My E30/R5Turbo track car - Gearbox MkIII

[GeoffBob]

Good luck with the hunt for (genuine!) Garrett parts - does seem a pretty dodgy situation!

What gets my goat is when I phone up the local Garrett agents with Garrett part numbers in hand, and the voice on the other end of the phone tries to convince me not to buy genuine and rather buy one of his knock-offs! I'd e-mail Garrett and tell them if it weren't for the fact that they insist that all correspondence goes through their local agents (who is trying his best not to sell their product because his profit margin on Chinese knock-offs is greater than on genuine parts, grrrrrr )

[GeoffBob]

Been a while since I last posted up a progress report.

I now have a GT3071R on order from Garrett. This is the one that they sell in three pieces (turbine housing, compressor housing and CHRA) shown here

I have opted for the free-floating (non-wastegated) turbine housing with A/R = 0.63.

The primary differences between the GT3071 and my current GT3267 is the slightly smaller turbine on the GT30 (64mm down to 60mm), the slightly larger compressor (67mm to 71mm compressor exducer), and the water-cooled ball-bearing CHRA. The turbine wheel is also made from Inconel and is good for up to 1100'C. That, and the fact that my GT3267 has an integral wastegate that currently renders my boost a little "higher" than I designed for.

The problem with my existing internal wastegate is down to the fact that my engine has demonstrated an unplanned for ability to flow up to 40lbs/minute of air, whereas I only designed for 30lbs/minute. While I am truly in awe of the 3S-GTE's ability to flow more air than I believed possible, it has left me in the uncomfortable position of having to bypass every extra lb/sec of mass air flow above roughly 17lbs/sec through a dinky sized internal wastegate that was only ever spec'd to flow 12lbs/minute at choke! Boost creep has thus crept in.

As you can well imagine, I am now in the process of modifying my exhaust manifold in order to fit a 50mm external wastegate. Shown below is a pic of the mocked up additional pipes needed to connect the entrance to the twin-entry turbine to the single wastegate. The outlet from the wastegate will be directed out the side of the car (through a ventilation hole in rear of the front left wing), commonly termed a "screamer pipe" for obvious reasons.

[Mikey_Boy]

As always Geoff, well thought out and the final installation is going to be awesome by the looks of the pics. I hope you will be pleasantly surprised by the results, performance feel on tip in will be fantastic and tip out will also improve a lot, helping you manage all that excess boost that needs to be got rid of in a hurry!

[GeoffBob]

As always Geoff, well thought out and the final installation is going to be awesome by the looks of the pics. I hope you will be pleasantly surprised by the results, performance feel on tip in will be fantastic and tip out will also improve a lot, helping you manage all that excess boost that needs to be got rid of in a hurry!

Thanks Mike,

I concur with your comments with regards to tip-in and tip-out.

I have installed an audible alarm to alert me as to when "tip-in" occurs - one that I should be able to hear over the whine of the gearbox .

[Mikey_Boy]

Surprised you need any alarms Geoff!

I would have thought the huge push in the back and having to hang on for dear life would be warning enough..??!!??

As another thought - have you considered coating the exhaust manifold to keep more heat in the primaries before the gas hits the turbine? You have spec'd a fabulous turbo that will more than take a bit of extra heat input... We mapped for 950 degrees turbo in during my Cosworth days - a well placed K Type will help you quite a bit here!

I am considering having my BTB manifold coated to help a touch and manage the heat...



Cheers,
Mike

[GeoffBob]

I would have thought the huge push in the back and having to hang on for dear life would be warning enough..??!!??

With my level of driver skill that's what I don't need! I prefer my torque pedal rather than RPM dependent. I find the sudden onset of torque with boost quite disconcerting, which is why I implemented an electronic boost controller to hold-off on the onset of boost. The idea works (it's well documented in all the books as working so hardly needs a nod from me, even my Megane RS has the boost under electronic control) but requires a soft spring in the wastegate actuator.

As another thought - have you considered coating the exhaust manifold to keep more heat in the primaries before the gas hits the turbine? You have spec'd a fabulous turbo that will more than take a bit of extra heat input... We mapped for 950 degrees turbo in during my Cosworth days - a well placed K Type will help you quite a bit here!

