07FocusST Home Turbo Build

[07FocusST]

If it hasn't been known by now that there only a few companies that market turbo systems for the Duratec Focus. A few members here and myself aren't willing to pay $3,000-$4,000 + S&H for a pre-fabbed kit. Some of us just want to liberty to say "yea... I built it myself".

Thankfully FF has some people with a great amount of knowledge (or balls) to make their own systems. I personally want to give a BIG shout-out to Sporadic for taking the time to post all of his information and pictures here on FF for all of us to study. Without his inspiration I probably wouldn't even consider attemping to build my own system.

With that out of the way I will list all the parts I will be using during my build:

- IHI RHB52 from 1987-1988 T-Bird Turbocoupe
- 60lb/hr Siemen Fuel Injectors w/ C-F-M Adapter Harness
- 2.5" Universal Front Mount Intercooler 24" x 7" x 3"
- 2.5" Intercooler Piping & Silicone Couplers (Turbo-to-Intercooler)
- 3.0" Intercooler Piping & Silicone Couplers (Intercooler-to-Throttle Body)
- Pre-Fabbed 2.5" Intercooler Pipe w/ HKS SSQV BOV mount
- 3.0" Blow-Thru MAF house w/ 2005+ Mustang GT MAF sensor
- JGS Turbo Manifold
- SCT Flash Tuner
- Oil Supply Line w/ Adapters & .06 Restrictor
- Oil Drain Line w/ Adapters & Oil Pan Weld-on Bung
- 2.5" Home made Downpipe Assembly w/ 2-O2 Sensor Bungs
- Oil Catch Can

** Equipment for Later **

- A Pillar Gauge Pod
- Boost/Vac Gauge
- Electric Oil Pressure Gauge
- Electric Water Temperature Gauge
- Wideband O2 Sensor

The plan is to run my Turbo System at a low PSI to keep things safe. I am running my setup to utilize a Blow Off Valve. Heck, if you have a turbo system then you probably would like to hear it. I know I would.

I am using the HKS SSQV because of their high reputation. The RHB52 turbo can be hard to find replacement parts for so I would suggest to everyone who considers building your own project to look for the T3 turbo used in the later years of the Ford SVO/TurboCoupe or even the Merkur XR4TI. This will save you a big headache if you run into the same problems I have.

Some of you reading this are probably wondering about a few things, so I will answer a few before I post some pictures:

"If the IHI RHB5 is hard to get parts for, then why didn't you purchase the T3 Instead?"
Simple, the T3 is even harder to find used because they are universal. There are a million places that carry parts for it. The T3 may be bigger in size but I feel safer starting with a smaller turbo.

"I have been told that running a BOV on a car with a MAF style computer system can cause engine damage."
This is absolutly correct! Running a BOV after a MAF sensor will make your engine stumble & stutter because all the air that has just been "metered" has now been released into the atmosphere. The computer doesn't recognize this and will continue to allow a high amount of fuel to enter the engine while there isn't an adequate amount of air to compensate for the extra fuel. In other words your engine will be extremely rich. If a BOV is placed before the MAF sensor then there won't be a problem because the MAF sensor hasn't metered the air yet. That also goes to say that if your engine's computer system relies on a MAP sensor then you can run a BOV regardless because the MAP sensor reads the Vacuum/Pressure inside the Intake Manifold. So there isn't any problem this way. The other way to run a system is by doing what most Manufacturers do. They run a Diverter valve that recirculates the air back to the turbo inlet. This is typically the safest way to run any turbo system.

"If you are running a BOV before the MAF sensor then that would mean you are placing the MAF sensor in the compressor's outlet side?"
This is also correct. This setup requires a particular type of MAF sensor housing known as a "Blow-Thru MAF Housing" which isn't what most vehicles use as OEM. Most cars would use a "Suck-Thru" MAF housing like a factory MAF would be on a Focus. The only difference is the suck-thru has air being sucked thru and the Blow-thru has air pressure inside of it and usually is secure to a pipe with a strong clamp unlike a suck-thru.

