AU I6 NA, what’s realistic?

stiddy · 10-10-2007, 08:08 PM

Im about to get my car back finally after long awaited exterior/bling mods on my XR6 and looking to start some real performance mods. As some of you know I had a turbo kit that I got rid of for my own reasons so now, I want to get a move on with some NA mods. I’ve got the wild cam and exhaust. Extractors and edit will be in the car by the end of the year.
What I want to know is if I get the engine done what sort of ET can the AU I6 realistically get without being undrivable? At the moment I’m getting 14.9’s basically stock. What’s the AU I6 got in it? Seems the best so far is a 14.2 and a claimed but not proven 13.9. Which honestly is fairly pathetic. Is that it? Is that the best an AU I6 can go NA?

Mods when I ran 14.9:
3inch highflow cat, 3inch mandrel bent exhaust with 1 small sports muffler, 3inch mandrel bent intake from throttle-body to pod in airbox.

Mods since last at the track:
Rebuild/strengthed T5, 5 puck brass button clutch and billet alloy lightened flywheel, 3.7 diff gears 4 pinion LSD center and billet axles, a bloody wild surecam and Fusion Speakers lol. Also Kingsprings and Koni shocks.

Mods to waiting:
Difillipo extractors with 3inch collector, Edit with custom tune, a Ripshift shifter and some sticky tyres.

Cheers,
Stiddy

ayeyew · 10-10-2007, 09:44 PM

After you modify the valve train and with a lot of porting and head performance alterations, increase the compression, get decent valve springs, get a decent computer, a 2700 Hi-Stall & LHM and you would prolly be looking at around 170-180RWkW

Bring on the 13's!!

stiddy · 10-10-2007, 10:11 PM

2700 high stall? Erm.. Ive got a strengthened T5 manual buddy.

I just find it a bit of the joke, driving around in (so called) high performance cars, when the newly released Hilux 4L V6, Magna 380, and whatever else is out there can flog us STOCK.

WSID last wednesday... there were NA civic's running very low 13's, VW golfs running mid to low 14's. Is it that hard to be done from a 4L falcon?

**Mechan1k** · 10-10-2007, 10:32 PM

If you want quicker times .... I do suggest auto.

My mate Jase with the Heritage green EL Fairmont is about to put a C4 in it and get rid of his T5.

So far the list is extensive when it comes to mods ... really through between EL and AU ... mechanically you should be able to do the same sort of work ... the only thing suffering with the AU is the weight it carries.

Last time Jase ran with the manual ... he managed a flat 14 sec run ... after the diff ratio change he forgot to change the speedo sender in the box ... hitting the 180km/h limiter prior to making it to the line ... it went into LHM ... and he coast over ... for a flat 14 ... so if he actually had the sender in there ... it would have been well into the 13s. (all this still with the factory ECU .. no edit still).

He is trying to get the launch right though ... even though he's a pretty decent steerer ... he thinks he can do better ... and the C4 will help in this regard as well.

The AU's problems ... it uses a tractor motor ... and it's a heavy bugger ... there's the 2 problems there.

Oh ... another thing to watch out for ... snapping driveshafts on launch ... Jase has done this as well on his 14.1 run.

ayeyew · 10-10-2007, 11:51 PM

Quote:

Originally Posted by stiddy

WSID last wednesday... there were NA civic's running very low 13's, VW golfs running mid to low 14's. Is it that hard to be done from a 4L falcon?

That's like comparing a Falcon to a 6.4L Sbarro Monster and asking the same question...

SIKSIX · 11-10-2007, 04:18 PM

Stiddy if i had more money to spend on my car a would rebuild the motor with flat tops if possible, get everything balanced, strengthend rods+bolts, so it can sing at 7000+ shave like 5-6mm off the head and then if there is some spare change do a six throttle conversion.

And then chase around some gen3's.

