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245 GL -90 "B6284T" and other 6-cyl builds


Active member
May 23, 2015
Fuse brought this up in here and I thought that perhaps I could do a summary about it. It'll be a bit long, I admit.

Some short basic info first, better specs lower:
Originally B200E, AW70 and 1030 rear. Almost top notch equipment which means electric front windows :oogle: Came to Finland from UK about 10 years ago along with the owner. I bought it 2010 only because of the good body. Aand since then it has been only downhill, for my wallet at least.

After buying:


First changes in 2010 included interchanging front brakes, suspension parts and axles with previous daily driver, 242 -81 2,46l 16V with Eaton M90. Rear got Truetrac inside. Some pics here.

2011 included converting from RHD to to LHD with parts laying around, some rust removal from frontend and assembling and fitting in B6254 with B6304 crank. Therefore "B6284T".
2012 came with Kaplhenke topmounts with an extra spacers to set the height correct with old shortened springs. 2013 got suspension mods, gearbox changed from M90 with 2-plate clutch to BMW GS6-53DZ with -765 SRE and stiff sintered plate.
Some 2014 and 2015 pics.

To the specs part.
First pics of engine build, fitting, etc. here.

Evo 1, year 2012. Engine bay pic.
- Stock B6254 block, B6304 crank and 204hp cams, stock T6 pistons, H-rods.
- Stock RWD intake manifold, self made exhaust manifold, B6304 head with basic valve job and mild self made porting, 50mm HKS-style wastegate, 70mm dump from previously mentioned 242, basic 400x300x76 intercooler.
- HX40 Super #17 exhaust, 3,5" dp, front silencer and over the axle 3", rest 2,5".
- MS1 V2.2, boost 1,5-1,6bar, fuel 98 octane, 683cc Siemens injectors, 044-copy pumps, RWD coils.

523hp @ 5360rpm
704Nm @ 5080rpm
In print. Boost was ~600rpm late compared to normal driving. Dyno vid.

Stangind mile with 1,3bar boost 156,8mph/251km/h in 2012. Incar vid.

With this version I broke one M90. Both gearboxes got some nice lovin' in the track :rofl: Also broke one piston with a settings mishap. And in the end a rod bearing and crank when an oil seal gave up in full pull and I didn't notice it until oil pressure light lit. After this I took engine apart and car stood in a shed for a year.

Evo 2, year 2014. Only changes to previous mentioned.
- Pistons Wiseco 81mm with 9,5 comp from Flatlander-Ipp. Lasted under 10000 miles, then cracked.
- Compression 9,5, KKK 31, boost 2,1-2,2bar/~31psi
- 1260cc SMP disc injectors, MS2 V3, fuel E85
- 3" exhaust till the end
- T6 block and crank, stiffer valve springs.

727hp and 870Nm

Dyno vid.

The goal was to barely reach 700hp but it came so easily. Didn't even need better cams or such. Cams have a small timing change from stock to take torque higher and they have been on the same setting since this dyno. Nice engine to drive over winter.

Evo3, a couple of months ago. Engine bay pic.
- Still Wisecos, some time after this they broke.
- 3,5" exhaust from start to finish going over rear axle :)
- Aftermarket fuel rail, boost 2-2,1bar.

789hp @ 6601rpm and 935Nm @ 5485rpm

Head gasket blew some time after dyno. Propably done over time with bit too much ignition advance. After changing gasket, I fought a while with ignition. Changed new plugs, basic BCPR7ES with 0,65mm gap and updated to T6 coils. Wasted spark. First pull with everything working great, got some speed on 4th gear and then it blew the gasket again. This time reason was that thread in block gave up on one bolt. I had to put a threaded steel sleeve in there after failing to drill broken head bolt correctly out. Nothing new to snap a head bolt while first time opening a 81mm bore B6xxx engine. Has happened now five times with the same bolt on exhaust side between cylinders 4 and 5. And all have not been opened since leaving factory.

