radiator.
The following users liked this post:
dgi 07 (07-13-2015)
#10