The Monty · 11-10-2007, 05:15 PM

Im asking the same questions Stiddy.
I have an auto, but to get me into the 13's, this is what I think Im going to need.
Please bear in mind, I know it wont be classified as a "street" car when I run it at the strip, but, Im at the strip, a drag racing facility, not on a road, so I like to think that if you take a car to the strip, you are chasing whatever time is possible from the car you are driving, not whatever time so and so ran with his toolbox in the back.
Intake - Im using 3 inch S/S, into K&N Xstream pod, in the factory box, front cut out, and tickford snorkle. Soon to be changed to a GnD style box, but customish made.
Exhaust - The big can of worms here, but Im using a 3 inch cat, 3 inch mandrel bent cat back, with a single straight through Redback 3 inch "race" muffler, and Pacie comps (4480's)
Cam - The cams that seem to be getting the decent results are the surecams at the moment, be it the one you use, or the one OED (has run 13.8 AU motor, but ED shell), and Stav use. Others would be the DEV4 or 5. Also Valve springs.
Tune - Edit (CAPA flash sct software) custom tune, there isnt much else out there, bar the new Sniper software, which hasnt really been tested much as yet, or a stand alone ECU.
Head - Maybe some porting, Im not really sure if there are many gains to be had with the head, but Im about to find out

Injectors - Stav saw them peak out in the high 160 RWKW region I think, so a set should probably be used to be safe, Im going to try and use F6 32 lb's, as the Mong uses.
Diff - An LSD or a LOKKA, a LOKKA is probably more suited to the kind of driving I do, and doesnt need constant rebuilding, and repacking.
Gears - 3.9's or 4.1's. The 4.1's will probably be changing into 4th gear, and cost you time over the 1/4 (remember Im talking auto, not your manual), and you will need a speedo corrrector.
Auto - Strengthened, and be using a 3g plus stall, matched to the cam of choice.
Springs / shocks - Maybe think about a softer spring/shock combo on the drivers side to help it squat and take off.
Slicks - An E/T street radial would probably suffice, not needing as much heat as a full on slick, so wouldnt punish the gearbox and diff as much.
Weight - Spare, subs out, along with all loose Items. If you wanted ( I may down the track not sure yet) rear seat, door trims, sound deadener, console, etc. I know people say there isnt much gain there, but any gain is a good one. Even the driver, if you are big, loose some pounds, itll have you feeling good, and your car will love you for it.

Thats what I can think of, I cant see how it isnt possible to get into the 13's, it mustnt be that hard, for me, its a money thing, Im an apprentice, and Im trying to buy a house, so thats where my problems lie.

The Monty · 11-10-2007, 05:18 PM

Also, probably add in a two piece tailshaft (for me anyway), I dont like the idea of it breaking.

**Stav** · 11-10-2007, 05:37 PM

Quote:

Originally Posted by stiddy

2700 high stall? Erm.. Ive got a strengthened T5 manual buddy.

I just find it a bit of the joke, driving around in (so called) high performance cars, when the newly released Hilux 4L V6, Magna 380, and whatever else is out there can flog us STOCK.

WSID last Wednesday... there were NA civic's running very low 13's, VW golfs running mid to low 14's. Is it that hard to be done from a 4L falcon?

Who has seriously tried and completed their mods ? Everyone so far haven't finished their normally aspirated project or looking at the forced induction way. Fair enough it is cheaper to go forced and get better results. However it seems that the au six has been put in the too hard basket and that is what makes this motor such a challenge to work on. On the other hand to ba motors are all 13 second cars just waiting to be done up properly. The gauntlet was thrown down by me well over a year now and despite the talk theres been no 13 second au yet on this forum.

**Stav** · 11-10-2007, 05:41 PM

http://www.fordforums.com.au/showthr...light=gauntlet

remember this.?

Allen · 11-10-2007, 05:42 PM

Quote:

Originally Posted by SIKSIX

...shave like 5-6mm off the head...

I hope you aren't serious there... :S Half a centimeter?

With a lot of work, the AU 4.0 would be able to see 200RWKW, but drivability would definatly suffer.

You've done a fair bit of work to the driveline, which is half the battle... most people go silly chasing power, and forget about the driveline, and then complain when it goes slow or doesn't hook up...

FS5 · 11-10-2007, 06:03 PM

i can't ,see why no one has run a 13 yet .there are a couple of cars on the forum that are running enough mph to do it.
i think people don't focus enough on the setup of there car enough,getting it to hook up and go.its funny that the quickest au is running a stock head and hp camshaft.

