4.8 owners...

[smicko]

Any experience with exhaust mods in Perth? I'll be picking up an 07 ti tomorrow that has a knackered centre muffler so I figured I may as well drop in a set of extractors and a new system.

The one quote I have so far is $2100 for a stainless system ex cat and $1800 for mild steel ex cat. He also recommended to retain standard cat as opposed to going hi flow as in his experience that is when people start having problems with them.

This thing is currently running at 12-13lt/100 so I really don't want to screw with that if possible. Pretty happy with current power but plan on doing the PVA mod to open up the bottom end on Saturday.

Has anyone gone from standard system to hi flow and have comparative consumption figures?

Also any recommended vendors in Perth?

Many thanks...

[threedogs]

You sure you're getting 12-13lt per 100 K out of a 4.8 petrol?
most here are getting 20-25 ltr per 100Ks.
Look at vendors for Scotts rod exhausts and Beaudesert exhaust they have DIY exhausts.
I get 12.8ltr per 100Ks and Mine is 3lt TD

[TPC]

I have never heard of anybody getting that good economy out of a 4.8, a mate was getting 20-22 around town out of his.

[BigRAWesty]

Agree with both above. Someone is having you on mate.. Those figures are diesel figures.. I've never known a 4.8 to get below 20L\ 100k..

Sent from my C6603 using Motorculture mobile app

[threedogs]

That's not gas figures is it, just seems way too good to seem plausible

[Clunk]

That's not gas figures is it, just seems way too good to seem plausible

Would be higher if it were gas Surely!!!!???

MC..... It isn't Tappa but it's all I've got!!!!!!! :'(

[smicko]

Yes I was somewhat surprised myself and no one's having me on as they were my figures I took it for a drive for 130k's combined highway and town. Filled it to the neck, zeroed it drove 130k and refilled it to the neck at the same servo, took 16.1lt. That's 12.4 lt/100, hence me asking if anyone had personal experience with changing from a standard exhaust system to extractors and a high flow.

I was fully expecting 17-25lt/100 and did the test in the first place because I had queried the owner as to what sort of mileage he was getting and he said 8k's/lt, of which I was understandably skeptical. Other than running 33's it's a stock standard 2007ti.

Back on subject, any 4.8 owners who have gone form standard exhaust to high flow with comparative figures please?

Cheers

[BigRAWesty]

We'll I'm guessing Its gutless because Its lean as a mofo. Blocked injectors or fuel filter.
Before spending money on exhaust, change fuel filters, and have the fuel system checked over.
Get a tune and.you should have a power house..

Sent from my C6603 using Motorculture mobile app

[Clunk]

We'll I'm guessing Its gutless because Its lean as a mofo. Blocked injectors or fuel filter.
Before spending money on exhaust, change fuel filters, and have the fuel system checked over.
Get a tune and.you should have a power house..

Sent from my C6603 using Motorculture mobile app

Huh, don't get it....... Who said it was gutless?????? Or am I missing something?????

MC..... It isn't Tappa but it's all I've got!!!!!!! :'(

[TPC]

If its not gutless why would you change the exhaust on a 4.8 that gets economy that good?

[smicko]

We'll I'm guessing Its gutless because Its lean as a mofo. Blocked injectors or fuel filter.
Before spending money on exhaust, change fuel filters, and have the fuel system checked over.
Get a tune and.you should have a power house..

Sent from my C6603 using Motorculture mobile app

Kallen, as I said I'm pretty happy with it's power, I'm sure I can wring more out of it if I want to, but I'm happy with it as is. It's got far more grunt than I can make use of and retain my licence. If you're familiar with the PVA mod you'll understand that all it does is allow the motor to breathe better under 2000rpm, making the auto more responsive at lower revs (and supposedly better economy in the auto which I find hard to swallow, given my current figures). I'm not after a fire breather, I'm chasing a tourer that is offroad capable and returning the best mileage I can get.

I've been looking for a 4.8 for a couple of months and have driven more than 10 of them ranging from '02 through '10 and from 16-48 grand. This one is a cherry and runs the best out of all of them, it is also the ONLY one I've driven that hasn't already had exhaust mods done, hence my query.

I've run it past my mechanic who called it as one of the best he's ever seen. I also stated that the centre muffler is knackered, perhaps I should extrapolate that a bit to say it has a hole in it and whilst I'm looking at replacing that I may as well chuck on headers and a full system, IF ITS NOT GOING TO SCREW WITH MY MILEAGE.

Do you own a 4.8? Have you owned a 4.8 that you have modified from standard exhaust system to hi flow? Do you have comparitive fuel consumption figures for that?

That was my query.

Is it really that hard to not be such a twat?

#edit the above two posts came in before I'd finished replying to Westy, hope it explains things better.

[Clunk]

I'm just a lowly GQ TB42E owner who gets pee poor economy........... but if wre e me who owned that rare economical beast of yours, i would just be replacing the centre muffler and leaving the rest alone but thats only my opinion and I'm far from experienced in such matters.

Hopefully, someone who actually knows will be able to offer more

[BigRAWesty]

Sorry mate, I miss read the first post.
It's hard to say with cars these days what will do what, because of the computers they are constantly changing the setup to match conditions and driving style to get the best output.
You may get a small increase with the added air flow, as the computer would be trying to counteract it to keep its factory limits.

If the budget permits your best option would be chip and exhaust. Some chips are adjustable, so you pick the severity of power. More power, more fuel, less power less fuel.

Keep us informed though as at 13L/100 that things a keeper...

Sent from my C6603 using Motorculture mobile app

[oncedisturbed]

I have an 09 4.8 with a 3" cat back exhaust installed by mettams in balcatta which cost $650 installed.

