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Mid mount Brat racer


docmidBratt
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  • 2 months later...

Update

Twin turbo engine out, wiring out.

Forester wiring out in 2 hours, engine out and in brumby.

Made a A frame type engine lifter on wheels with a electric hoist. 

So easy to put engine in and out.

Just finishing wiring

Should be easy now single turbo and manual wiring.

And now we can tune it too.

Thanks doc

 

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  • 1 month later...

Update

Took the car to a track the other day

Went pretty good, just a few little things to work on.

Brakes need sorting out, bias mainly

Found that the tyres don't get that hot (but only did 3 laps a run)

And it seemed down on power.

There wasn't much kick when you put your foot down.

300000km engine might be the problem or only running 6 pound boost.

My xsi teg is 14  seconds quicker a lap

noticed that it seems to be setup to run on gate pressure only.

The wastegate solenoid valve hose it cut and blocked off

Hose plumbed from turbo to wastegate only.

Should be running around 10 pounds.

Bit anyway stuff to work on

 

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Sounds like the boost control was having issues so they bypassed it. Maybe they ran an aftermarket boost T… who knows. 

14 psi I think is about normal for stock.

Being the foz version of the boosted EJ20 I believe they were detuned via cams and tune so the turbo foz didn’t upset the WRX owners. 

What turbo are you running? The stock sf5 GT foz turbo was the TF035. From what I understand this turbo is quite small. 

I don’t know how different turbos go in the real world yet, but a TD04 could be a good start or even a TD05. I’m sure there are many other good options for track work that others could recommend. It just comes down to what you want and how much coin you want to sink into the engine prep for a screamer. 

Cheers 

Bennie

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Thanks man

The motor is from my 1998 s/tb forester. Its seemed to pull the trailer no problem.

The turbo looks like a td04 but will have a better look in the weekend.

Also will look into the boost controller. As you say must be an issue for it to be

blocked off.

And i do have a forged block sitting at home for a later date when I

get the the handling and braking tuned a bit more.

Definitely needs a front rear brake bias system.

maybe a G16 turbo?

 

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  • 2 months later...

How's it going 

We have had the brumby at the track a couple of times now with mixed results.

Since the change to the sf5 engine out of my forester no engine problems other then running on gate. (6 psi)

And the handling need some work. but got a plan for that.

Hooked up boost control solenoid and got boost jumping up around to 5000 the solid 10 psi. Got a fix for that.

But seems really slow for a turbo 2.0.

Down the back straight its only getting to 165kph which i would expect it the be 180kph with say 190hp?

My honda with a b16b does 185kph with 185hp. There's not push into your seat.

So the handling we are going to run a stiffer front spring and toe in the back a little to force it to turn in better

as I can feel the back wanting to brake loose.

Now the problem is we decided to swap out the 1996 sf5 300000km block that through a sparkplug out the head

for the 1996 bg5 200000km block which is in way better condition.

Swap everything over, blocked up unused holes, wiring etc.

Problem is it won't start.

Now my guess is that the crank and maybe cam triggers are different?

Any ideas

Thanks doc

 

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If you didn’t swap the crank cam wheel/gear that’ll be the issue. If you’re using the SF5 heads you’ll already be using the matched cam wheels, otherwise the LHS inlet cam wheel needs to be swapped for the SF one. 

But I reckon it’s that crank trigger wheel that’s the issue. 

Also look into the details about the GT forester setup that’s detuned compared to the same block and heads used in the WRX model of the same years. I believe there are differences in cam specs, tune and obviously the turbo (TF035 vs the TD04). It could be worth playing around with cams, ECU and the turbo for a better factory setup. 

Loads of info out there, I could be wrong as it’s not something I’ve followed up on as I don’t have a reason to. 

Cheers 

Bennie

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21 hours ago, docmidBratt said:

How's it going 

We have had the brumby at the track a couple of times now with mixed results.

Since the change to the sf5 engine out of my forester no engine problems other then running on gate. (6 psi)

And the handling need some work. but got a plan for that.

Hooked up boost control solenoid and got boost jumping up around to 5000 the solid 10 psi. Got a fix for that.

But seems really slow for a turbo 2.0.

Down the back straight its only getting to 165kph which i would expect it the be 180kph with say 190hp?

My honda with a b16b does 185kph with 185hp. There's not push into your seat.

So the handling we are going to run a stiffer front spring and toe in the back a little to force it to turn in better

as I can feel the back wanting to brake loose.

Now the problem is we decided to swap out the 1996 sf5 300000km block that through a sparkplug out the head

for the 1996 bg5 200000km block which is in way better condition.

Swap everything over, blocked up unused holes, wiring etc.

Problem is it won't start.

Now my guess is that the crank and maybe cam triggers are different?