"Why don't you use the DiabloSport MAFia instead of a Custom MAF housing and Mustang GT MAF sensor?"
Well... that is because I plan on using the BOV like I mentioned before and this requires me to put the housing in the pressurized side (blow-thru). So I would need a new housing regradless. I suppose I could use my factory MAF sensor with the MAFia, but the Mustang GT MAF is good to around 400HP. If I even come close to pegging out the Mustang MAF sensor then I still have the option of using a MAFia.


So here is what I have so far. There are alot of parts on order and I am lucky enough to have a good friend to let me use his MIG welder that has Argon purge. Please keep in mind that this is a work in progress!!! Thanks, enjoy the pictures!

The good:

[Sponsor]

[07FocusST]

The Bad: The Impellar looks like it had contact, the bearings are shot! Bottom pictures are a few random picture I took of painting the compressor housing, the paint I used, and my Focus!!!

[y2kc0wb0y]

How much money did you save?

[1turbofocus]

Originally Posted by 07FocusST

The RHB52 turbo can be hard to find replacement parts for so I would suggest to everyone who considers building your own project to look for the T3 turbo used in the later years of the Ford SVO/TurboCoupe or even the Merkur XR4TI. This will save you a big headache if you run into the same problems I have.]

I dont agree, These turbos on the Focus engines dont work well and in most cases are wore slap out when you take them off the car , I think with the low prices of new turbos now with 1 year warranties at less then 600.00 you should allways buy a new turbo

Originally Posted by 07FocusST

"I have been told that running a BOV on a car with a MAF style computer system can cause engine damage."
This is absolutly correct! .]

This is incorrect , you WILL NOT damage your engine

Originally Posted by 07FocusST

Running a BOV after a MAF sensor will make you engine stumble & stutter because all the air that has just been "metered" has now been released into the atmosphere. The computer doesn't recognize this and will continue to allow a high amount of fuel to enter the engine while there isn't an adequate amount of air to compensate for the extra fuel. In other words your engine will be extremely rich. If a BOV is placed before the MAF sensor then there won't be a problem because the MAF sensor hasn't metered the air yet. That also goes to say that if your engine's computer system relies on a MAP sensor then you can run a BOV regardless because the MAP sensor reads the Vacuum/Pressure inside the Intake Manifold. So there isn't any problem this way. The other way to run a system is by doing what most Manufacturers do. They run a Diverter valve that recirculates the air back to the turbo inlet. This is typically the safest way to run any turbo system.]

This is correct to a point there is a way to adjust the ECU so that you get a slight rich condition but dont notice a thing from the drivers seat , A blowthrough is the ideal way of doing this and all Focus kits now should be blowthrough

Originally Posted by 07FocusST

"If you are running a BOV before the MAF sensor then that would mean you are placing the MAF sensor in the compressor's outlet side?"
This is also correct. This setup requires a particular type of MAF sensor housing known as a "Blow-Thru MAF Housing" which isn't what most vehicles use as OEM. Most cars would use a "Suck-Thru" MAF housing like a factory MAF would be on a Focus. The only difference is the suck-thru has air being sucked thru and the Blow-thru has air pressure inside of it and usually is secure to a pipe with a strong clamp unlike a suck-thru.]

Incorrect any MAF can be used as a blowthrough the MAF does not know or care if the air moving through it is being pulled or pushed

Originally Posted by 07FocusST

"Why don't you use the DiabloSport MAFia instead of a Custom MAF housing and Mustang GT MAF sensor?"
Well... that is because I plan on using the BOV like I mentioned before and this requires me to put the housing in the pressurized side (blow-thru). So I would need a new housing regradless. I suppose I could use my factory MAF sensor with the MAFia, but the Mustang GT MAF is good to around 400HP. If I even come close to pegging out the Mustang MAF sensor then I still have the option of using a MAFia.]

The GT Mustang MAF is odd size and hard to get hoses for and looks like crap installed on top of that it is to big and you dont get as good a signal in part throttle , you would be better off making you or buying a 3 inch MAF tube and using your stock Focus MAF electronics

Tom

[Power Surge]

Wow, I have to admit, everything you said is right on the money. You've really done your homework. I am impressed.

