More grunt from 1FZ-FE

[amichie]

Do the headers then the cam.

First step on an NA inline 6 is to change the headers to long primary length headers.

Crush bent or mandrel bent doesn't really matter but primaries must be long.

A longer duration cam combined with the stock exhaust manifold will make it go worse almost over the entire rev range.

[andrew_mx83]

But I don't want to ditch the LPG, Removing the ring is a problem, it's locktighted to the throttle body and the air cleaner hose has been shortened to fit so not an easy thing.
Any idea of cost of Impco 425 and L converter? I thought of going to injection if the gov rebate would apply but as it's already converted I'm not sure. One mob I asked haven't got back to me after 2 weeks. Not a good sign. Any ideas on aftermarket cams for these motors?
Cheers,
Alan.

about a grand for both, brand new & retail.
if u can find them second hand or get a good deal on new ones it will be a lot cheaper.

mine costed me about half that new, but it took a lot of legwork and ur on the other side of the country so i couldnt recommend anyone unfortunately

[abently]

I agree, camshaft upgrade is the last thing you should be doing.

Can you post up the dyno graph of the LPG tune ? We/you should then be able to judge how bad the current gas ring restriction is possibly and the real viability of an upgrade.

Hopefully the graph has the rpm axis otherwise your going to have to pick two speeds (kph) and tell us what rpm they are otherwise someone will have to work it out backwards from tyre, diff and gear ratios... lol

[Vios-GT_07]

http://www.toymods.net/forums/showthread.php?t=46146

?

[TooF]

wow thats really surprising, i dirve a 1fzfe 100series for work and it pulls up everything loaded to the hilt, towing you name it. stock as a rock and its a total beast you jsut cant stop the thing.

id be pointing my finger towards the gas :S never been a fan of the taxi juice

[alanrlow]

Do the headers then the cam.

First step on an NA inline 6 is to change the headers to long primary length headers.

Crush bent or mandrel bent doesn't really matter but primaries must be long.

A longer duration cam combined with the stock exhaust manifold will make it go worse almost over the entire rev range.

You know I had never given the exhaust side of things any thought at all. Makes a lot of sense tho. It has the standard manifold and skinny little pipe. I wonder if that's contributing to why I can floor it on a hill drop it back to 2nd or 1st, rev like a bastard and actually feel like it's LOOSING power.

[alanrlow]

I agree, camshaft upgrade is the last thing you should be doing.

Can you post up the dyno graph of the LPG tune ? We/you should then be able to judge how bad the current gas ring restriction is possibly and the real viability of an upgrade.

Hopefully the graph has the rpm axis otherwise your going to have to pick two speeds (kph) and tell us what rpm they are otherwise someone will have to work it out backwards from tyre, diff and gear ratios... lol

Unfortunately his printer was broken so no printout, he showed me the screen shot and I managed to write down the before and after figures (this was for the Unichip installation) but no graph.
I want to cruise at 85-95kph which equates to 2000-2050 rpm with my tire profile setup.

[alanrlow]

wow thats really surprising, i dirve a 1fzfe 100series for work and it pulls up everything loaded to the hilt, towing you name it. stock as a rock and its a total beast you jsut cant stop the thing.

id be pointing my finger towards the gas :S never been a fan of the taxi juice

Don't get me wrong, it goes ok unloaded. It's just with a full length roof rack with 2nd spare tire, boat, extra fuel up top and the back from drivers seat to tail gate loaded to the roof and a 2500kg + van on the back it's not so nimble. I recently went over Mt Kosciusko, mostly in 1st and once or twice in low range.
Don't knock the taxi juice. I used to own an XF falcon ute full out modded for gas and it pulled like a school boy. Show a clean pair of heals to a lot of V8's

[amichie]

One of the australian header manufacturers makes good headers for an inline 6. I will look it up and post it here.

The inline 6 has a unique problem when it comes to exhaust header design.
The exhaust ports are usually collected as a set of 3 cylinders front and rear. With the standard firing order 153624 you get alternate firing in the front and rear sets of three. This means that you get exaust pulses at 240 crank degree intervals. So if your cam duration is in excess of 240 degrees (which is a mild cam) you will get high pressure exhaust pulses ocurring at overlap on the previous cylin der that fired. As you can imagine this hampers any scavenging effects. Good news is the longer the primaries the smaller the effect.

Bottom line is get headers with long primaries and even better if you can find a set that are configured as three sets of two cylnders.

[TurboRA28]

Have you driven another 1fz to compare? I tow a car trailer with the celica on it with mine and is awesome.

[cambelt]

First step is to upgrade the gas system . Impco 425 and convertor , dont worry about headers or cams yet . Depending on what you do headers in 4WD,s crack all the time when offroad , the standard 1FZ exhaust and manifolds do a great job left as stock .
Dave

[wa5]

have you had it on a weigh bridge to see how much it weighs when fully loaded?

[alanrlow]

have you had it on a weigh bridge to see how much it weighs when fully loaded?

Hate to think. I know the van is around 2500kgs, what the cruiser weighs is anyone's guess. I've got 2 spare tires, 100l gas tank as well as the petrol, boat, heaps of camping gear, 50l of water, couple of gas bottles, 2 jerry cans of fuel and 2 people. You figure it out. I will try to find a weighbridge tho just to see. Won't matter as the missus reckons we can't loose any weight.

[wa5]

So you probably have an all up weight of around 5 tons, maybe a bit more? and you are wondering why it struggles?

[hemi twofifteen turbo]

2000rpm is a little low for towing power at 85/90km/h. I'd really recommend changing to a lower ratio diff. It's going to be the simplest, most cost effective and bring the largest improvement you can get for towing short of major engine mods. It's basically what your doing with your gearbox having to downshift all the time.

As for the gas -- a gas ring type setup isn't all that restrictive compared to the snorkel type. They require very little vacuum to get a gas flow. The problem is they are pretty basic at metering fuel. Due to the wide margin of error you can have with a gas tune that still 'seems to run right' this is often overlooked, but I guess it must be setup ok if giving similar power results to fuel. The snorkel type mixers are better, but more of a restriction than a gas ring. The impco 425 is defiantly one of the better designs, but again for the money vs. gains it's not going to cut it. Flow may be restricted at high revs but the majority of the time at 2-3k the throttle plate is going to be the biggest (or at least should be) Even the best gas system isn't going to make it tow better than it would on fuel, and it can't do it on fuel so there's no point looking here.

Headers are going to cost $200-500 and IMO not make enough of a difference, the exhaust upgrade may be a worthwhile prospect if damaged/blocked etc..

Again I would highly stress changing diff ratio's to something more suitable for towing 5 ton loads.

Rather than do anything else though you could invest all your cash in a dedicated LPG turbo conversion and win in all areas!!

Hope this helps!