Sapper · 11-10-2007, 06:41 PM

You seem to be going along the right track stiddy. There are 2 things that I think are most important to remember when planning modifications:

-Power(W) = Torque(Nm) multiplied by shaft rotational velocity(rad/s), remember that for a certain amount of power, you can trade torque for RPM and vice versa. (to go from RPM to rad/s, take the RPM, divide by 60 and multiply by 6.28)

-(For the drag strip)For the lowest ET and highest trap speed (for a set weight) you want the highest average wheel torque throught the part of the rev range you use down the quarter. Remember that increasing the rev limit enables you to have shorter gears which increases your torque at the wheels throught the entire rev range.

In regards to what I think the I6 motor is capable of...

In practical terms, I think that 6500rpm is the highest you would want to go. 6200rpm is a good trade off. Remember that as you increase RPM, you will need a cam with overlap and valve timing which will reduce your dynamic compression compared with a milder cam.

For an engine that revs to 5700 rpm, I persoanlly think that a 450Nm peak is attainable. The 'Go the Mong' saloon car gets almost 500Nm (by my calculations) with a redline of 5800rpm. For an engine that revs to 6200 rpm, I think that a 430Nm peak is attainable. For an engine that revs to 6500 rpm, a 400Nm peak may be attainable.

Stav made the comment to me at the AFF Dyno Day that the BBM is a major factor in restricting the power of our engines. I think this comment has merit since the lengths of the intake tracts are tuned for around 3300rpm and around 4500rpm. Big revving motors will benefit substantially from a modified BBM or new intake manifold.

180rwkW is certainly attainable. 200rwkW is ambitious but by no means impossible.

Taking a look at your car:

Since you've got 3.7 gears already, I reckon aiming for around a 6200rpm rev limit would be the go. From here, pick your parts to give the most torque possible in the 3500-6000 rev range. Make sure your engine can breathe properly right up to 6200rpm. Have the length of your intake tracts such that wave tuning is best in the 4500-5000rpm range. [Side note: as the RPM increases, the rate of change in optimum intake length decreases] Have a cam that works best in the 3000-6000rpm range. From there, try to get the most dynamic compression possible, get the best airflow in and out of the combustion chamber possible, and get the best fuel burn possible.

I reckon your drivetrain is about as good as you can hope for which will be a great help.

For a manual AU XR, is seems to me that 180-190rwkW is what's required for a 13sec pass. A well set up car with 170rwkW may also be able to get there. As a reference, BigAl's ute made it into the 13's with 175ish rwkW.

That's what I think anyway...

FS5 · 11-10-2007, 07:00 PM

Quote:

Originally Posted by VenomST

You seem to be going along the right track stiddy. There are 2 things that I think are most important to remember when planning modifications:

-Power(W) = Torque(Nm) multiplied by shaft rotational velocity(rad/s), remember that for a certain amount of power, you can trade torque for RPM and vice versa. (to go from RPM to rad/s, take the RPM, divide by 60 and multiply by 6.28)

-(For the drag strip)For the lowest ET and highest trap speed (for a set weight) you want the highest average wheel torque throught the part of the rev range you use down the quarter. Remember that increasing the rev limit enables you to have shorter gears which increases your torque at the wheels throught the entire rev range.

In regards to what I think the I6 motor is capable of...

In practical terms, I think that 6500rpm is the highest you would want to go. 6200rpm is a good trade off. Remember that as you increase RPM, you will need a cam with overlap and valve timing which will reduce your dynamic compression compared with a milder cam.

For an engine that revs to 5700 rpm, I persoanlly think that a 450Nm peak is attainable. The 'Go the Mong' saloon car gets almost 500Nm (by my calculations) with a redline of 5800rpm. For an engine that revs to 6200 rpm, I think that a 430Nm peak is attainable. For an engine that revs to 6500 rpm, a 400Nm peak may be attainable.

Stav made the comment to me at the AFF Dyno Day that the BBM is a major factor in restricting the power of our engines. I think this comment has merit since the lengths of the intake tracts are tuned for around 3300rpm and around 4500rpm. Big revving motors will benefit substantially from a modified BBM or new intake manifold.

180rwkW is certainly attainable. 200rwkW is ambitious but by no means impossible.

