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Lupo GTI Rally car project


imaparana
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Update:

Some engine mods have been on the cards for a while now, with the jersey rally (main event of the year) being cancelled due to Covid now has been the ideal time to start this.

In the hunt for more power, i decided to bite the bullet and go standalone ECU as no one on island can map the factory ecu. Aswell as doing an AVY/AFH Hybrid built (very basic)

I managed to pick up a 6n polo 16v for a donor head (AFH) which would form the base of the upgrade.

3096715-D-0322-450-B-9-FAB-C3-FA9-DB0-DE 

7-E1-C3667-4-CF1-4124-AE60-0-B8816257-A8

I rebuilt the head which was pretty minging for a 40k miles car, and stuck it on the stock bottom end. And ran it on the stock management in order to bed the cams in.

DF69-ACED-01-A2-451-B-A1-D9-0-E020-B7284

9-CBF3324-754-D-48-B5-967-B-F5-A72370-D4

Once all was bedded in i started on the Standalone conversion

I went for a ME221 motorsport electronic ecu which has alot of features of expensive ecu's for a lower price point. I then spent a good few days making an engine harness for it. Keeping the stock ecu to run the clocks (minus the rev gauge)

E3258-DF5-29-C7-4-ABB-8-C82-C6-F4-F13-FC

With the new ecu wired up it was a case of putting it all together, injection is by the way of gsxr600 itb's on a danst intake manifold.

F1584-C1-C-293-B-4521-A4-AD-567787-ECBA7

with a few tweeks to the basemap it fires up and idles sweet, with the lovely itb soundtrack. Also fitted in a aem wideband gauge to get the idle safe before the dyno session, aswell as an oil pressure light on a higher pressure switch. this had to be wired up separately to the factory light as having the engine run on the standalone, the factory ecu doesnt like to see oil pressure when it thinks its not running.

59096-AC4-1-BB5-4278-AB5-E-08171662148-E

The rolling road day is in 2 weeks time, a week before the next event so fingers crossed for no dyno day hickups

Edited by imaparana
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3 hours ago, LR5V said:

Nice work - how did you choose trumpet length or did Danst advise?

I missed all the brake chat before - I can see the ABS is away, are you now on a pedal box with master cylinders front and rear?

Last Q - what's that caged shell lurking under the loom table?

I went for the biggest i could get really, Danst said they fitted 50mm on a lupo before, the other option from them was 90mm, i went with 75mm from somewhere else and just waiting on a pipercross filter to go over them.

Yup abs is gone, running the stock pedal box which needed abit of fettling to fit the cable pedal. i have a bias valve in the line to the rear brakes

Its a friends subaru GC8, ive been in his garage while faffing around with wiring

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Dyno day went well, minor hickups with the throttle cable/linkage which needs sorting before the next event, aswell as some venting to the ITBS as the intake temps were skyhigh 35+throughout the run.

Despite this it made a healthy 163.9 bhp & 134ftlbs of torque, Torque has moved up the rev range from the VVT setup before which is to be expected. More is likely to be gained from an aftermarket manifold but will keep the stock one for now.

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9 hours ago, LR5V said:

Good solid result - how high have you made you rev limit? - mine just wanted to keep going past 7K, no sign of power drop off till very rude hard limit at 7.6

 

its got a soft cut around 7650, peak power is just after 7k :) 

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That is really screaming. What sort of ignition advance is there at 7k? And how early do you start injection? And you must be using huge injectors to have enough time to inject enough fuel at those revs? And how's it idle? Lots of Q's...!

Nice 👍🏻

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2 minutes ago, mk2 said:

That is really screaming. What sort of ignition advance is there at 7k? And how early do you start injection? And you must be using huge injectors to have enough time to inject enough fuel at those revs? And how's it idle? Lots of Q's...!

Nice 👍🏻

ill have a look at the map and get back to you on the complex questions, 

Injectors are the stock gsxr600 ones which i think are 240cc, but are at 80% duty so any more power and would probably need some bigger ones

idle isnt too bad now ive balanced the itb's, its been raised to 1000 ish as itd try and die when the fan comes on or i turn the wheel at idle which loads the engine

ill post a picture of the graph when i get a chance

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You must be running like half a millisecond pulses at idle. Or higher fuel rails pressure? I love this stuff! Great!

Hey, I just thought, have you considered upping the compression ratio (deep head skim- like a couple of mm)?

late edit: misread your post. Stock injectors means probably 1.5ms...

Edited by mk2
I don't read.
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1 hour ago, mk2 said:

You must be running like half a millisecond pulses at idle. Or higher fuel rails pressure? I love this stuff! Great!