You are quite right Mike, I should. I was simply going to wrap it in heat tape when done, but ceramic coating would be so much better. Not so much to keep the bay cooler, but to keep the gas temperature entering the turbine higher, which is why I wanted an Inconel wheel this time around that could take the heat. When I started building my car I established that the GT3071 was ideally what I needed on my engine, but I couldn't afford one at the time with all the other bits I had to buy, so I settled for a GT3267 which is the closest to the GT3071 at a fraction of the cost. When I ran into problems on the dyno the other day I could hear the GT3071 calling my name again, and so I have made it my Christmas present to myself this year. The wife gets a box of milktray (again).

I have a box of K-type thermocouples in my storeroom, I will be sure to fit one. I would also like to measure the pressure at the turbine inlet, but am put off by the idea of having to install 4ft of steel tube between the sensor and the manifold to sustain a safe heat gradient (stopping me from reducing the sensor to molten plastic, again).

[GeoffBob]

I have finally finished modifying the tubular manifold and the external wastegate is installed.



I now have this sticking out the side of my car And before anyone asks, the pipe isn't anywhere near the tyre.



I have drilled and tapped an M10 bolt into the back of the GT32 turbine housing in order to lock down the small internal wastegate. This will do me for the time being until the GT3071 arrives mid-to-end January. 'Should have the GT3267 reassembled and re-fitted over the weekend. I am anxious to get the car back down the track for futher testing, or at least to get the surface rust wiped off the discs. This is the longest my car has stood in a while and I am not happy about it.

[gareth]

cleaning the discs, sounds like the perfect excuse for a good thrashing

That's going to be a hilarious way of scaring people as you overtake! PISSSSSSH!

[GeoffBob]

cleaning the discs, sounds like the perfect excuse for a good thrashing

I can’t wait TBH! I’d like to be back down the track this coming Wednesday, but with Christmas approaching and family commitments looming I might have to reconsider.

That's going to be a hilarious way of scaring people as you overtake! PISSSSSSH!

I have my concerns. I have two free-flow mufflers tucked up under the back of the car (either side of the diff, above the side-shafts) and I am wondering what for? When that wastegate opens all hell is going to break loose. More akin to a fleet of mad chainsaws than a PISSSSH. To balance things out I fancy losing the mufflers at the rear and simply emerging the tail-pipes just in font of each of the rear wheels (one left and one right). To hell with noise concerns, she’s well and truly a track-car now and I can always wear ear-plugs. At least then I won’t have to listen to that infernal whine from the gear-box.

Goodness, this is fun. I can’t wait to hear what she sounds like

[billgatese30]

To balance things out I fancy losing the mufflers at the rear and simply emerging the tail-pipes just in font of each of the rear wheels (one left and one right). To hell with noise concerns, she’s well and truly a track-car now and I can always wear ear-plugs. At least then I won’t have to listen to that infernal whine from the gear-box.

Goodness, this is fun. I can’t wait to hear what she sounds like

That just has to be done Geoff, it would be rude not to now that you have the screamer pipe.

The wastegate fitment looks excellent as usual.

[Mikey_Boy]

+1

Excellent job as always Geoff - looks great! You might be surprised at how (ahem) refined it could be - I think it's going to sound awesome!! You have a diffuser on it and that always helps with the relative noise... you might be painting the panel immediately behind the wastegate pipe though - that might get a touch toasty!

I think you might be getting pestered for 'drive by' videos soon as well!

I take it you have no issues with noise restrictions in your part of the world??

Look forward to the updates!

Cheers,
Mike

[GeoffBob]

As always, thanks everyone for the comments.

The wastegate fitment looks excellent as usual.

Excellent job as always Geoff

Thanks Chris & Mike!

You have a diffuser on it and that always helps with the relative noise... you might be painting the panel immediately behind the wastegate pipe though - that might get a touch toasty!

Diffuser? Oh, you mean the bit of drainpipe I stuck on the end
Hopefully I won't need to repaint anything Mike. That pipe sticks out a fair way specifically to avoid that problem. But if push comes to shove, I have a piece of aluminium plate ready to rivet in place.

I take it you have no issues with noise restrictions in your part of the world??

At the track, no. On the roads, yes, but little or no enforcement.

The GT3267 is now back in the engine bay. Sadly I won't be firing her up today as I see I have stupidly left the wasetgate gaskets on my bench at work. I also need to pick up a few copper washers for around the banjo-bolt oil feed to the turbo. I don't fancy it leaking again. I'll pick these few bits up tomorrow morning and then see if I can't make it back down the track on Wednesday (that's if it’s open and it isn’t p!ssing down). I’ll take a video camera along again ”“ this time I’ll try and get the sound to work.

