Author Topic: Yoof's Turbo  (Read 108270 times)

Offline AdzCM

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Re: Yoof's Turbo
« Reply #345 on: March 14, 2014, 01:10:24 pm »
I just went through your build thread again [top quality] and I've just noticed that a con-rod failed on you  :o That would devastate me.

You think the con rod bolts were to blame? How old where they? I'm starting to panic thinking I should have uprated my con rods to pec rods too.

Also, what would the difference be between the gt2554r turbo and a k04-023 turbo? Which is bigger? Much lag with the gt2554r? Also, what camshaft are you running?

Awesome work on the gearbox adaptor plate  ;)

Offline Yoof

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Re: Yoof's Turbo
« Reply #346 on: March 14, 2014, 03:30:23 pm »
Thanks- hard to say what went went first for sure, but I'd guess the rod, the engine doesn't rev much more than stock (only 200rpm more) and the pistons are a fairly similar weight to the cast stock ones, however my cylinder pressure is far higher than standard, which would suggest the rod, not the bolts are to blame.

That engine had done maybe 10,000miles on a K03 (circa 200bhp) and then a good few thousand more on the larger turbo (circa 230bhp) lots of trackdays etc. There's a few G40s that claim to make more power but have not suffered rod failures, although I don't know how hard they're driven etc.

What's the spec of the K04, GT2554R is really suited to track, hence my camshaft/turbo choice (268/268 cam) I wouldn't use this for the road much, either a smaller turbo or more mild cam.

Will update this weekend regarding the adapter plate  :)

Cheers

Pete


Offline AdzCM

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Re: Yoof's Turbo
« Reply #347 on: March 14, 2014, 06:06:24 pm »
Thanks for that mate. Really hope mine will be ok. I cant see it being driven too hard. Well not to the extent a track day car would be driven.

I have never seen that before. Was in shock. I saw you had a post somewhere with an engine mock up or something, and saw the block with the hole in it and thought I was seeing things haha. Really unfortunate!

How do you mean the spec of the K04? I'm building a 1341 with the K04, BVH, 51mm TB, port matched GT inlet manifold and 268 cam etc.

I'm using it for a weekend toy really. Not going to use it on a track or drag strip. Would be too scared of wrecking it.

I was going to use a hybrid K03 but a K04 popped up for sale and thought why not. I actually regret buying it because I reckon its going to create nothing but problems for me. Might go back to a K03 after a while.


Cannot wait to see how this adaptor plate turns out. I'm still set on one when you get it sorted. Will definitely need one if I stick with the K04

Sorry to hijack your thread. Cheers for the reply.

Adrian

Offline Yoof

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Re: Yoof's Turbo
« Reply #348 on: March 15, 2014, 08:55:25 am »
Adrian- Regarding the K04, if you've got A/R Ratios, size of compressor and turbine wheels that will give you a good indication of what it can flow, ideally if you can find both the compressor and turbine maps for that trim of turbo you can match them to your spec, if you search Garrett's website they have a fairly comprehensive guide regarding turbo matching. Although it's not quite as clear cut as that.

I'd be tempted to start with a K03, with a larger map sensor and ~21/22psi you'll see 200-210bhp on your spec, which for the road is plenty!

Rod through the block was unfortunate, it also took £600 worth of roller bearing turbo with it! Lesson learnt...  ;D

Adapter plate is in the car and chassis leg is cut, I'll update on Sunday as the thread is a few weeks behind the angle grinder...

Pete

Offline Yoof

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Re: Yoof's Turbo
« Reply #349 on: March 17, 2014, 09:59:00 pm »
Adapter Plate

The last post covered the design of the adapter plate; this post covers the manufacture of it.

The plate starts life as a 10mm thick piece of mild steel sheet roughly 400 x 400mm. The profile is then cut with a water jet, these are a nice alternative to laser cutting in my experience, accuracy is dependent on the machine, but typically ±0.02mm I believe this also depends on the thickness of the part and hardness of the material.

In an earlier post I mentioned the accuracy of clutch alignment had to be <0.1mm, I will cover this later in the post, but remember 0.1mm for now.

