Bf Mk2.5 Home Build - 309Rwkw On 15Psi

[IT15ON]

Hi Guys,

I have been poking around the forums for years, but only recently has my journey begun. Started out with a non turbo BFmk2 - but sold it and got what I really wanted, the MK2.5 turbo!

A few photos of how it looked when I got it:

I am sure a few of you can pick that it started life as a cop car. I never thought I'd go for one of these but the car presented very well and had an owner who treated it well. The cop cars get serviced on time and I figure parts like suspension/brakes which get a hard life need replacing by now anyway.

I still had my old NA falcon at the time, and the market for a used NA was not very strong. So while I still had both I did a few things like swapping my number plates over, swapped my 18" rims on to the turbo, and swapped one good headlight off my old car onto the new one which had a leaky light. I couldn't stand looking at it like that any longer....

I was enjoying the result, but the dream from the start was to run the factory (non cop) wheels and of course get some tint to finish the look. I ended up finding some wheels interstate and got the tint done, and was much happier with the result

Took it on a cruise with a few like minded people...

I drove it like this for a while. Fitted the usual after market oil feed line for the turbo, K & N filter for the airbox etc. The car came with a tune (done at a professional workshop) along with an exhaust and BOV. One hot summer day I heard audible ping and lost faith in the tune that it had. Went in with a mate to purchase VCM suite and he worked on a safer tune to run for a while. In the end both our cars were running close to an F6 tune, he was a bit more aggressive with his tuning as he had the gear at home while mine was just set to a safe level as I live further away. This was going well for a while and keeping us both entertained.

A written off XR6T was spotted for sale and then bought, thinking parts would come in handy down the track for mine or his cars. It also had a couple of goodies which would end up on our cars....

He fitted the exhaust to his car, and it all sat for a while. I found myself not needing a car for a while over christmas, and it needed a fair bit of maintenance.. This was when things more serious with my car...

Edited 25/02/15 11:33 PM by IT15ON

[IT15ON]

The next step. I set out to build the car to be capable of 330-350rwkw with the right tune and boost. Being the later model it has the strong bottom end etc and should be safe to do so. I didn't want to spend stupid amounts of money being an older car and I have other budget issues (such as a house one day maybe?! and my S13)..

The shopping list was made and then kept growing on and on. I'm sure you all know how it goes.

First up - the diff needed a rebuild as it was leaking badly, so out it came and got some fresh bushes at the same time.

The ZF needed a service and was done at home after some bad experiences paying shops to do it.... Nulon SYN ATF went in along with a filter kit and a new electrical connector sleeve as it was leaking. This stopped all leaks. It then had to be driven to work a few times to "learn" about it's new fluid. All was fine except under full boost there was a massive kick. This turned out to be the wastegate actuator diaphram which was perforated. There was already a new actuator and flapper valve on the bench to go in, so this skipped to the top of the list.

Turbo came off....

And the usual porting job was done at home and fitted the new actuator (12psi spring) and flapper valve. It also got some new studs on re-fit as we all hate the stock ones!

[IT15ON]

While all the piping was off you may as well do the intercooler and intake setup!

The cooler was removed from the written off car and fitted to mine. It was in fine condition and had hot and cold side piping. This required a new mounting for the cooler as it was a bit rough in the other car and of course minor cutting here and there. The process west under battery intake also went in, and a new PW blow off valve (plumb back. I wanted to stick with a reasonably stock look for the car, and avoid attention from the po if possible, so everything was painted black.

[IT15ON]

Plenty of air going in now, but how about fuel?

The wreck was kind enough to donate some 60lb injectors, but it was running a surge setup which wasn't really the way I wanted to go. After a bit of research the DW300 was considered good for the job, and we have used before in nissans with good results. Fitting it into the original cradle was one of those jobs you wish you didn't start on a school night, but all ended well in the end.

[IT15ON]

What's going on under there?

3 guages were fitted to the dash, being oil temp, boost, and wideband AFR. The stock look again was important, and a lot of research done to find something that would look the part. Cobalt's came very close, but in the end these ones got the win.

Planning on tuning at home the wideband was by far the most important tool. It is also able to send data back to VCM suite for logging during tuning. The whole guage setup cost a fair penny, but when it is providing data for tuning then it is worth the effort. They also look the part and I have to face them every day!

[barnz]

Awesome stuff mate haven't seen a thread like this in a lil while...I feel like there is more to it though? What happened after fuel pump?