The only thing I would change is your choice of turbo. I would really start with an internally gated T3 based unit, not that IHI deal. I've deal with the IHI units for a long time on Turbo Coupes and such and they are just a waste of money and energy IMO.

Great choice on the MAF setup. The 05-up cartridge sensors are very blow through friendly. Mounted in a 3" tube, will be a nice clean setup, and you won't need to recirc the vented air if your bypass is before the MAF. Just make sure you've got a few inches af straight tube before and after the sensor for a cleaner signal. I did the 05-up in the blow through tube on my turbo SHO. I intergrated mine as part of the actual ducting. You can see it here pointing towards the strut tower:



I still needed a MAFia for my setup, but you probably won't on the Focus. Either way, it can be added if needed.

Also, you don't need injector adapters, they make 60s with the EV1 connector on them. Get the Motortron ones, plug and play.

I will be watching your build to see how you progress with it. Good luck!

[07FocusST]

y2kc0wb0y

I am in the process of collect all the parts, so far I am guessing a total amount of around $1000-$1200 total spending depending on what I buy.


1TurboFocus

As I stated earlier, The point for my home build is to save alot more money than buying a kit. So with that in mind I definitally would stick with the IHI IMO.... Granted you are absolutely correct about a new turbo. It should always be considered when making your own kit. It is personal preference and probably going to rely on how much $$$$ you have at the time.

As for a BOV damaging your car, I have seen more Subaru's & Mustangs with blown engines because their engine was not properly setup for a BOV. When the engine goes rich and the driver hits the gas there is alot of mayhem going on inside the engine because now it is trying to clear the excess fuel, then goes lean and right back to a stoich/rich amount. This is why you see a lot of lightning drivers blow their engines is because the roots style blower can surge and cause this situation to occur.


I agree, blow thru should be the way regardless

you are correct about any MAF being used for a Blow-Thru setup, but keep in mind that a 3" MAF house will give the best reading in any vehicle. Running my stock 2.5" plastic MAF housing will scramble the signal a little and the fact that it is plastic with pressure behind it doesn't thrill me at all.

Again, you are correct. The stock MAF housing would not fit. Maybe I didn't state this but I am going to be using a 3" Blow Thru MAF with a Mustang GT Sensor that is good to 400HP.


PowerSurge

Your setup looks awesome. I like how you integrated the housing into the piping. I have already bought thr Siemens 60lb/hr. I took a look at my injector harness last night and it looks like the will plug in without an adapter from CFM.

[1turbofocus]

What ever , I was just passing on what I have found that works on the Focus , It is a Focus we are talking about here not a Suburu or Mustang and in no way can you damage an engine from venting metered air

No I dont agree that " a 3" MAF house will give the best reading in any vehicle" There are many I tune that the 3.5 is much better and 4 inch on some of the higher HP V8 cars , you need to choose the smallest tube to get the job done with the range needed , Its your car and you have to choose but the Mustang GT sensor in a 3 inch tube I doubt will get you to 400 on the Focus

Tom

[mbx5brian]

good luck

[1turbofocus]

Originally Posted by Power Surge

Great choice on the MAF setup. The 05-up cartridge sensors are very blow through friendly. Mounted in a 3" tube, !

I havent found the Cartridge sensor to be any better the the old style with doing back to back testing , the signal wasent any cleaner or smoother , I am getting some calls to change over to that sensor and just wanted to add that in here

Tom

[1turbofocus]

Originally Posted by 07FocusST

y2kc0wb0y
you are correct about any MAF being used for a Blow-Thru setup, but keep in mind that a 3" MAF house will give the best reading in any vehicle. Running my stock 2.5" plastic MAF housing will scramble the signal a little and the fact that it is plastic with pressure behind it doesn't thrill me at all.
.

I was just trying to correct what you said earlier "This setup requires a particular type of MAF sensor housing known as a "Blow-Thru MAF Housing" which isn't what most vehicles use as OEM"

Tom