[Dan`]

so the new coily zook seems to be sucking down the fuel and just generally gutless as shit, wont rev and just seems all around pretty horrid to drive. im not sure how much this is influenced by the fact ive been driving the GTI powered drover for the last 15 years and that to me is just how a zook "should" feel now but the best im getting is 10L/100 and i have been driving really sedate in it but one thing ive noticed is that the exhaust is almost completely silent to the point where even once the secondaries open i can hear the induction noise over any exhaust. again in comparison the drover has extractors and a 2" sports exhaust versus the stock coily, but this seems to me to be excessively silent.

so i guess what i want to knowis, is 10L/100 "normal" and secondly is the stock exhaust really that quite on these things? im beginning to think the cats melted or one of the baffles in the zorst has collapsed or something.

[Chop]

Sounds normal mileage to me, especially if there is bigger tyres, lift and accessories bolted on?

[Dan`]

yea bigger tyres, 225/80/15's. with the same wheels/tyres the GTI powered drover was getting much better economy, guess thats the better designed, more efficient motor and EFI kicking in there. everything else on the coily is stock (for now)

[greenzook89]

Standard exhausts are fairly quiet. Mine has no exhaust noise.

What size tyres are you running?

10l/100 is around the average of all the Sierras I've owned.

[Dan`]

greenzook89 wrote:

Standard exhausts are fairly quiet. Mine has no exhaust noise.

What size tyres are you running?

10l/100 is around the average of all the Sierras I've owned.

seems mods are fucking with my posts again, i thought id already answered that. 225/80/15's which is the same wheels as were on the GTI drover which was getting much better economy. im currently getting under 300km per tank and ive been crawling it around, been forced to take one of my broken dogs everywhere with me so i cant drive fast in the slightest in case she busts her leg again. in the drover i hammer the hell out of it and still make almost 400km from the same size tank.

96 coily is stock as a rock and 86 drover is stock apart from the GTI conversion and the 2" exhaust

[greenzook89]

225/80 are around a 29 inch tyre. So you have added tyre but are still running stock gearing. Have you accounted for the speedo difference when getting odometer readings?

Either way a ungeared coily on 29s will be a slug on road. Before i geared mine I hardly used 5th. Now I have 4.16s its back to how it was stock.

[Dan`]

yea only quickly versus the GPS on my fone, the speed is way out but the odo reading still seems to be correct over a 10km trip. need to do a longer trip to double check.

i dont mind having to drop back a gear to get anywhere but that when i do the stocker dosnt seem to want to rev. above about 3-4000rpm it hits a brick wall unlike the gti which comes alive, stock gears in the drover were perfect.

but if 10/100 is what i should be expecting i think the rest is just not being used to the asthmatic stocker.

[31zook]

I thought that the speedo and odometer were driven off the same input, so if ones out they both would be?

[Dan`]

while they are both driven off the same input (the speedo cable) they are separate devices inside the cluster. usually speedos are out by anything from 5% upwards where as odometers usually tend to be more accurate. if i find the odometer is reading correctly over say a 100km trip ill just pull the needle off, drive at 100kph via gps then put the needle back on to read true 100kph. have had to do that in other cars which have been quite far out.

[Jezza86]

Is it runing rich?

[Dan`]

havnt put my wide band on it yet but it dosnt seem to be.

[jdk81]

Standard exhausts are quiet.
10L/100km is about right.

Your gti powered, with bigger tyres and stock gearing will be better as its efi and being taller geared probably closer to the engines sweet spot of efficiency.

[MrRocky]

Stock 1.3 is so far from the high comp twincam efi motor, whilst the block might be the same everything else is different.
2" exhaust on a 1.3 carb motor helps it rev a bit more freely but extractors are pointless unless it replaces a cracked manifold or they are well made (not ebay). Add some larger tyres and you will be lucky to get under 13ltrs per 100km

[Dan`]

im well aware they are completely different motors in every respect but i was just a little shocked that crawling around in the stocker uses noticeably more fuel than thrashing the twin cam around. its almost depressing.

part of the reason for starting this thread was i have been thinking about putting an exhaust on it anyway as that will need to be done later on anyway, remove the cat and run some nicer high flowing muffler on a 2" system i think would be ample even with a motor change in the future.

[MrRocky]

Economy will only get worse with bigger exhaust on carby car

[Gwagensteve]

Dan` wrote:

while they are both driven off the same input (the speedo cable) they are separate devices inside the cluster. usually speedos are out by anything from 5% upwards where as odometers usually tend to be more accurate. if i find the odometer is reading correctly over say a 100km trip ill just pull the needle off, drive at 100kph via gps then put the needle back on to read true 100kph. have had to do that in other cars which have been quite far out.

Are you sure in the case of a Sierra?

I don't think they are. I've had quite a few speedos apart fitting VSS etc.

[Dan`]

Gwagensteve wrote:

Are you sure in the case of a Sierra?
I don't think they are. I've had quite a few speedos apart fitting VSS etc.

yes steve, they are not locked.. even at rest...

what i meant is that the needle of the speedo is not directly aligned with the odo in as much as you can pull the needle off and make it read any speed at any speed you like. if at rest you pull the speedo needle off and reattach it to show 80kph (while your still not moving), then drive at 100kph on the speedo, in an hour you will not have travelled 100km but only ~20km.

the bit that spins the needle does not directly spin the numbers for the odo even tho they take the same output from the speedo cable
id need a pic of the internals to explain it better... but at some point inside the cluster the drives take a Y and branch off to each part

[Dan`]

MrRocky wrote:

Economy will only get worse with bigger exhaust on carby car

not the experience ive had in the past, in fact ive always seen better economy with a free flowing exhaust. with the stock manifold i cant imagine a big difference. only time ive seen mods like that causing negatives is when people end up driving them harder.

either way, the stock motors days are numbered and just to get a bit freer reving performance would be worth it in the short term

[tonyevans]

If the wheel/tyre is a larger diameter then it will tur less times per kilometer and that is what the mileage output counts. So bigger tyres = smaller K reading the speedo can vary because it has a magnetic connection not mechanical.

[MrRocky]

Dan` wrote:

MrRocky wrote:

Economy will only get worse with bigger exhaust on carby car

not the experience ive had in the past, in fact ive always seen better economy with a free flowing exhaust. with the stock manifold i cant imagine a big difference. only time ive seen mods like that causing negatives is when people end up driving them harder.

either way, the stock motors days are numbered and just to get a bit freer reving performance would be worth it in the short term

Its not an opinion, ive had about 20 sierras
Economy will suffer with a 2" exhaust unless gearing is addressed, only then is it possible to bring numbers down

[Chop]

Im not even sure why you asked, you seem to know the answer according to your replies and no matter what seem like you'll do the opposite tobwhat people say/ recommend.

[Dan`]

wtf are you on about? i asked about consumption and if the stock exhaust was meant to be so quiet, and proclaimed surprise that its normal for the stocker to use more fuel than a hard driven GTI. i had no idea that they were so thirsty. at no time have i said anything otherwise. how was that me "knowing the answers".....