Taking a look at your car:

Since you've got 3.7 gears already, I reckon aiming for around a 6200rpm rev limit would be the go. From here, pick your parts to give the most torque possible in the 3500-6000 rev range. Make sure your engine can breathe properly right up to 6200rpm. Have the length of your intake tracts such that wave tuning is best in the 4500-5000rpm range. [Side note: as the RPM increases, the rate of change in optimum intake length decreases] Have a cam that works best in the 3000-6000rpm range. From there, try to get the most dynamic compression possible, get the best airflow in and out of the combustion chamber possible, and get the best fuel burn possible.

I reckon your drivetrain is about as good as you can hope for which will be a great help.

For a manual AU XR, is seems to me that 180-190rwkW is what's required for a 13sec pass. A well set up car with 170rwkW may also be able to get there. As a reference, BigAl's ute made it into the 13's with 175ish rwkW.

That's what I think anyway...

i agree with the bit about the bbm,they are pretty restrictive when it comes to the high rpm stuff.

i'd have to disagree about needing 180-190rwk to run a 13.9xx.on a good day 150+ would just about get you there,160 forsure .

stiddy · 11-10-2007, 08:15 PM

Well ive got a few ideas floating around my head at the moment.
After the edit and extractors are done.
Stud girdle and light weight alloy race balancer so I can spin the thing over 7000rpm, the cam ive got now comes on strong around 3500-4000rpm and peaks at 7200rpm. Like I said its an evil evil cam.
The driveline is sorted, its just more power and how to go about it. I have it in my head what I want to do, but I was curious to see what others recommend and say.
I just know that the bottom end will pretty much remain stock, and there will be alot going into the head. About $3300 worth from a quote I got, and $1100 from the race cam I want.

**Stav** · 11-10-2007, 08:22 PM

When you're close to ready for a run at wsid let me know so I can keep you on your toes.

Btw what is the expected finish time?

stiddy · 11-10-2007, 08:39 PM

lol no idea mate, still waiting to get my car back from spraypainters, the kits still hasnt been put on yet.
When I get it back it will start happening, by xmas this year it will be back off the road with the head off it and in Perth. So it would be finished sometime next year.
Well another stage finished.

**Stav** · 11-10-2007, 08:48 PM

understand mate..its alot to do with cash as well. Food and family come before the car...heheh

**Stav** · 11-10-2007, 08:48 PM

Why couldnt I have a filthy rich uncle or something..lol

stiddy · 11-10-2007, 09:22 PM

Yeah I know what you mean, I could sink the dollars into it now, but Ive got other priorities at the moment, so as I get spare cash i'll slowly get it done.

poolkeeper · 11-10-2007, 09:26 PM

Id be going for 13s if I wasnt restricted by the rta, i got cash but nothing to buy lol.
I think its more about suspension setup and launching technique, not just a worked motor.

stiddy · 11-10-2007, 09:29 PM

Im getting rid of my suspension eventually, its on the list lol.
Will all be replaced with Whiteline gear, shocks springs, link pins, camber/caster, struts, swaybars everything all whiteline.. and polyuretherane bushes all round. I want it to handle not just be fast in a straight line.

Sapper · 11-10-2007, 10:02 PM

Quote:

Originally Posted by FS5

i'd have to disagree about needing 180-190rwk to run a 13.9xx.on a good day 150+ would just about get you there,160 forsure .

Well there's only one way to find out....

The torque spread over the top 2500rpm will have a big effect on what kind of power will be needed. This is what normally kills SOHC Falcon I6's. Just shifting the standard torque curve up 1000rpm in the rev range (would be nice if it was as easy as it sounds) would be enough to knock about half a second off the ET.

RG · 11-10-2007, 10:09 PM

Quote:

Originally Posted by FS5

i agree with the bit about the bbm,they are pretty restrictive when it comes to the high rpm stuff.

i'd have to disagree about needing 180-190rwk to run a 13.9xx.on a good day 150+ would just about get you there,160 forsure .

Ummm no, if my 347 can only do a 13.8 (albeit with a stock auto) there is no way in hell an I6 pulling about the same weight will do it with 60 less rwkw.

stiddy · 11-10-2007, 10:17 PM

Sorry to be blunt, but, Yeah your 347 isnt overly quick either. Id be asking for more than 13.8 if I spent 10k on a stroker.

