Astor XS XU7J4RS (For Sale £1000)

[Niall]

The amount of meat I took off the inlets on mine was unreal and I didn't go too mad. Could of taken much more off! Find my XS project threat and look through my rebuild photos in there.

[C.A.R.]

There was a "rumour" and I state that it was a rumour as there was nothing to back it up, on the GTi6 forum some years back, that the XU7 alloy head was found to be superior and the inlet ports were deliberately restricted to make the car slot below the XU10 XSi engine rated at 136bhp (if memory serves me). This was either to make the XSi marketable or lower the insurance groups on the 1.8 models (more likely I think).

[Niall]

There was a "rumour" and I state that it was a rumour as there was nothing to back it up, on the GTi6 forum some years back, that the XU7 alloy head was found to be superior and the inlet ports were deliberately restricted to make the car slot below the XU10 XSi engine rated at 136bhp (if memory serves me). This was either to make the XSi marketable or lower the insurance groups on the 1.8 models (more likely I think).

That really wouldn't supprise me. I can't see any other reason why they would of been so restricted

[Grant]

Grant,

You're beginning to get on my tits now.

Facts:
RS manifold fits onto 1.8
Improves throttle response
Causes flat spots

Unknowns:
Gives a definite performance gain / More power
Overfuels / Underfuels

We don't know whether the flat spots experienced are caused by over or under fuelling, running rich or lean. My car definitely used more fuel which would suggest it over-fuelled, but we don't know whether that accounts for the entire rev-range, without seeing an AFR graph print-out - something nobody has been able to obtain yet.

If you're happy with it then that's good, we're happy for you son. But unfortunately time and time again this manifold swap has incurred 'similar' problems for the majority of end users who carry the modification out.

The above two quotes do not 'contradict' one another. If you re-read more carefully I state that the larger TB imrpoves throttle response, for obvious reasons that anyone - engineering background or not - could understand. However after returning to the standard, plastic intake manifold as found on the 1.8 and 2.0 XSi the 'overall' (crucial word) performance was imrpoved. This is probably because the AFRs were matched better with the parameters which the ECU values are programmed to, so better power and torque could be felt by nothing more than your very own "bum dyno" from the driving seat. Economy improved also, but it was still dire because the aerodynamic characteristics of the cabriolet model are somewhat crap in comparison to a hatch.

Being overly critical isn't the same as having a discussion. I'm keen to know how you have made your conversion work, as you seemingly haven't used any different components to the rest of us. It could be that your ECU is a different model perhaps (I thought the Sagem unit was standard), or that a sensor reading is out. Of course it could be what I suggested earlier in that you might not have noticed where these flat spots lie as yet, depending on how much you use the car.

I'm no engineer and don't pretend to be - I learn by reading and experience. I don't claim to have a superior understanding of the ins-and-outs, but I do have a pretty extensive experience with XU7s in different states of modification and I'll chime in where I can.

Take a step back and chill out mate. I'm just trying to get my head around your point. Dont take it to heart. I've not got a problem against you personally. Its your prerogative if you have one with me, but please dont talk to me in a demeaning manner, some may take offence to it...
We're all friends here.

[Dan86]

I have returned everything back to standard now and she pulls like a train! For an oversquare engine it has a lot of torque.
Has anyone dyno'd a standard 1.8 to see what the torque figures are?

[Poodle]

I had forgotten how fast your projects move, look forward to seeing this one develop fella! Do you still have the sedan-6?

[Dan86]

Yeah, I've still got the sedan. I said I'd sell it but I've not been so enthusiastic to advertise it. It looks so awesome on my drive!

[Dan86]

Grant, I polished the exhaust manifold using wet and dry sandpaper. I started with 120 grit to get through the discoloration then worked my way up through the different grades; 240, 400, 800, 1200, 1500, 2000. Then a bit of metal polish to clean off the dust.

[Dan86]

Hi folks.

I have a whistle coming from the throttle body. It only happens at part throttle and is quite noticeable from inside the cabin. I wanted to fit a green cotton panel filter but I'm worried it will just make it more obvious.

It's definately not a vacuum leak as I've already checked that, its more like a whistle from the air passing over the butterfly.

Has anyone else had this or know if its something that I can fix?

[Curt]

I have this on my GTi - it has an aftermarket PiperX bwarp cone. I've not had a chance to give it a once over yet, but like you say mine is also very noticeable at low rpm/speeds at partial throttle.

[Dan86]

I've never had a whistle on my gti6 tb so I would say its nothing to do with the design on that one.
Both the 1.8 and the gti6 use the same icv though, so maybe they whistle if they stick slightly open?

[C.A.R.]

Jeez if you ever want to sell this car I hope I'm paying attention when you do!

As for the whistling, the only things I can think would be the gasket between TB and manifold (slight leak?) or the ICV like you say, which should also have a little rubber O ring around it to seal. I can't see that you would be able to hear a whistle with the intake in place so would think it to be a leak?

[Dan86]

I've checked and double checked everything and it seems to be whistleing as the air is passing over the butterfly. Maybe its slightly worn or marked. I don't think its going to matter for much longer anyway as I want to fit the parts that I've collected and are sitting in my garage;

Gti6 inlet manifold and throttle body,
Gti6 exhaust manifold,
Gti6 catalytic converter,
Gti6 exhaust mid pipe,
Gti6 engine loom,
Gti6 cam sensor,
Gti6 coil packs,
Gti6 magnetti marelli 1ap ecu.