I would like to know how the hell you can get 12-13L / 100 out a 4.8 as others mentioned 20-25L is average and that's what I get out of mine. You may be able to get extractors for your as well depending on the number of O2 sensors you have, I know the 06 model only had 2 installed and there are extractors now suitable to fit but the 09 model has 4 O2 sensors and nil extractors available as yet.

If you have 4 O2 sensors, leave the original headers in place as you will / may end up with engine failure, that is straight from the guys from Manat exhausts and several other exhaust mobs in Perth I have spoken to until an extractor is released that is compatible


Never underestimate the power of the Tap.

[smicko]

I'm just a lowly GQ TB42E owner who gets pee poor economy........... but if wre e me who owned that rare economical beast of yours, i would just be replacing the centre muffler and leaving the rest alone but thats only my opinion and I'm far from experienced in such matters.

Hopefully, someone who actually knows will be able to offer more

Might be sage advice I think, I really don't want to dick with it too much when it's running like it is.

[smicko]

I have an 09 4.8 with a 3" cat back exhaust installed by mettams in balcatta which cost $650 installed.

I would like to know how the hell you can get 12-13L / 100 out a 4.8 as others mentioned 20-25L is average and that's what I get out of mine. You may be able to get extractors for your as well depending on the number of O2 sensors you have, I know the 06 model only had 2 installed and there are extractors now suitable to fit but the 09 model has 4 O2 sensors and nil extractors available as yet.

If you have 4 O2 sensors, leave the original headers in place as you will / may end up with engine failure, that is straight from the guys from Manat exhausts and several other exhaust mobs in Perth I have spoken to until an extractor is released that is compatible


Never underestimate the power of the Tap.

Have you noticed much change in performance and consumption OD? Also have you done the PVA mod and did that do much?
Cheers

[threedogs]

Its one freak of a 4.8 that's for sure.
so you have heaps of grunt too . Something some where is wrong
Extractors will unleash the beast as OE exhaust will be choking it.
Might have to get Stropp or another Perth member to check it out lol
IMO no one will have those figures not even Nissan

[oncedisturbed]

No difference in economy but a bit more power. No pva mod as i have read many mixed reviews on it and a lot that have done it, removed the mod.

A high flow cat is next on the cards


Tap, Tap, Taparoo

[smicko]

150k's today in mostly shitty stop start peak hour traffic with maybe 40 of those k's cruising in top.
19.75lt/100k's. It may end up on injected gas yet.

Heading up to Wedge tomorrow so will see how it goes cruising over 300k's or so. Geez they have some poke hey?

[Clunk]

150k's today in mostly shitty stop start peak hour traffic with maybe 40 of those k's cruising in top.
19.75lt/100k's. It may end up on injected gas yet.

Heading up to Wedge tomorrow so will see how it goes cruising over 300k's or so. Geez they have some poke hey?

The 4.8 would be my choice after the td42 but they're stupidly expensive to buy. I'm not a big fan of gas either, from what I've read it more hassle than what it worth and too harsh on engines but some folk swear by it.

MC..... It isn't Tappa but it's all I've got!!!!!!! :'(

[smicko]

It's easy to see why everyone is getting 20+ with these things, it's really hard to have all that poke on tap and not use it. It's especially hard when you've come from driving small turbo diesels that just love to have their neck wrung. Perhaps buying a 4.8 whilst being on double or nothing was not such a great idea. It's a really pleasant change to be able to overtake safely though.

Did 360 highway k's today, mainly on cruise at 113km/h with the odd 120+ squirt to overtake, returning an average of 18.76lt/100 or just over a $100. Ouch, expensive surf, used to cost me $50ish in the Disco.

When I got that 12.2lt/100 the other day I was was on a mainly highway run on cruise at 90k's, with a bit of stop start at traffic lights, so I 'spose I should do a test run at 90k's to see If I can achieve it again.

On another note I did the PVA mod this morning and it definately opens up the bottom end.

[Clunk]

Aye it's time to learn to drive like your grandmother lol

My folks went to the Google Play Store and all they got me was this lousy Motorculture App!!!!!!!

[Bulbous]

Did 360 highway k's today, mainly on cruise at 113km/h with the odd 120+ squirt to overtake, returning an average of 18.76lt/100 or just over a $100. Ouch, expensive surf, used to cost me $50ish in the Disco.

When I got that 12.2lt/100 the other day I was was on a mainly highway run on cruise at 90k's, with a bit of stop start at traffic lights, so I 'spose I should do a test run at 90k's to see If I can achieve it again.

On another note I did the PVA mod this morning and it definately opens up the bottom end.

Yeah, that's a bit more like it. I spent a bit of time trying to get the best possible mileage out of mine - mainly out of idle curiosity.
Mine's a Manual, and if you keep it under 2000 RPM it will give good mileage (about 80KPH) and only drops of a bit up to 2500 RPM (100 KPH).
Once you start going over 3000 (about 120 KPH) then it starts to lose out which is not surprising since that's where the power starts.
I gave up trying to get good economy, cos you only have to race one Lambo to waste a months worth of savings.

[oncedisturbed]

What benefit did you get out of the PVA mod?


Tap, Tap, Taparoo

[threedogs]

Something is missing here, either the wrong motor, something. I worked out 16.1 for 130k to be 12.38. Shite I can only get 12,8 around town.
This is on camera hey liked that punked show. There's no logical reason why a 4.8 gets 12.38 per 100k. I don't even think the factory quoted those figures.
Even fudged I'd be sceptical at 16/100. You say 12.3 so who are we to dispute it, don't change a thing as you are the luckiest owner of a 4.8 in Australia bar none
Sitting on 90 is what I missed.

[smicko]

What benefit did you get out of the PVA mod?


Tap, Tap, Taparoo

More torque down low, pulls away from dead stop far better and holds in gear longer before changing.