EDIT: Bugger! I just checked the Zwartkops online calendar and they are closed until the 5th of January

[Mikey_Boy]

No noise restrictions at the track???!!?? Oh my - you are lucky!!

It's getting worse and worse on the UK - thankfully there are still a few 105 dB trackdays left though 95 - 99 dB seems to be the norm.

My BTB exhaust on my 325 is great though - registers 85 dB to make it future proof!!

Hopefully you won't need to re-paint anything - never ceases to surprise me how toasty things around exhausts get - I melted a clutch reservoir drifting (which has since been relocated) and another reason to get my manifold ceramic coated... I remember recording 550 degrees C gas temp out of the tailpipe of a Ford V6 at VMax whilst hot climate testing...

Disappointing that you can't get your beastie out on track before the New Year - maybe a chance for you to relax and reflect on a great car building and development year for you...!

Look forward to the vids!

[e301988325i]

That's going to be a hilarious way of scaring people as you overtake! PISSSSSSH!

Gareth, I think your mistaking the screamer pipe for a dump valve.

When the wastegate opens, unsilenced exhaust gas will be exiting, and I can asssure you it will make our cars sound like electric hybrids.

[GeoffBob]

No time for relaxing Mike. Too many niggly things to finish off on the car, always will be.

For example, fitting the external wastegate has necessitated discarding the oil catch-tank that I only recently fitted. Simply no room for it on that side of the engine with the wastegate added in. While it was tempting to make a plan (possibly cut it in half and slide it up a bit, I didn't fancy the hazard of having an oil catch-tank located up against the wastegate. And so I built a new one.

The old (but still quite new ) one is on the right, and used to locate on the outside of the passenger footwell/firewall where the wastegate now sits.



The new one (which looks rather like the head off a robot) custom fits into the only remaining space on the driver side of the engine bay. If the robot's head looks out of square it's because it is. It's roughly trapezoidal in shape (viewed from above) so as to fit into its little spot like a hand in a glove. I should have done it this way in the first place TBH since the breather hoses run more naturally to a tank on the drivers side than they do the other way.



Other things still to do will be to fit the new turbocharger when it arrives, not too mention that I still haven't assembled my 4.1:1 final-drive with the Quaife differential.

Never a dull moment with this car.

[gareth]

That's going to be a hilarious way of scaring people as you overtake! PISSSSSSH!

Gareth, I think your mistaking the screamer pipe for a dump valve.

When the wastegate opens, unsilenced exhaust gas will be exiting, and I can asssure you it will make our cars sound like electric hybrids.

I am not mistaken That's just my best keyboard effort at the sound of a screamer pipe

For reference, a dump valve is PISSssh

[GeoffBob]

[kerrie]

Baie Mooi Boet!, Excellent work Geoff, What are the 4agze motor going for in SA at the moment, thinking of puting one in a E30 and turbocharging it.
Cheers

[n1tr0_9]

How about a duck call?

[GeoffBob]

How about a duck call?

Very amusing! Has got me thinking, all sorts of things one could attach. What about those party things that shoot out and make a squeaky noise when you blow them?

I wonder if I could get a vuvuzela to work?

Baie Mooi Boet!, Excellent work Geoff, What are the 4agze motor going for in SA at the moment, thinking of puting one in a E30 and turbocharging it.
Cheers

Dankie Kerrie. Lyk soos ons plekke omgeruil het? Ek is oorspronklik Tunbridge Wells uit.

A Jap import 4age must be around the kR5 to kR8 mark I would think? The gze has to be at least kR2 more with the SC12 supercharger attached. Do you want to add the turbo to the SC12 to make it sequential, or to simply turbocharge a 4AGE?

[kerrie]

Yes, Originally Pietermaritzburg.

I would want to take off the SC12 and install a Garret ball bearing turbo, They make some huge power in standard form, I believe they will take 1.2 Bar boost in standard form, and are strong as nails! and the exhaust comes out on the correct side for a turbo application and steering shaft space!
Your build thread is great, good work!
Cheers

[GeoffBob]

Not meaning to rub it in (I know you lot up north have had it hard this season) but the weather down here has been absolutely gorgeous the past week! And what with the local track being closed for the holiday, I couldn't resist taking the car out for two quick spins around the quiet end of the neighbourhood in order to test the recent modifications. Not having any prior experience with the new wastegate (my first external ever) I adjusted the pre-tension on the spring to the minimum (I wound the bolt out) and disconnected the electronic boost controller, in order to achieve the minimum boost pressure possible (defined purely by the tension in the spring). In this way I observed a solid 0.5 bar of boost from roughly 3500 rpm all the way to the redline, with no sign of the old boost creep. I am very happy, to say the least. The screamer pipe is audible, but only just over the noise of the gearbox. TBH, it's not as aggressive as I expected, although admittedly, I am inside a closed cockpit (the windows don't open). The combined sound of the exhaust and the gearbox is reminiscent of a rally car, which is to be expected. I will see about reinstating the electronic boost controller now that I have established a base-line value of 0.5bar.