So, first job was to get the plate cut out, once profiled it looked something like this:



Fairly uninspiring, and not much use- the holes for the golf mounts have been sized for an M12 tap, hence the different sizes, Polo bolt pattern uses through bolts (bar one) so have clearance holes.

Staring at a drawing, lots of tea, and using the Polo spacer plate helped get things sorted in my head:



In my old unit I used to have a pillar drill, I’ve since moved and had to get rid. This was the perfect excuse for PPP to purchase a drill so I can make these adapter plates; I doubt the profits from adapter plates will ever payback the cost of the drill mind  :D

Drill Time

Axminster with a 16mm chuck (important):



So, first job is to bolt the plate down and start lining things up. (The first job was actually the laborious task of getting the drill perfectly level, bolting it to the concrete floor, greasing it all and rebuilding it after dismantling it to securely mount it, but that’s boring...)



The drill is fitted with a conical shaped bit which allows a true center to be found. This is vital, we can assume the holes have been profiled accurately (±0.02mm) so the biggest inaccuracy comes from me setting the drill correctly.



Once the center has been found (i.e. the headstock isn’t pushed in any direction when engaged with the hole) I then swapped to a 16mm slot drill for the dowels.

I lightly scored the plate and measured the witness marks and convinced myself I’d got everything true:



Time to make some swarf:



So, first hole cut. I wasn’t happy with the drill, upon measuring the hole it was 16.38mm (Dowel OD is 16.0mm) so the dowel was like a dick in a shirt sleeve. The drill was chattering slightly, I decided to reduce the drill speed, use a different oil (0w40 fully synthetic from the other half’s car) and not be such a wimp.

First Hole with dowel:



Not good!

Second hole with revised cutting speed, lubrication and a little more pressure resulted in 16.09mm, result!



Second hole with dowel fitted:



At this point I decided to measure various boxes I had laying around, I expected bang on 16.0mm from each, I was wrong. 16.08mm to 16.23mm- now some of my boxes have been on and off multiple times, but it was encouraging to know I could get the tolerance towards the tighter end of the spectrum. So, my target of <0.1mm from earlier was looking possible. I have no way of measuring this in an installed position, so I can only go from dowel locations.

My tolerance stack is 0.09mm on the two Polo dowel holes, and 0.02mm on the Golf dowel holes. Although I’m using the holes which had been profiled to locate my center find in, so assume I can get a Polo dowel to 0.11mm and a Golf dowel to 0.02mm. So not quite the <0.1mm original target, but without a milling machine I can’t get this any better, plus it’s an improvement over some of my stock gearboxes!

Onwards!

Countersink

The plate bolts to the Polo block, this dictates the face must have countersunk fasteners, I used an A2 grade stainless M12 countersunk bolt. Quick check of the DIN/ISO standard gave me the angle of the countersink bit I needed to order (they’re usually 90° but worth checking).

So big countersink bit arrived, these are known as snail shells apparently, they don’t chatter and I've been really impressed with it, leaves a nice finish and swarf is easily moved.



This process is the same as the slot drill, fit the center find, adjust, clamp the piece down, check, recheck, measure, adjust etc. Then countersink until the bolt fits flush!



All the bolts holes requiring a thread are then tapped- I used the pillar drill to start them all off, ensuring the thread was perfectly square, worked a treat!

Post Machining

Quick clean up and the plate looked like this (both sides shown):





You’ll notice there’s a mark from a grinder- for some reason I’d cocked up the measurement of the crank end oil seal housing. Bit of a pain, but it can be removed for mockup and the design revised before the next iteration.

Few more close ups:





Dry Build

Once I’d done some measuring and checked the plate was straight and true, I then bolted it onto the Polo block. It is necessary to keep the standard plate so the dowel engagement is correct.

Looks something like this:





When bolted up the gearbox starts to look fairly large! You can also see the engine canted over to accommodate the driveshaft and output shaft clearance.

In the next update I’ll go over chassis modifications, cutting big holes out the leg, and hammering a square peg in a round hole. Although it will be fairly boring as it’s me making lots of measurements and swearing. I did get to play with my grinder though.