RG · 12-10-2007, 10:15 AM

Quote:

Originally Posted by stiddy

Sorry to be blunt, but, Yeah your 347 isnt overly quick either. Id be asking for more than 13.8 if I spent 10k on a stroker.

Not with a stock auto you wouldn't. I still have stock heads and only a baby cam, the reason it cost what it did is because I used quality parts so when I do go silly with it later the base for it is already there.

OED666 · 12-10-2007, 10:52 AM

I am also surprised that there have been no AU's in the 13's yet. I ran my 13 second qtr over 14 months ago.

Weight wise, I dont believe AU's and ED's are that different. (i am sure ppl will disagree though).

stiddy, IMHO the clutch you have wont help. You need a clutch that you can slip off the line, and you will kill the button clutch, and also put a lot more strain on your gearbox. I wouldnt say T5Z's are bullet proof by any means.

I have to say the cam I have is excellent. After I initially get the car going at the drags, its nicely in the rev range and pulls very hard.

I havent been down the strip since I fitted the BBM, but it does feel just as good, and after I had it tuned, I did gain 10RWHP. I'm not complaining about it.

Also on the injectors. I have a fly's old fella off 170RWKW, and I have no dramas with my standard ED injectors. I am also running an XR Fuel Pressure reg as well. With my ED manifold I had my standard FPR with no fuelling problems.

I believe extractors and an edit will get you there, if you can launch it (doubts with the clutch).

AND... Street Tyres FTMFW!!!

FS5 · 12-10-2007, 03:46 PM

Quote:

Originally Posted by RedXR347

Ummm no, if my 347 can only do a 13.8 (albeit with a stock auto) there is no way in hell an I6 pulling about the same weight will do it with 60 less rwkw.

tripowers au only had 150rwk and he's the quickest so far.

Mark351 · 12-10-2007, 04:36 PM

Quote:

Originally Posted by stiddy

Im getting rid of my suspension eventually, its on the list lol.
Will all be replaced with Whiteline gear, shocks springs, link pins, camber/caster, struts, swaybars everything all whiteline.. and polyuretherane bushes all round. I want it to handle not just be fast in a straight line.

A road handling car != good handling car for the strip. I think my XR6 is a good example of that, in fact it'd probably be a better track car with better brakes than a drag car.

For drags, 90/10 front shocks, take front sway bar out, all the usual tricks. But you've spoken to guys like Chris @ Bluepower and Craig @ ACE before - guys who are experienced drag racers not street meet hacks like ourselves. The best advice is from them.

GSH · 13-10-2007, 06:43 AM

Quote:

Originally Posted by stiddy

Im about to get my car back finally after long awaited exterior/bling mods on my XR6 and looking to start some real performance mods. As some of you know I had a turbo kit that I got rid of for my own reasons so now, I want to get a move on with some NA mods. I’ve got the wild cam and exhaust. Extractors and edit will be in the car by the end of the year.
What I want to know is if I get the engine done what sort of ET can the AU I6 realistically get without being undrivable? At the moment I’m getting 14.9’s basically stock. What’s the AU I6 got in it? Seems the best so far is a 14.2 and a claimed but not proven 13.9. Which honestly is fairly pathetic. Is that it? Is that the best an AU I6 can go NA?

Mods when I ran 14.9:
3inch highflow cat, 3inch mandrel bent exhaust with 1 small sports muffler, 3inch mandrel bent intake from throttle-body to pod in airbox.

Mods since last at the track:
Rebuild/strengthed T5, 5 puck brass button clutch and billet alloy lightened flywheel, 3.7 diff gears 4 pinion LSD center and billet axles, a bloody wild surecam and Fusion Speakers lol. Also Kingsprings and Koni shocks.

Mods to waiting:
Difillipo extractors with 3inch collector, Edit with custom tune, a Ripshift shifter and some sticky tyres.

Cheers,
Stiddy

My car (check my signature) i pulled a 15.0 with a fair wack of wheel spin and its auto. So 14.9 is impressive time for a 6! All my mates are like 6`s suck but they no nothing. 6`s have alot of potential. If you really wanted to you could do 13`s. Its all about $$$$. Just like everything else in life