Evo 4, last thursday. Though this is a lamer version but the latest as well.
- 4" dp, Griffin 24x19" radiator, Garrett 24x12x3,5" cooler, all changed in hopes of getting a new dyno results with previous engine.
- Stock T6 pistons, boost 1,8bar

Almost no power :roll: 699,985hp and 843Nm.

Some other specs for now:
Fuel system: 2x K-jet copy pumps, 12mm line from tank to pumps and 10mm line from pumps to engine. No catch tank, no prepump.
Body: No mods, yet. Added upper and lower supports to engine bay of course.
Powertrain: Gearbox BMW GS6-53DZ 6-speed. Billett flywheel, clutch -765 M5 SRE with stiff 4-plate disc. Stock driveshaft, stock 3.31 1031 rear with Truetrac.
Suspension: Gaz adjustable shocks all round, polyurethane bushings, strengthened front control arms and rear upper too. Coil springs front, basic shortened lowering spring rear. Front sway bar 24mm, rear 19mm. All control arms and engine beam(or whatsit) hot-dip galvanized.
Brakes: Front 00-> T5/etc. 305mm discs and calipers with custom spacer. EBC TurboGroove disc. Rear stock disc for now. Yellowstuff all round.
Wheels: 215/45/17 and Polaris(got two sets, like new and a bit shabby)

And to the latest event, standing mile yesterday.
Made an extra front lip Friday/Saturday night for trying to get less air under the car. And propably to lessen the airpocket effect in engine bay which these have quite badly. Lowered the body 1cm. Front lip helped a lot on the road with heavy sidewind. Decided to tape front decently to prevent stuff taking off. Luckily got a pull before the rain. Calm start, nice clean pull and before the finish started to wonder why does it feel like I've hit revlimiter(7400rpm). After checking the results it felt like it because it was hitting it.

Expectation for barn door aerodynamics were not too high, around 172mph/270-280km/h. Surprise was quite huge with 188,75mph/302km/h. In the end car was clearly lifting. Have been thinking about 3.15 rear and putting 225 tire to the back(got two semislicks waiting). It could be just enough for 200mph/320km/h but it requires also more aero mods.

The whole thing: https://www.youtube.com/watch?v=02hv4d2bkiM

Not good looking but working:

When this has not been standing due to lack of motivation or some miscannelous stuff, it has served as a daily driver. Occasionally some hauling but mostly driving to work and other places. After last fall I have driven around 17000km/10600miles. Before current engine it has seen some trackdays

Everything has been done by me, except machining and aluminium welding. I have gotten good advices from a few friends who have more experience in powerful engines, this began as my first turbo build. I had done two supercharged 16v redblocks with decent success before. I'll write some smaller things afterwards. I'm not even trying to write down everything what has happened with this, it would take far too long and everyone would be bored.

Propably got something wrong, will correct later.

If any questions, please do.
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What, no engine bay shots! Don't make me have to go to the inspiration thread! Super clean car, polaris look great on it!
What, no engine bay shots!
Yes there are. Or was one, link after text: Evo1. That was the first version with HX40.
Added second link to latest version after text Evo3. And now it's also here:


And if anyone is wondering my username, it's a finnish nickname for 2x4 wood. Based of course to the body shape :)
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Nice car! I am surprised that you can break transmissions, but the rear axle lives with all that power
Have not had any rear problems due to power. I just drive too nicely, I think... Had a Ford 8.8 with 3.07 ratio ready for this but sold it after Wisecos gave up. It was purely thought for some 1/4 mile pulls and it would have given better ratios for standing mile.

Great car! :)
I'm guessing it isn't road legal in Finland? :-P
I'm sorry but no win there for you :) I like to keep my cars papers in order according to what they have in. Hasn't been a problem yet with any of my builds. All cars in my vids for example are road legal. You'll just have to make a street tune for acceptable power. Better ask questions first and prepare for it.
Not easy to change the swing direction of the windshield wipers, eh?

