hey guys i have a few questions as having installed a 380 motor in 2 weeks, what power gains are they getting? fuel economy better or worse? has anybody had there's dyno'd in the 3rd gen? and how do the 5spd tippys go with the 380 as 1st gear raps out rather fast! any other pro's and cons would be awesome...

Fuel economy gets better. 3rd gen dynoed at around 160kw iirc, that's around 30 gained. No idea about 5 speed tippy. Make sure you have upgraded brakes before you do it.

Bit iffy around figures, can't remember back to dyno day we had.

http://www.aussiemagna.com/forums/showthread.php?t=89470

http://www.aussiemagna.com/forums/showthread.php?t=89470

Thanks Waz, anyways Brendan (ih8hsv) pulled a 157 with a stock fuel pump and exhaust leak. Ben (TJTime) pulled a 153 with a faulty fuel pump.
They both now have Walbros (Whinebros) so I'd say 160 would be a decent benchmark. Fuel economy hasn't suffered either even after the bigger fuel pump...

hey mate i got my ralliart back on thursday after 380 conversion

off the line it pulls a little harder then it use to but taking off from 60 it hauls

if you are hammering it everywhere the 6G75 isn't nice with fuel i found but on highway it is extremely good lol

In the 380 its will sit @ highway speeds sipping at 4-6L per 100kms!

Thanks heaps guys, so im looking at trying for a little more then 155kw soon after 6G75 any ecu tune required or beneficial? also still running standard VR-X exhaust system. what part of the vr-x exhaust system gave the 3.5ltr the extra oomf? is it the headers? muffler? cat? resonator? and will it benefit the 3.8 at all? i have seen in my searches that upgrading headers gave it a bit more but was nothing said about vr-x!! and whats a maf tune worth $ and kw wise on the 3.8?

Tune is required, at the least you need the tune off the Ralliart.

The part of the exhaust that the VRX/Ralliart/Sports had over the other models was a straight through muffler that's it.
Yes it would benefit the 3.8 but the cars I mentioned before had full exhaust systems so you won't be getting more power than them without a real proper dyno tune.

Mafless tune? No idea. Has anyone done this before?

I'd look at an LSD post-conversion if you have a manual and if it's an auto get an ext. tranny cooler.

also BRAKES BRAKES BRAKES. The single pots will not hold up. If you need to get your hands on 380 brakes + install there's a NSW member that has a set at a reasonable price IIRC.

In the 380 its will sit @ highway speeds sipping at 4-6L per 100kms!

no im sorry warren. you should not be telling people thats normal as for the average 380 it isnt. you have a freak car...
even when mine was stock it still used to sit on 8-9L/100kms at highway speeds (which is 110 for the record, not 80 :P)
with all my mods it still sits on about 9L/100kms but i have quite a bit more oomf doing it :P (remember ive added lots of unsprung weight with rims and brakes)
in the lighter magna i can imagine it might be a little more frugal but im not sure how much...

Oh sorry yes my HIGHway econ seems lower than many 380's (also as side note my car idles lower than Kif's)

no im sorry warren. you should not be telling people thats normal as for the average 380 it isnt. you have a freak car...
even when mine was stock it still used to sit on 8-9L/100kms at highway speeds (which is 110 for the record, not 80 :P)
with all my mods it still sits on about 9L/100kms but i have quite a bit more oomf doing it :P (remember ive added lots of unsprung weight with rims and brakes)
in the lighter magna i can imagine it might be a little more frugal but im not sure how much...

6.9l/100km from syd to brisbane in TJ. And i highly doubt warren is getting averages that low in reality

I did on monday going to Canberra!

anyway to Z 155kw @ the wheels is pretty good considering I get roughly 120kw

If you have extractors, straight through exhaust, a decent intake setup & a ecu tune on 98 you should be good for around 163KW ATW which is what mine got before the blower & that's auto. Manual expect a bit more.

I'm getting 7-8L/100km on the highway and 10-11/100km city with my 3.8L-M. My car is an AWD.

I'm getting 7-8L/100km on the highway and 10-11/100km city with my 3.8L-M. My car is an AWD.

with sprintex and mivec heads??? lol

Just the mivec. Sprintex is December.

Hi mate,

I've got the 6G75 in my TH wagon (but it is manual). Mine is probably around the same weight as your TJ auto sedan.

Auto trans is going to be a bit of an unknown, but from my experience:

Fuel Economy is good still (I do a good mix of M5 and urban roads). I average about 9.7 Lts per 100km and that's with an average trip speed around 50 Km/h, and I can't resist giving it a good squirt here and there. I'm getting very close to 700km on a tank at moment, but if driven sedately 100% of the time it would do over 700km easily.

Mine dyno'd with a Ralliart Tune at 159.7 Kw with the only mod being a set of HM headers.
I found these headers cleaned up the exhaust note and it didn't drone as much (HM Headers, the company are well regarded in terms of their understanding of NVH issues) , so given you have an auto I'd suggest these, even though they are a tad expensive. Good quality though!

My stock fuel pump seems to have been ok so far.

I don't know how much extra Kw a tune is going to get on top of the ralliart one (maybe 5-10kw?), but I'm finding the Ralliart tune is a little rough, mainly down low.

You will need really grippy tyres as traction is a problem.

Brakes I'd recommend you get some 380 fronts fitted at same time as engine.

My 0-100 best is 6.42 sec, but's without much traction. Reckon I'll get close to 6 flat once sorted.



PM me suburbs where you live and work and if you want may be able to meet up and you can have a look and I'll take you for spin.


Cheers.