GTi-6 - ITBs & CAMMED Track Car.. LATEST VIDEO

[eddy_gti6]

I like it, but it's a bit marmite as it's useless on the road, but brilliant on the track, very noisy, uncomfortable and impractical... But fun!

JP

Comfort and impracticability dont really matter tho when you have another car there you can do your shopping and other bits and bobs in. I wish I had the patients to build a weekend fun car and have a cheap diesel run around for work ect... tried it and didnt work once I got out the hdi into the gti6 I thought f*ck it am using the 6 haha.

what power has it made now the mapping is finished?

[jammapic]

Not 100% sure! I've not seen the dyno plots. Not that bothered tbh, 227hp I think and 200lbft.

[Ben]

Taking this to the ring now then? Driving there or towing with the jag?

[jammapic]

Few cans of man up, and driving it...

[jammapic]

OK... so....

Got the car out of the mates' workshop, finished mapping it (227hp and 200lbft), then promptly MOT'd it and put it back on the ramp again. Lol.

Fitted a set of KSport adjustable coilovers, then stuck it on the Geo machine, setup camber, castor, toe etc before giving it a full corner weighting setup:



Finished fitting my electric PAS setup:



Also fitted solid engine mounts, solid rear beam mounts and sorted a few knocks and rattles from the suspension... then, finally... BROUGHT IT HOME!



We've lived in our new house since October, and this is the first time I've actually parked it on the drive here.

The drive home from the workshop was amazing. Was a little ginger with it at first, given it's been sat for a while... but when I did give it the beans, my god - it's quick.

Corner weighting the car showed up a few weaknesses, like the fact that 66% of the cars weight is at the front, and only 34% is at the back. However, cross axle is next to perfect.

Also, with half a tank of (stale) fuel, and a load of spare parts inside, the car weighs in at 984kg. I reckon without all the spare manifolds, spare wheels etc inside, it would probably be pretty damn close to 960kg.

Got the love back? Hell yeah.

Watch this space!

JP

[ginge191]

Amazing work!!

First in line when this goes up for sale

[Dum-Dum]

Jealous

[7057sam]

Looks awesome

Can't wait for some ring videos

[powerandtorque]

That's pretty light for a 306 given that they're what, 150kg+ up on that as standard? Indeed, I'd say that's probably not far off what a (fully trimmed) 205 GTi-6 weighs in at!

I can't help but wonder if the absolute figures aren't on the optimistic side as ~100lbft/litre would be exceptionally given comparitiverly modest spec? Either way, even assuming they're a few percent high it goes to show what difference paying attention to induction length and some hotter cams makes and that's going to go pretty damned well in a sub-tonne 306, especially with the chassis sorted so that it'll carry that speed through the corners too

Did you do a dummy build to check valve-piston clearance? It's all too often worryingly tight on anything but the mildest of cams on standard GTi-6 pistons as I'm sure you're well aware. Was it the Cat Cam 106's that you went for in the end? 109's would be suicidal on standard pistons IMO but 106's would probably be just about OK providing that the timing is bang on and it's never had a head skim of note.

Anyway, thread has been a good read and I've found the adaptability of the standard ECU to run throttle bodies quite interesting - I'd seen it done with older more basic management before (eg Motronic M3.1) to good effect.

Enjoy the 'Ring - this should be very well suited I reckon

[eddy_gti6]

I am running 3107s on a standard bottom end which if I remember right are the same jamma is using on this engine. There doesnt seem to be much about them on the internet but I do have all the figures somewhere, maybe on my thread but not sure.
227bhp is really good for still running standard injectors, exhaust mani and a cat. Few more £££s should see you into the 230s I would have thought.

[C.A.R.]

Epic. Need to hear the beast now!

I don't like the white alloys

[jammapic]

I think the rollers are a little optimistic to be honest, that said it is a bosch dyno so should be up there with the best. It showed 177hp stock, with just a high flow cat and induction kit... it's probably about 3-5% optimistic I reckon. Even so, it goes well.

I went with the catcams 106's, the head had never been skimmed (until I did it when the headgasket went) so I know it's had 1 skim in it's life. The timing is set 1* retarded from book spec to protect the valves a little....

The white wheels won't be around for too much longer to be honest... I have some anthracite team dynamics in the shed, which will be going on as soon as it gets near a track (they have the new A048r's on).

Question for you... should I be worrying about valve contact at 8000rpm do you think?

JP

[powerandtorque]

I'd be worrying about potential lifter pump-up if you're running sustained 7500rpm+ on hydraulics.

[welshpug]

Retarding by 1 degree isn't particularly an accurate way to do it, you need to confirm lift @ TDC with a dial gauge.

they run 1.25mm on the inlet and 1.05 on the exhaust, the trouble with running them retarded is that the torque will be lower and you'll need to rev it higher to find the peak, which as Anthony said puts you at the risk of lifter pump-up.