Looks like the "cowling" panel below the windshield has the wiper holes in different places?
Yeah, it's not too easy and why bother anyway. The whole section between windshield and firewall has to be changed for that, inside and outside.

Did a quick check after work. Nothing out of ordinary, some small oil leakage from gearbox. Propably through breather.

Forgot to mention that I have used feeler gauge strips in the small waterchannel between cylinders to give support. Thickness 0.8mm/0.0315". And Valvoline 10W-60 VR1 as engine oil.
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lovely, i am making quite the same as your first evo :)
It's a good basic build and can make decent power and nice torque reliably. According to what I know, B6254 block is good for 600-650hp at least.

When you have some nice figures you'll just want a bit more :) I was going to try 850-900hp out of my previous version with 4" dp and Garrett intercooler before pistons broke. That would have been just something else, torque estimate around 1000Nm/~737lb-ft. :-P But that's that for now.

Forgot to mention wideband in the specs before, it's Innovate MTX-L.
Few updates here, I'll just blurt it out.

Bought two Federal 595 RS-R 215/45717 semislicks for front and earlier bought two Nankang NS-2R soft 225/45717 for rear. Now second Polaris set has these. At least they're cheap and seem to be working ok.

I have begun trying to make bottom of the car more aerodynamic. Front lip was great success even it's not so accurately shaped. Last saturday started with the front. Used "a couple" of hours to make pieces from sheet metal. It looks ok but would need high speed testing. Got to do the rest and try out later in a standing mile event. Then we'll see if it'll fly or not :oogle: Attaching is made completely with bolts, I'll try to simplify it even more for faster attaching and removing. Not going to keep it hanging when not needed. At least not in front because it's so low. As on standing mile the weight of the car isn't a decisive thing, I'll propably will make everything from sheet metal at first and then decide if I'll change it to aluminium.

Here's one pic:

And the rest are here. Just keep going to the right to see all.

While scrolling pictures in the last link, you'll see the new "fancy" breather can I did in the meantime from 3,5" pipe. A bit big and needs better support but it fits in.

Took it to the local track(Motopark Raceway) last Sunday with 1,5bar boost. Tire pressure was clearly too high, have to set it lower next time. Federals kept up nicely cold and hot but Nankangs were in trouble after getting hot in a couple laps. And a bit when cold as can be seen in the video taken outside and in the end of incar vid. I had all front bottom parts on while driving, at least didn't make it worse but speed was only ~230-240kph/145-150mph before braking on the back straight.

Short shots from outside, a lot windnoise. Didn't think it sounds so nice outside, first time hearing it myself: https://www.youtube.com/watch?v=oDWHorWC8Xo
Incar: https://www.youtube.com/watch?v=vuG-BxreJHc

No problems, though did shave off over 3 second of previous best lap time with this car :rofl: Practically only because higher straight speed. Didn't take corners that hard and first time since last year. And just as a quick notice, I have power steering rack and ball joints but no pump, so it's a bit stiff but I have taken keen to it. This track suits this kind of car nicely and I didn't think that correct gear would be so easy to find to different situations. Would need even wider ratio for rear in some places and I'm on the look for 3.15 rear. It would be good for standing mile too and that's the main reason for it.
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That looks properly quick for skinny tyres and no cage. My heart rate went up watching the in-car at 3:15 when she stepped out on you through the small kink on the back straight. I would've needed to lay down after that.
I have been thinking of making a "cage" somewhat integrated in to the body. It is daily driver still, I want to keep it almost stock outside and it occasionally needs to seat more than one or two.

Not the first time to have a little slip on track so it wont scare me. Several years ago lost control of 242 in the same back straight corner on wet. Did a complete 360 spin ending up on to the gravel left of track. Speed was around 160-170kph/100-105mph. Small bump in the inside which helps, at the same point it tried to take off now too. For me the first one in the video was more surprising :) Just gave gas too early.