I will be spending my holiday finishing off umpteen niggly things on the car and return to Zwartkops first Wednesday of the New Year to ”aproperly”a evaluate my cars progress. If she behaves herself I might buy her another hour or two on the dyno.

[GeoffBob]

Finished quite a few of those niggly jobs during my leave from work. Amongst others, I finally got around to fitting the mandatory emergency pull-handle adjacent to the transmission tunnel. This, along with one on the outside of the car, connect to the heavy-duty kill-switch mounted next to the battery-box in the rear of the car.



I pulled apart an old camera tripod in order to build my own camera mount. I bent up a bracket from aluminium plate which I welded to the tripod centre-column, which I then bolted to the front of the battery box. Neat. Now all I need is my own camera.



I thought I would also take the opportunity to repair some cracked paintwork on the drivers door (brought about when I manhandled the door during fitting), a small job that required that I remove the 4mm polycarbonate window. Having nowhere immediately to hand, I put the window down on the bonnet of the wife’s car while I disassembled the rest of the door. The wife then went shopping and that was the last I saw of my window. Fortunately I had just enough polycarbonate left to make a new one. I can’t help wondering where my old window is though. Anyone seen it per chance? Knowing my luck the wind caught it and it nailed an innocent pedestrian between the eyes, not that the wife would have noticed.

[Jon_Bmw]

You sick man, a wooden gearknob! What an executive.

[UweM3]

sorry but had a good old chuckle about the window story. LooooL!

[Mikey_Boy]

+1

Brilliant! The window story bought a smile to my face!!

It's all coming together nicely Geoff - keep up the good work!!

[GeoffBob]

You sick man, a wooden gearknob! What an executive.

Yeh, right There's a story behind that knob. I picked it up at a flea market about ten years ago. It's off some or other vintage Renault. It has the really old (circa 1950) Renault logo on top. It just seemed appropriate to use it again.

sorry but had a good old chuckle about the window story. LooooL!

I was angry at both the wife and myself at the time. Now I can see the funny side of it . That'll be the last time I put anything down on the bonnet of the wife's car, I've learned my lesson!

+1

Brilliant! The window story bought a smile to my face!!

It's all coming together nicely Geoff - keep up the good work!!

Ta, thanks Mike.

[GeoffBob]

Well, as promised I was back at the track yesterday. I had the car on the dyno in the morning to confirm the operation of the external wastegate. The night before I plumbed in a small dash mounted pressure regulator in order to apply a fixed pressure to the rear of the wastegate diaphragm. The old electronic boost controller (the ECU) worked fine, but I could only ever adjust it via the laptop. With this I have dial-a-boost mounted on the dash. Shown below is a pic of the manifold still glowing red, taken while the manifold was cooling down. The whole manifold lights up while the engine is under load on the dyno, but I am too cautious (sane?) to approach the car while the rollers are spinning. Braam (the dyno operator) related a horror story to me where a customer had accidentally put a foot on the rollers, been pulled under the wheels and spat out the back. One can never be too cautious around two 2-ton rollers!



Braam set the boost (via the pressure regulator) to 0.9bar, at which point the car was making just over 200kW at 4500rpm, peaking at 240kW at 5800rpm, measured at the wheels. I am not even interested in the flywheel power anymore since the software clearly cannot estimate my gearbox losses.

Back on the track it was evident that I was wearing the clutch out at a rate of knots and that I will have to upgrade. Punching the throttle after the final 90' turn into the pit straight brings about massive clutch slip (provided the tyres have warmed up). The difference in pedal travel after the first session was quite noticeable (not a fluid issue since the clutch hydraulics are all on the cold side of the engine) I plan to fit a button clutch when I next have the engine out, which will be soon since I lost 3rd gear on the gearbox during the penultimate lap of the 2nd afternoon session. I don't think the box is damaged (there was no crunching of gears) so I suspect a linkage problem. I see it as all part of my R&D strategy. I will eventually iron out all weaknesses in the box. It was inevitable (imo) that the first iteration of my design would not last very long. I am VERY keen to open up the box and see how the gears (and particularly the dog teeth) are wearing.