I would like to get the head worked by Mark Shillaber and have the ecu remapped to suit.

I would be very happy with 150hp.

[Dan86]

I read on here somewhere that the Gti6 mid pipe fits the xs cat. This is not the case. The only way to fit it is to fit the exhaust manifold and cat from the '6' aswell.

[C.A.R.]

This is true, I think the only cross-compatible part is the backbox...

What are your plans with the coolant hoses? Because of the different routing on the 1.8 the pipes come very close to the ex. manifold, which is obviously not wonderful..

I'm not sure whether a GTi6 coolant pipe setup would work, if that could be sourced. The option many choose is to insulate the pipe in something heat-reflective. This still didn't give me much faith to be honest, as the pipe insulation was still resting against the manifold itself.

You could heat-wrap the actual manifold, which would work, but looks messy and attracts dirt.

It may also be worth getting a heatshield off of a GTi6. This goes on the bulkhead and can be seen in the picture below. The coolant hose 'solution' was carried out by a 'specialist' who had done a few conversions like this. I think it looks terrible looking back and knowing what I now know - check out the kink in the pipe!

[Dan86]

Thanks for the photo. That really helps.
I want to do it as factory as possible, so I will order new gti6 coolant pipes from pug and the heat shield/mounting bracket.

The xs mid pipe is like a straw its that small. It's about 1" 1/2 at one point!
I hope the 6 exhaust system allows the engine to breath better at high rpm.

[Dan86]

I've got all of the parts ordered and on there way now. Hopefully I will have it all fitted by the end of the week.

[Dan86]

I've polished the manifold to a point at where I'm happy with it. It's not perfect but I think it will look good when fitted.

[Curt]

Bloody hell, good work!

[C.A.R.]

Whoa, that looks real nice. Shame you can barely see it from the engine bay though!

[Niall]

The gti6 heater matrix hoses will fit with a bit chopped off the ends. I had them on mine perfectly.

[Dan86]

I got the manifold in the engine bay last night. I took the subframe/steering rack off to get it in there. There may be a few scratches on it now though.






The car is back on its wheels again now but the there are a few teething issues with the water hose that goes from the back of the water pump to the metal tube that runs behind the block. There is a rubber hose that joins the two which loops out and is in the way of the manifold. I have a Gti6 water outlet and metal tube so I think I'll see if that fits, On servicebox it says they both use a 42mm 'O' ring and are held on with two bolts.


The manifold is hanging off a couple of head studs at the moment whilst I come up with a solution.

---

The gti6 heater matrix hoses will fit with a bit chopped off the ends. I had them on mine perfectly.

I will bear this in mind. Thanks for the info as it all helps.
Did you have trouble with the outlet hose from the water pump fouling the manifold at all. If you did I'd like to know how you got around the problem.

[Dan86]

F#cking great... Just been to work for a meeting, only to be told that I've been made redundant!

Time for a new leaf..
I'm thinking of starting my own bodyshop. Custom and restoration.

Where do I start!

[samass]

drop the subframe out? O.o
damn, hassle! did you consider going in from the top, like pulling the engine forward off the mounts or anything? or just thing that from underneath would be the easiest?

shit balls about being made redundant mate, seems a lot of that going on lately. good luck to you if you decide to open up a body shop

[Dan86]

It was definately easier to drop the subframe. The inlet is close to the rad as is so didn't want to risk damaging it.
Whilst the car was on axle stands I undid the six subframe bolts and disconnected the steering column joint, then lowered it down. I didn't even take the wheels off!.

On the job front; time only moves forward... so onwards

[C.A.R.]

Unlucky about the job mate, what industry were you in?

It's eerily quiet at the moment, work is slow. My old man got made redundant for the 3rd time in 4 years at a professional level too. Still, at least we have the olympics, right?!

[Dan86]

I was a plumber. I'm looking into working offshore laying electric cables in the sea bed. I'm going for an informal interview with someone who's in that line off work tomorrow.

With regards to the car, well, the gti6 manifold and exhaust improves things! it feels more free revving at high rpm. It sounds amazing too. It sings through the stainless mani which you can here through the bulkhead.


http://static.photobucket.com/player.swf...02-0-1.mp4

[Dan86]

Bit of an update; I've fitted my RFS head, cams, pulleys, exhaust manifold, cat, centre pipe and backbox. I'm running the 'teeny' xu7 throttle body, inlet and SL96 dog poo management with a modified xu7 coilpack to fit between the cams.
This is temporary as I wanted to make sure the head I rebuilt was good before forking out on management.
It was noisy when it was fired up until the tappets sorted themselves out.
Its as quiet as a mouse now.

I am surprised it runs as well as it does to be fair, and it proves that as a stop gap the SL96 will run this head/block combination.

I am thinking about using the gti ecu, engine loom, coils, inlet/throttle body coupled with the smaller injectors of the xu7 or xu10j4r. My theory is that the gti mapping is tailored to the gti cam profile based on air consumption and that using a smaller injector would compensate for the smaller air consumption of the 1.8. I know this is not ideal but it may be close enough to be able to remap the marrelli to suit the xu7j4rs.

[C.A.R.]

I thought you had forgotten our forum lol, I have already read your thread on 306gti6, you just copy/pasted that didn't you?!

Needs more pics...

[Dan86]

I hadn't forgotten, just didn't have anything to report!

Yeah I have just copy and pasted as it takes me so long to type anything out plus I would only say the same thing anyway. lol.

I will sort out some decent pics soon. What's a project thread without pics?