[IT15ON]

Thanks Barnz, more coming, just trying to get all my pics together and type faster!!

Last step before getting back on the road for a tune was the front end. The original shocks were pretty tired and my rotors warped as hell. It was terrible on brakes before the work.

Some bushes were previously done along with ball joints because of wear, but the rest got done at this point along with bilstein shocks all round and some new brakes. I left suspension at standard height for handling/geometry/bottoming out in town reasons despite wanting to lower it for the look. Had to remember that it is a daily driver and at the end of the day practicality is still important.

The new brakes are DBA 4000 series T3 front and T2 rears. QFM HPX pads all round too. As far as I could find this would be best thing I could get before spending big money on brembo etc.

I love the look of the new gear, and the bilstein colours look fancy

The front calipers were looking very tired and so got a rebuild at the same time, this wasn't part of the original plan but was necessary when the brake fluid came out looking rather like used oil......

Cops must have given them a hard time - I only put around in it

[Ralph Wiggum]

Nice write up mate, doing all the right work in all the right areas.

Boost seems a little high for the power level tho?

[IT15ON]

At this point Tim had been doing a lot of research and gathering injector data etc, tuning cruise and driving to work to iron out any teething issues. Over the long weekend was the only opportunity for me to get away from work and tune the car, so it had to happen then. We purchased Kmon 2 knock sensing/monitoring gear and set it up to log with the rest of the data in VCM. From here it was a long two days of pulls on the street getting the tune good enough to drive home. We ran out of time, but got something good enough to do the job. Car was still running gate pressure only (12psi) but this was enough for now.

A few weeks later and a lot more research and it was time to have another go. I set up all the gear and drove, while tune changes were made remotely using team viewer. Tim controlled my laptop from his desk at home while I drove and we were in phone contact. It was an interesting experience. This day was nothing too serious - not adding any boost or timing, just smoothing some fuel here and there, so was considered safe. Knock was always monitored and I could constantly watch AFRs as I drove.

Then, broken:

No actually all was fine. Touch up was finished and drove it for another couple of weeks. Wasn't perfect but was close.

An opportunity then came up for a touch of very cheap dyno time. It only came up 2 days before, so work started to get ready. Everything was pretty good but then Tim found correct injector data only the day before. We met up and tuned until midnight on the street and got it looking very ready for the dyno. Hadn't pushed hard for power at this stage, just getting fuel etc perfect for the day. After waiting a very long time to get on it ran 268rwkw on the street tune.

Only one hour of dyno time was managed for the day which was pretty disappointing, but considering we got it as a favour it was fantastic to get a run at all. In that hour a bit of timing and boost was added, to get the final result of 309rwkw. This was on around 14.5psi but the valvesprings weren't up for the job at around 5,800rpm plus. Dyno time ran out but this was a good result time considered. Tune still needs a polish but a great drive for now...

After coming off the dyno boost right up top was reduced a touch to save valve float and this is where it sits now. Hopefully we will get to polish up the tune a little, then I will do valve springs and run more power eventually.

I was getting very keen for a run at the drags at this point, and purchased some ET streets on steel wheels for the job. Headed down to run at WSID settle the score last Sunday, hoping to get to a mid to low 12 sec pass. I have wanted to run at WSID for years, after racing other cars at 1/8th mile drags at regional meets such as Gunnedah.

I was absolutely pumped.

Got through scrutineers, and lined up, rain spitting.....

Rain delay once in staging lanes, then got to here.... Rain delay again

Racing again, then more rain,

And that is as close as I got. Rain settled in, meet cancelled.

Heartbroken I packed up, and took my car to a downshift meet before heading back home.

I was hoping to get a nice burnout photo by the professionals down there, well I got this one anyway lol

Better than nothing.

And that brings us to today. Hopefully I will run at the drags soon. Next steps are to finish the tune, change my BOV setup as it is way too loud and VL spec (may try stock bov??) and then do valvesprings and more power.

Hope to see some of you all on the street or at the drags!

[IT15ON]

Nice write up mate, doing all the right work in all the right areas.

Boost seems a little high for the power level though?

Thanks mate.

We did a compression test beforehand came up fine. Valvesprings have found their limit where it is now. Ultimately with a bit more dyno time it may cop a little more timing at the same boost to make more power, but we just ran out of time. What would you expect with this setup?