Oh, and before I forget, the video camera worked fine this time. Once I've figured out how to transfer it to my PC I'll post up some footage.

[Mikey_Boy]

Excellent stuff Geoff! 240kW equates to about 312hp at the wheels which is fantastic, which and that suggests about 368hp at the flywheel using a very large rule of thumb!

Looking at your manifold, getting it ceramic coated will only help you from a thermal protection and turbo response point of view...

Agree entirely about being careful around dynos! I have a few stories of folks being in dyno cells and near misses from various engine parts flying past their heads...

I think your dog teeth will be just fine - having your clutch as the weakest link in the chain is a really good idea - cheap and easy to replace or upgrade to the point where it JUST survives a good thrashing on track and then acts as a (safe) warning to come in and let everything cool down for a bit (including the driver!!!)

Can't wait for the video footage!!

[appletree]

Great progress Geoff, can't wait to see and hear it!

Just know its going to be mental!

[billgatese30]

Come on Geoff, I'm in the US next week and won't be able to view the video unless you figure it out quickly

[GeoffBob]

Excellent stuff Geoff! 240kW equates to about 312hp at the wheels which is fantastic, which suggests about 368hp at the flywheel using a very large rule of thumb!

Thanks Mike. As you may recall she did just over 350hp at the wheels last time, but that was at around 1.1bar of boost. Beyond 5500rpm she started to detonate so Braam opted to pull the boost down to 0.9bar, which no longer creeps upwards with the external wastegate fitted. Personally I’d feel more comfortable with the minimum 0.5bar of boost, but then the car certainly wouldn’t be as fast as it is at the moment. I can always opt to raise the boost pressure later provided I switch over to race fuel ”“ she is currently running on 95RON.

Looking at your manifold, getting it ceramic coated will only help you from a thermal protection and turbo response point of view...

All in good time Mike. First I had to ascertain that the external wastegate was working and that all my welds would hold together. No point in ceramic coating a manifold that has to be rebuilt.

Come on Geoff, I'm in the US next week and won't be able to view the video unless you figure it out quickly

Sorry Chris, but the video won't be posted until early next week. I need to install a video interface card on my home PC so that I can transfer the video across. The camera I borrowed has a USB port, but the software has gone AWOL, so I have no choice but to use the old audio/video method. To wet your appetite, however, the camera has a built in memory-card, to which I was able to transfer some stills from the video.

Great progress Geoff, can't wait to see and hear it!

Just know its going to be mental!

Matt, the video is indeed mental. I've watched it on the camera LCD and it makes for interesting viewing. I have two high-bright blue LED's either side of the tachometer wired to the Adpatonic ECU. These function as my shift lights and are set to light up at 6000rpm, you'll see these come on in the video, after which I shift up and the engine speed drops to 5000rpm. This was my first sign that the gearbox is doing what it was designed to do. Zwartkop's has relatively short straights with little opportunity to build speed, so acceleration is of utmost importance and you must keep your engine speed up if you want to overtake. You won't see much overtaking on the video though as there were only four or five of us out on the track that afternoon.

Some other news is that something glinted in my headlights as I was driving home from work last night, I instantly recognised it's shape as my missing window. I was quite surprised how well it survived laying on the side of the road. So now I have two. I think I'll drill holes in one and make it my "summer" window .

[billgatese30]

Some other news is that something glinted in my headlights as I was driving home from work last night, I instantly recognised it's shape as my missing window. I was quite surprised how well it survived laying on the side of the road. So now I have two. I think I'll drill holes in one and make it my "summer" window .

Ha! Thats even better than the story about how you lost it in the first place!

Don't worry about the video, it will give me somthing to look forward to upon my return.

[GeoffBob]

Took me a while to figure out how to transfer video to my PC. Had to pop out and buy a nifty little USB video interface as my old PCI card had packed in (couldn't get the drivers to load no matter how many times I tried). I then had to figure out how to reduce the resolution and then upload to YouTube, but with all that done, here it finally is, enjoy:

[youtube][/youtube]

[Theo]

Mega!

Sounds like the old BTCC Sierra Cosworths, other than the rubbing wheel arch noise! Blame that on the heavy passenger...

I love it.