Cheers
Pete



Offline z3i

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Re: Yoof's Turbo
« Reply #350 on: March 17, 2014, 10:30:34 pm »
Pete this is amazing! such awesome fabrication skills dude! the countersink drill is sick!
really liking this
the only thing that worries me is how far forward the engine is tilted, doesnt look like much room for turbo/charger?

cant wait for more updates!!!

Offline z3i

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Re: Yoof's Turbo
« Reply #351 on: March 17, 2014, 10:31:53 pm »
also yes that box looks massive now its bolted up to ickle polo block. its mad to think that tiny engine produces so much power it needs a gearbox bigger than it

Offline Yoof

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Re: Yoof's Turbo
« Reply #352 on: March 17, 2014, 10:51:24 pm »
Pete this is amazing! such awesome fabrication skills dude! the countersink drill is sick!
really liking this
the only thing that worries me is how far forward the engine is tilted, doesnt look like much room for turbo/charger?

cant wait for more updates!!!


Plenty of room  ;)


Offline Ben.lopo

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Re: Yoof's Turbo
« Reply #353 on: March 18, 2014, 06:20:02 am »
Haha ..... WOW! Looks great I mean the plate adaptor , can't wait to see it go, and everybody would love a 16v g40 but only thos who dear get what they want ;-)  ,
« Last Edit: March 18, 2014, 06:23:29 am by Ben.lopo »

Offline z3i

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Re: Yoof's Turbo
« Reply #354 on: March 18, 2014, 07:08:16 am »
Pete this is amazing! such awesome fabrication skills dude! the countersink drill is sick!
really liking this
the only thing that worries me is how far forward the engine is tilted, doesnt look like much room for turbo/charger?

cant wait for more updates!!!


Plenty of room  ;)



:O :O :O
That is an absolute beast!!!
You have some secret plans yours not telling us? :P

Offline Yoof

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Re: Yoof's Turbo
« Reply #355 on: March 18, 2014, 08:05:53 am »
That's not my car! It belong to Christian from Bavaria, he posted pics a few years back. Worth noting the 02A gearbox (now Sadev) and G60 blower strapped on the front  ;)

Offline Jezza-7

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Re: Yoof's Turbo
« Reply #356 on: March 25, 2014, 04:32:01 pm »
Seen your pics up on facebook the other day, cant wait to see this in action.

When do you reckon it will be completed?

Offline z3i

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Re: Yoof's Turbo
« Reply #357 on: March 25, 2014, 05:14:30 pm »
That's not my car! It belong to Christian from Bavaria, he posted pics a few years back. Worth noting the 02A gearbox (now Sadev) and G60 blower strapped on the front  ;)

And the 16v head :P I don't think I could cut the leg man! How much do you have to cut off?
Would you really cut chassis legs on a genuine G?

Offline Yoof

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Re: Yoof's Turbo
« Reply #358 on: March 26, 2014, 07:59:11 am »
Jezza- Not sure, I'm in no rush (also organising my wedding - or helping to) so don't have much free time.

Taylor- A fair amount, current pics are on PPP facebook page, but I will update this thread in a week or so. On a concourse car and a low mileage minter I wouldn't, on a 'normal' G40, yeah why not, better than keeping the original setup and breaking gearboxes  :)

 

Offline z3i

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Re: Yoof's Turbo
« Reply #359 on: March 26, 2014, 10:40:16 am »
Ah cheers dude, just had a look :) looks good!! That gap is very very tight between the turbo and front panel, my one is rotten anyway so I'd probably get a a pattern one and cut a section out of it for the g60 to fit

I can't really see a great deal of cutting on the chassis legs, any chance of a close up? It does look alot more professional than roettele racing, they just hacked the shit out of it

With an even weaker chassis leg will it need to be reinforced? If I go g60 I will be getting a stage 3 anyway

Mines far from mint, but after all the work I've done it's getting that way. Saying that every single removable panel is from another car haha, and the mileage is 120k

I need a think :( I could talk to you at the show in may, but I hear your "handbrake" is playing up haha
Cheers yoof