Any ideas

Thanks doc

 

Glad you're getting it out and using it.  I'm sure we'd all love to see more pictures of it in action.

I don't know much about Subaru turbo engines so I'm no help there.

With equal power I wouldn't be surprised if the Honda is faster on the straights, it's probably lighter and has less air and drivetrain drag right?

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So update after todays work

The cam and crank triggers are the the same between both bg5 and sf5.

Have power going to coil pack

Have checked coil pack and tested it. working fine.

Cranks over easy but still no spark.

Got good earths, added a few more to make sure.

checked all plugs

Bit off a loss now.

Didn't check igniter, don't no what im looking for ha ha ha

Yea i only have iphone on a prepay system do not connected to net to post pics from track

but my wife made a instagram account and put something on it but i dont no what

But next time i'll get some shots and a flick or 2

Thanks doc

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22 hours ago, docmidBratt said:

So update after todays work

The cam and crank triggers are the the same between both bg5 and sf5.

Have power going to coil pack

Have checked coil pack and tested it. working fine.

Cranks over easy but still no spark.

Got good earths, added a few more to make sure.

checked all plugs

Bit off a loss now.

Didn't check igniter, don't no what im looking for ha ha ha

Yea i only have iphone on a prepay system do not connected to net to post pics from track

but my wife made a instagram account and put something on it but i dont no what

But next time i'll get some shots and a flick or 2

Thanks doc

Do you have some kind of OBDII scan tool / app?  Might tell you something, at a minimum whether the ECU is coming on.  Is it getting fuel?

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  • 2 weeks later...
  • 3 weeks later...
  • 2 weeks later...

Took it to the track for the clubs summer series.

Upgraded the front springs to 450lbs.

It made a difference, way better under braking and better through the corners.

Still not quite where I want it.

Unable to really push it coming into corner but more steady in the rear than last track outting.

Results 

Qualifying , the little sleeve of rubber that goes over the throttle cable slipped down

and got caught in the throttle and jammed it on full throttle.

First race made up a few spots

2nd race reverse grip got more confident with the handling ended up in 3rd but the 2 guys

in front of me broke out, so 1st for me.

3rd race handy cap based on lap times. Flag drop per group

So might be 5 second behind the slowest car the next flag drop and

maybe another 5 second to the next flag drop and so on. 

Slowest first off and fastest last.

Got 1st in that race but broke out on the last lap by 300s of a second

Now it not fast yet and I'm in the slowest class, but under full boost I can

feel it will be allot quicker.

Problems

Apart from the bit of rubber throttle jam up

only one other problem. The same as last time.

The boost fluctuation. jumping between 6 and 10 psi under load.

Sounds like the clutch is slipping.

We changed the boost solenoid but didn't fix it?

Check for leeks this weekend

Anyway a fun day had by all

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  • 2 months later...

Been a while from last update. Sorry

Took the brat to the track for the last round of the summer series.

At this point I was coming 3rd and with all the teething problems you get from a new build.

Mainly with the boost soleniod not doing what it should.

So just put a manual tap on it and added a 02 gauge to keep an eye on fuel ratios

Started with 6psi qualifying then to 8psi for first race.

Starting to go like it should but noticed it slipping the clutch a bit at the end of the race.

Only 9.6 on the 02, so really rich so cranked it to 10psi.

No good the clutch was pretty much stuffed on the warm up lap.

New clutch only done 2 practice events which the car wasn't even going propalley,

2 qualifying runs, so just warm ups and a fast lap.

5 of the 9 races.

So disappointing for a upgraded clutch, but was running 3rd out of most corners so lots of torque.

Will have to save up for a really heavy duty one.

But anyway just an update for those who are interested in whats been going on.

 

 

 

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  • 6 months later...

Update

New clutch

Ecu swap out of the question at the moment.

Plug on harness is a 3 plug all 4x9. very unusual.

So would have to trace all wires back to ecu and fit wire in harness. not keen to do

So ill look for a gc8 harness for an upgrade so a link will plug in.

So took it to dyno to sort fueling out.

You see the car doesn't even get that hot at the track

Say tops I've seen is 76 degrees manly because of the richness of the fuel. 9.60

So about 10kw down there.

So mucked around with it and got a better afr and ended up with 138 at wheels on 9psi.

I wanted to turn it up to 12-14 psi but they didn't want to because they didn't new the engine.

But I'm fine with that.

missed the first round of the summer series here because it was pissing down.

Don't do rain, no fun for me and a waste of money. $270 entry plus petrol, NZ 100 octane $3.20 ltr

Anyway I need to go see a friend of mine and talk about setting up the wheel alignment to

force the car to turn better without losing the rear end.

He's a racecar fabricator plus has work in wheel alignment shop setting up racecars.

Will start from there and see how it goes

I'll work on getting some videos up at some stage for ever one to have a look at.

Have a good xmas all

 

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