Catcams report 17 LBFT on top of the stock 145, given that some similarly cammed 2.2 XU engines haven't broken 200 lbft I highly doubt yours will even be at 170lbft with the retarded cams.

[jammapic]

I can only go off what the dyno says mate. Numbers are just that, numbers... it drives well - that's what matters to me, and there's a bit gain over what it made in stock.

JP

[welshpug]

its not a dyno, its a rolling road.


this is a DYno.

http://youtu.be/JVN7BHjBtAQ

[C.A.R.]

306oc - being pedantic matters :p

[jammapic]

Fair enough

All I know about my setup is that it's stock pistons, with catcams 106's, set just back of book value, despite the head only having had one skim etc.

As of yet, there's been no piston and valve contact... Can it just happen at any time?

JP

[welshpug]

probably any time you're near 7500 or above


any idea how much was skimmed? I hope it was not a mechanical repairs skim


9 thou was taken off mine IIRC, and I have cutouts courtesy of Bridgecraft engineering.

[Dum-Dum]

I'd argue it is a dyno. theres 3 types, its chassis dyno (rolling road), hub dyno (which rules out all the wheel/tyre losses) or engine dyno.

The dictionary (on google) says dynamometer noun an instrument which measures the power output of an engine

so as a rolling road measures engine power output it is a dyno

[welshpug]

It doesnt measure engine power, it measures wheel torque and guesstimates power levels, typically measuring coast down losses as a factor.

[jammapic]

probably any time you're near 7500 or above


any idea how much was skimmed? I hope it was not a mechanical repairs skim


9 thou was taken off mine IIRC, and I have cutouts courtesy of Bridgecraft engineering.

Headgasket was done by CG cars last year - he said the head had never been touched before and it was it's first skim.

I've seen pug1off run these cams in a number of gti6 motors they've built so the cams can't be "too" racey for a stock motor.

Will have to see I guess. Just hope it doesn't let go at the ring!

JP

[welshpug]

Oh feck, i'd be taking those cams out asap then!!

[jammapic]

What is your logic behind that though? They are in, doing what they need to do and they haven't made contact yet? Surely the whole assembly doesn't change lift etc with revs?

JP

[Ruan]

What is your logic behind that though? They are in, doing what they need to do and they haven't made contact yet? Surely the whole assembly doesn't change lift etc with revs?

JP

Unfortunately valves don't always return when you think they will!

Especially on stock valve springs.

[powerandtorque]

At the end of the day, you pays your money and takes your chance.

Certainly I wouldn't be entirely comfortable if it were me running those cams timed up properly on a skimmed by an unknown amount head, especially not knocking on the door of 8k rpm and taking it pretty much unproven over to Germany.

Unskimmed and with the revs below 7500 I'd have reasonable confidence in them being OK.

You should be alright if you're running the cams retarded from Catcams specifications as that will reduce lift @ TDC and thus the chances of the valves and pistons getting intimate, but I would suggest keeping the revs below 7500 as given the clearances you're running any lifter pump up will be terminal. I'm assuming with those cams and a longer inlet that peak power must be lower than that anyway?

The good thing is that you're effectively running a standard engine with some bolt on bits, so worse case is that it's a ~£200 consumable engine and a couple of days to replace it. Bit of a pain if it goes bang in Germany of course...

I'll leave it at this James - all three people I know that have run GTi-6 engine with marginal clearance has at some point down the line suffered a valve related failure. One (Catcam 109's) was on its first trackday after mapping, one (PT81's I think) was about 2-3 months later, and the last (standard cams run advanced) was about a year later, and in each and every case the cam pulleys were still set and the tensioner hadn't slipped.

Perhaps a good (if not particularly valid) comparison would be big turbo'd standard XUD with the fuelling cranked up. It will be fine on its test drive and thus logically it should continue to be fine, but there's a fair chance that it's going to throw a rod at some point - be it a week, a month, or a year.

On the subject of tensioners btw, you are running the earlier 136 tooth belt and eccentric tensioner setup aren't you, rather than the later 137 tooth belt and auto-tensioner? The later really doesn't deal with bigger cams very well and the belt tension tends to be all over the place.

[welshpug]

This had been carefully timed up on PT81's, after a skim by aforementioned garage...






this engine did not tap, but as you can clearly see the valves had been kissing the pistons, there's a ring of wear around each one!!

[jammapic]

Filling me with so much confidence here!!

They aren't as aggressive as the catcams 109's, they are 106's... and I believe they are 1* retarded, however as you say, the head has been skimmed, once.

I'll keep the revs below 7500rpm and cross my fingers.

[Blandy]

Which aforementioned garage did that one?

[jammapic]

I'd like to think it'll be ok to be honest.

The catcams 106 profile only give 1.25mm lift @ TDC, unlike people on Kent PT81's etc which run 1.65mm @ TDC.

Yes, they run a little more total lift, but less at TDC.

Fingers crossed eh?