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Newbie here, need some XR4Ti advice.

Hi guys, I currently have a turbocharged Focus, and I'm looking at a REALLY nice and clean XR to buy as an open track car.

My Focus has the Aerocharger turbo, I'm getting about 160fwhp at 7psi non-intercooled, with a Pectel stand alone engine management.

I've been looking for a track day car that I can have fun with gutting, and maybe get more power out of than the Focus. And I found this really nice low milage XR. It's an 85, 60,000 miles, and NO RUST.

It's actually pretty slow compared to my car, and I want to know what it would take to get more power out of it.

The guy selling it has I think a TC intercooler he's throwing in the deal (not installed). I'd like to get that set up, I might make it into an A/W intercooler, I'm not sure yet.

What else can you do to these things quick and easy?

I've got a manual check ball boost controller I could use.

How hard is it to get to 300hp with these things? What about more than that, can the stock motor take 400hp if it's got a good management system?

My short term goal is 300hp, and I'd like to get there as quickly and cheaply as possible. Is there a well proven recipe? I could put the Pectel on the XR if that is necessary. But I'd like to know how far you can go with the Big VAM and different computers, etc...

I've read the FAQ, and a bit of the archives. Are there any really good FAQs that really get into the details, or any webpages with really good tech?

I'd like to know specifically which computers are the best, and what you can get out of them, etc...

everything you need or need to know is right here:

http://www.merkurdesktop.com/md-index.php :thumbup:
“Man cannot discover new oceans unless he has the courage to lose sight of the shore.”


Check out both the FAQ and the FAQ forum, that will give you a great start.

Any pics of the Focus?

Rob, did you read the FAQ on the main page? THIS ONE?

Lots of good info there. Got me started a year before I even had a car.


This was really good. Basically explained most of the basics I was looking for. Is it accurate?

It seems like it's not that easy to get 300hp with just simple mods like the computer, intercooler, exhaust etc...

I'm surprised. Is it because the head is really bad?

I know the Zetec engine is really easy, it can do 300 at the wheels, with just a good turbo, intercooler and management. Stock head, cams, bottom end, etc...

Nobody knows how long it will last at that power level, but one guy did it for a while before he rebuilt. It never did fail.

I've also been looking at Porsche 944T's, and they can do 400hp without too much trouble.

Quote:Originally posted by Mosquito:
[QBI've also been looking at Porsche 944T's, and they can do 400hp without too much trouble.[/QB]
I've got a father-in-law with one with a brand new engine in it who would disagree with that statement! The only thing that was done without much trouble was when his son-in-law (his OTHER one) blew it up!

I am wondering why if it is so easy to make 300 with a Focus, then why are you making half of that?

It's really not that much different to mod a 2.3 that your motor, but yes, it takes a little more boost to blow through the head.

The stock xr should be putting down about the same power as you focus is now. Getting a boost controler on their is the first thing you should do. This goes double if it is an auto.
Justin Morgan
'85 xr4ti- 15.5 @ 91mph mod-3"dp

I'm only making half of that because I don't have an intercooler yet. I have a friend with the same intercooler, and same engine management, running 10psi and he's making 210 at the wheels. That's about 240-250 crank. Don't forget, we're boosting engines with a 9.6:1 compression ratio, so you can't blow on them too hard.

That's the limit of these little turbos we're running. They're only good for about 300cfm at 10psi.

The commonly agreed upon limit of reliable horsepower with a STOCK engine is 250-300. After that, you're really pushing it, and could start breaking the powdered metal rods.

One guy is making 385ish at the wheels with a built motor (forged rods and pistons), stock cams, ported head, t3/t4, FMIC, and a chipped stock computer.

Please, I'm not trying to insult your cars, I'm just trying to find out what these things are capable of.

I have an article about an Andy Rouse prepared race car back in 85, and he made about 300 with a lightly modified engine, stock turbo, FMIC, and a "Zytek" engine management. So, I guess it's possible.

So, can you tell me, what can the engine itself take, if you are throwing lots of boost with a T3/T4? Can the stock internals take 400hp?

I would really like to eventually drop a 2.3L Duratec engine into the car, instead of working on the OHC motor too much. That's why I want to know how much you can get out of the motor without doing too much.

Also, what about the trans? I know the T9 isn't strong, but I'm into road courses, not the drag stip. Can it hold 300hp if I'm not launching it hard?

Well, the Merkur is only making 170 crank right? I'm making 160 at the wheels, so around 180. 7psi non-intercooled. What does the Merkur run stock, 10psi? I think the difference is the CR helps the engine efficiency, and plus the head flows better.

I can't turn it up any more without an intercooler on the Focus, 9.6:1 CR won't take it.

What can you run on the XR? I've got a boost controller lying around, can you run 15psi with everything else stock on the car?

Again, I'm not trying to insult anybody, just trying to understand what this engine is like.

Are the rods and pistons of the engine forged?

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