Hey, I just thought, have you considered upping the compression ratio (deep head skim- like a couple of mm)?

late edit: misread your post. Stock injectors means probably 1.5ms...

I had thought about getting it skimmed and ported while it was off the polo but nowhere locally really does that sort of stuff

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  • 2 weeks later...

Quick pre event update, Ive been having some starter motor grinding issues which havnt been solved with swapping the starter, however the car has always started... until tuesday night...

Starter motor stopped engaging with the ring gear, swapped starters again only to find the issue wasnt fixed.

Was a late one pulling the box out tuesday night to find the teeth on the lightened flywheel were absolutely goosed! aswell as signed of uneven wear on the friction disc against the flywheel also.

the clutch never felt the same after fitting the lightened flywheel so i suspect it was either the wrong part or just badly designed.

Got the stock one back on now for tomorrow's event and it starts super quietly now.

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On 9/25/2020 at 9:43 PM, LR5V said:

not what you need just before an event - Good luck

where did you get the flywheel?

 

It’s an epytec one, I know quite a few gti’s run them so maybe a one off problem or something, not spoken to them yet as not sure I want to put another on to have a similar issue

Had a great event on Saturday finishing 1st in class and 6th overall (out of 9 entrants). The new power definately made a big different on the longer sections and uphill areas.

areas that need addressing before the next event:

oil leak to fix

leaking oil filled engine mount to fix

gearbox oil leak to fix

maybe fit an updated clutch and it was abit smelly at times

 

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1 hour ago, imaparana said:

It’s an epytec one, I know quite a few gti’s run them so maybe a one off problem or something, not spoken to them yet as not sure I want to put another on to have a similar issue

 

That's not a cheap part - TBF the others are probably not ran as hard as you are! 

I would suggest getting an OEM one lightened  - my guy in South Wales knows what he is doing, tell him what you want and he will lighten it down keeping strength and balance

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8 hours ago, LR5V said:

That's not a cheap part - TBF the others are probably not ran as hard as you are! 

I would suggest getting an OEM one lightened  - my guy in South Wales knows what he is doing, tell him what you want and he will lighten it down keeping strength and balance

yea good idea, i had thought of that but didnt know if itd been done before (if the gti one was hollow or anything like that) , will have a look into it over winter :) 

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On 9/28/2020 at 9:28 PM, imaparana said:

It’s an epytec one, I know quite a few gti’s run them so maybe a one off problem or something, not spoken to them yet as not sure I want to put another on to have a similar issue

Had a great event on Saturday finishing 1st in class and 6th overall (out of 9 entrants). The new power definately made a big different on the longer sections and uphill areas.

areas that need addressing before the next event:

oil leak to fix

leaking oil filled engine mount to fix

gearbox oil leak to fix

maybe fit an updated clutch and it was abit smelly at times

 

Interesting that the Epytec flywheel decided to pack up, i've had mine on for about 3 years now and it's been great.

 

Have you thought about filling the standard oil filled mount with poly-resin? I done that to mine and it made a world of difference to engine stiffness!

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3 hours ago, CLAYTONJONES said:

Interesting that the Epytec flywheel decided to pack up, i've had mine on for about 3 years now and it's been great.

 

Have you thought about filling the standard oil filled mount with poly-resin? I done that to mine and it made a world of difference to engine stiffness!

Thanks for the reply, I measured up the flywheel last night and it appears the friction face on the flywheel is only 215mm, the gti clutch is 220mm, I looked on your thread and yours seems different to me (your friction surface is bigger) doesn’t explain the ring gear issue but they may have sent a different flywheel

 

I’d filled a mount with poly resin before and it failed, the rubber on it was pretty worn and cracked tbh which probaly doesn’t help, may try it again, but gets expensive when it breaks shafts and potentially gets me out of the rally in the process

2E4B9716-A29B-483C-917F-C18DC0FA88DE.jpeg

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I've been reading up flywheel theory.... I used to lighten flywheels and after much experimentation, I could never prove if there was a benefit. It's one of those things that is really difficult to measure. Seat of your pants measuring never ever works.

Have you ever had the chance to do a flywheel swap on the same day, then run laps in the exact same conditions; Temperature/ambient pressure/humidity/wind?

Also just had a thought about you snapping drive shafts- have you looked at changing the clutch running springs? There's needs to some 'give' in the torsional system. The rotational mass of the engine simply dumped instantly into the road means something has to take that 'snap' or 'twang' as I call it. The torque has to build up slowly- it's the torque shock that breaks things.

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A bad thought just jumped into my head - I hope i'm wrong - have you checked for thrust bearing play in the crank?

To keep the weight down, Epytec may have made the width of the ring gear as narrow as possible, to only suit normal crank end float - if you have wear your crank may be moving out of contact with the starter, OEM probably has wider ring gear keeping the starter in range.

