new head /retune results

got the retune done on our au i6 today and the results are a tad different to what i expected
with the original head it made
159.2 rwk @ 5400 and 321 nm @3800
now after fitting the new head
156.7 rwk @ 4900 and 348 nm @3200
can't wait to get a bigger cam
c and j did the tune both times and are great guys to deal with .

going buy the seat of your pance feel, it feels a lot stronger than before . definatly feels quicker.can't wait to get it back out to willow bank for a run.

in case your interested the head flowed around 368 hp @ 500 thou and had 12 thou knocked off it just to sraighten it up.

i'll get nik to post the graphs up later .
by the way i'll be selling my original head too ,if anyone is interested,will be posting it up in the 4sale section later
catch ya jake

[jonbays]

Not what I would expect of a ported polished flow tested head either.

With more flow you have less power at lower rpm. More torque at lower rpm sounds right and is backed up by the seat of pants comments.

Why wouldn't more flow give more power for longer in the upper rev range?

[Stav]

Jake I like you mate but we all have to face a terrible truth..dynos are inconstent.

i'm definatly not disapointed with the results .the car had both tunes done on the same dyno by the same guys .i reckon my original head was better suited to the cam .
when nik posts the graphs you'l see . the new head has picked up heaps more hp lower down the rev range .acording to the graphs @ 3000 rpm i used to make 96 rwk and 300 nm and now i make 110 rwk and 345 nm it's brought the whole power curve backwards. it feels more like an 8 than a six.
the track will tell though i'm gunna have to learn how to launch it all over again .least it's gunna be fun trying.

[xr8ute]

Thats a pretty impressive increase in torque down low. Looks like it is time for a bigger cam to shift that torque curve up a bit so you can make more power.

What cam is in there now?

Do you have flow figures at other lifts or just 0.500"?

[parawolf]

Originally Posted by jonbays

Not what I would expect of a ported polished flow tested head either.

With more flow you have less power at lower rpm. More torque at lower rpm sounds right and is backed up by the seat of pants comments.

Why wouldn't more flow give more power for longer in the upper rev range?

Could be leaning out now that it is getting more air at higher rpm...

[jonbays]

Originally Posted by parawolf

Could be leaning out now that it is getting more air at higher rpm...

yes that makes sense.

The JMM Dev kits work on the fact the dodgy rich as buggery stock ecu program works well with the right cam and more flow but more flow could cause it to lean out as its pressure drop MAP sensing.

Originally Posted by xr8ute

Thats a pretty impressive increase in torque down low. Looks like it is time for a bigger cam to shift that torque curve up a bit so you can make more power.

What cam is in there now?

Do you have flow figures at other lifts or just 0.500"?

yeah i'm all for a bigger cam .
it's currently running a jmm streetfighter cam .
i have the complete flo figures for the head .as soon as nik gets time i will get her to post it all up ..


the injectors weren't maxing out according to c&j so i don't reckon it's leaning out.

[Stav]

Yes this is awesome news mate.The head has worked a treat .Whoever did the job has maxed your low down power and now youll be flying...they know their stuff ..btw get bigger brakes!!

* this is Nik*
Ok so I got off my *** and doing this for Hubby. Here are the pics he said to put up

[Stav]

Jake and Nik the torque is looking really good.How much did the head cost if I may...?

[LG]

It's not that bad with the same cam. Your pretty much making the exact same power but at a lower rpm. And your making more torque at a lower rpm as well.

What was your old head? What are the specs of it, and how much? And also to follow useless's post, what head are you running now, and how much? Are you using a Streetfighter head, with a bit of custom work or what?

Thanks! Good job!

the head that's on there now is an au series 1 i got from te wreckers .
it cost $960 to get it ported and tidyed up with new valve guides.
my old head was just the standard series 2 .

[jonbays]

Interesting to see the two dyno charts.

I have to agree with useless on this dyno's lie.

I always worry when I see dyno charts with huge differences in the AT, IT and CK figures It looks dodgy. I doubt it a valid comparison.

Put it on the strip and see what real world difference there is in the terminal speeds on your old and new slips. This will be much more telling about more overall power.

[Stav]

This may be too little too late..but I think the cam may be over advanced?

[Sleeperau]

[about to get a tune for unichip plus a good cam dialed in Where do you sugest in bne. I will have the high stall & diff by March as well. .... 14's here will come . Hope you can help the sleepermobile to disgrace the V8 Holdens? :

[Sleeperau]

Originally Posted by jonbays

Interesting to see the two dyno charts.

I have to agree with useless on this dyno's lie.

I always worry when I see dyno charts with huge differences in the AT, IT and CK figures It looks dodgy. I doubt it a valid comparison.

Put it on the strip and see what real world difference there is in the terminal speeds on your old and new slips. This will be much more telling about more overall power.

Jonbays , that was obvious in 1/4 times between u & Usless

[Stav]

Originally Posted by Sleeperau

[about to get a tune for unichip plus a good cam dialed in Where do you sugest in bne. I will have the high stall & diff by March as well. .... 14's here will come . Hope you can help the sleepermobile to disgrace the V8 Holdens? :

I dont know mate. A good tune will work wonders.As for dialling a cam ...I am seeing that most mechanics dont have a clue.Thank god for this forum.
For the chip retune I know nik uses cnj motorsport.

Originally Posted by Sleeperau

[about to get a tune for unichip plus a good cam dialed in Where do you sugest in bne. I will have the high stall & diff by March as well. .... 14's here will come . Hope you can help the sleepermobile to disgrace the V8 Holdens? :

i'd go c&j for the tune,i will be selling my streetfighter cam in a week or so if your interested .it disgraced a few holden / ford v8's.

[jonbays]

Originally Posted by Sleeperau

Jonbays , that was obvious in 1/4 times between u & Usless

My best time for the day was the following:
R/T 60' 330' 660' MPH 1000' ET MPH
0.2040 2.344 6.570 10.009 71.45 12.963 15.464 90.24
versus Useless
R/T 60' 330' 660' MPH 1000' ET MPH
0.707 2.177 6.327 9.746 71.82 12.697 15.194 90.10

Given we both have AU wagons and the weights are similar and the terminal speeds are close I would say the Hi stall converter and 3.7 gears are what gives useless dev4 the edge on the track.

[jabba]

Hey Nik... The shop is not called C and J motorsport. It is CNJ motorsport.. I thought I would clarifie that, just in case someone wanted to use them.

[Stav]

Originally Posted by jonbays

My best time for the day was the following:
R/T 60' 330' 660' MPH 1000' ET MPH
0.2040 2.344 6.570 10.009 71.45 12.963 15.464 90.24
versus Useless
R/T 60' 330' 660' MPH 1000' ET MPH
0.707 2.177 6.327 9.746 71.82 12.697 15.194 90.10

Given we both have AU wagons and the weights are similar and the terminal speeds are close I would say the Hi stall converter and 3.7 gears are what gives useless dev4 the edge on the track.

absolutely :

[Sleeperau]

Originally Posted by Nik

i'd go c&j for the tune,i will be selling my streetfighter cam in a week or so if your interested .it disgraced a few holden / ford v8's.

Let me know Nick, that could be a good option.