 

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Thrust bearing wear is rare. I doubt the crank has worn. It'd have to move a lot for the starter gear to not fully engage. Like 5mm maybe?

It'd mess up the cam belt too.

Nah, after much deliberation, not end float. 

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Cheers for all the Ideas,

After looking into it and pictures from the suppliers website i think i may have been sent the wrong flywheel or there has been a machining mistake, i'm in talks with them now so hopefully can sort something out

On 10/3/2020 at 9:19 AM, mk2 said:

I've been reading up flywheel theory.... I used to lighten flywheels and after much experimentation, I could never prove if there was a benefit. It's one of those things that is really difficult to measure. Seat of your pants measuring never ever works.

Have you ever had the chance to do a flywheel swap on the same day, then run laps in the exact same conditions; Temperature/ambient pressure/humidity/wind?

Also just had a thought about you snapping drive shafts- have you looked at changing the clutch running springs? There's needs to some 'give' in the torsional system. The rotational mass of the engine simply dumped instantly into the road means something has to take that 'snap' or 'twang' as I call it. The torque has to build up slowly- it's the torque shock that breaks things.

I think my post about the shaft was maybe abit misleading, when the engine mount broke, the engine moved back towards the bulkhead and then broke an inner CV (i havnt pulled it apart yet to work out exactly what failed). The clutch im running is the stock one with a sprung hub. If the box comes out again i think ill put it a  helix sprung 4 paddle, but keeping the sprung hub.

 

Over the weekend i had time to fix an oil leak from the distributor blanking off plate on the head.

I also had the 6th gear side cover off of the gearbox as it had started leaking.

All sealed up and ready for the next one :) 

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  • 2 weeks later...

Flywheel update: Epytec have been great in dealing with the above issue and have just dispatched a replacement fywheel for me, so pressume they sent the wrong one by mistake initially. A helix friction disk is likely to be mounted to it over winter/offseason now there are no more events.

 

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  • 1 year later...

Long overdue update!

I sang the praises of epytec too soon! i got a new flywheel down which was still incorrectly machined. the friction surface was too small for the gti 220mm clutch. So if anyone ordered one be prepared to have it machined down. 

A few updates have happened since the last update:

  • A new ebay afh manifold was fitted, as expected this too a fair bit of bending the clear the gti sump. This gave a few ft/lbs in the mid range of increase over the stock item
  • I 3d printed a Carbon fibre Nylon inlet manifold for the ITBS, the alloy one purchased didnt have very smooth gas flow and pretty poor port matching. 3d printing one enabled me to port match it perfectly. Along with this i 3d printed some trumpets. This along gave a massive increase in power and torque. dyno runs showed a consistent 170-172bhp. This is for all intensive purposes a 10bhp upgrade from the manifold and trumpets alone. A very worthwhile exercise
  • I dropped the 6 speed out to refresh it with new bearings and fitted a 4.53 final drive, at the same time fitted a helix sprung paddle clutch. the final drive made a nice difference, in hindsight a 5.08 final drive would be better for my application but is a fair chunk of change. For anyone wandering the helix clutch is still very driveable!

SInce the last update we have done a few rallies down in the quarry. Car ran flawlessly for all events!

We entered the 2021 L'etacq attack rally, coming 1st in class out of 5 and beat some very quick cars.

The 2021 Jersey rally came around very quickly (8th & 9th) and although the car was thoroughly prepared we had multiple issues all weekend

The first came on SS4, we were battling for 1st in class when we bent a lower arm which lost us a lot of him. this wasnt from hitting anything and we due to the amount of grip the tyres had on an off camber hairpin right. We were gutted as this pushed us right down the standings. This for swapped out at service and started the push to make up the lost time.

The night stages came around and an electrical issue left us stranded on the side of a road section, luckily we managed to fix it with a pair of snips and duct tape! 

The Saturday went great until the penultimate stage (25 out of 26) where we sheared the stub on the RHS cv joint, this put us out of the rally as we lost all drive. upon inspection the cv joint fitted wasnt a JR cv joint, maybe this is why...

Lessons learnt/to do:

  • Lightly reinforce lower arms and dont buy cheap arms. there are reinforcement plates available for mk2 golf arms, ill do a similar exercise. however i don't want to make the arms so strong that the chassis is now the weak point
  • Only use quality cv joints, a lad on the polo forums upgraded to r32 cv joints however this requires a full custom front suspension set up which is abit out of my skill set. Ill just use quality CV's from now on and inspect them once a year

 

Here's some photos of whats happened since the last update (in no order)

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h7w298.jpg

hu7DLN.jpg

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