Hi Guys,

I'm new to the site and this is my first post.It looks to be an awsome site with tons of info And helpful people.

I am in Australia and am building an injected 496 for my 1979 Holden one tonner which is a GM cab chassis ute.
The motor is a 4bolt block with Eagle forged rotating assembly, AFR 325 heads with cnc chambers And Lunati 60234 solid roller. The comp is 11-1.
The ecu is a vipec v-88 and am planing on running a victor jr and Edelbrock 1000 cfm throttle body. I haven't bought the intake yet and i am seeking opinions on this.
Has any one had experience with uneven air flow distribution with this intake? Are there better options?
If i run it as sequential i am pretty sure i can trim individual pots but you need to know which ones are rich or lean.
which leeds to my next question is it worth setting up sequential over batch fire apart from the ability to trim individual pots? to run sequential i would require a cam angle sensor as well as crank trigger. is it worth the extra hassle?
On the ignition side Should i run a distributor and single coil or I have eight ls2 coils i could use but would require more wiring and then mounting the coils some where. Would there be any advantage to running individual coils? The motor should run to 6800 i guess an make 650+ fwhp i hope.
Your opinions would be much appreciated.

Cheers, Al.

hi Al
welcome to the site
sounds like an interesting ute project
what does it look like?

Hi Vince, thanks for the welcome, here is a pic as i bought it but it now has 15" rally wheels instead of the daggy 17" wheels.


http://i815.photobucket.com/albums/zz80/al510photos/hztonnerpic.jpg

bizzaro..........
different.
some cool cool stuff in the background

Cool deal there.

I'd forget the sequential deal. You'll spend a lot of money and get very little return. In order to make any meaningful progress with it you'll need to run 8 O2 sensors and do a lot of datalogging.

Most of the modern manifold/throttle body setups will do pretty good especially at WOT where it really counts. For part throttle perfection you'd want to run a tall manifold with a plenum and long runners and a divorced throttle body. Basically, move the TB away from the runners so the angle of the the butterflies doesn't shunt air to one part of the manifold or another.

You'll spend a lot of money chasing the last 2% of performance here.

New Holley computer setups are pretty good, easy to work with and lots of options.

Hi Guys, Thanks for the comments,

Tom, I already have this ECU http://www.vi-pec.com/page_files/V88.html which can control sequential injection. aside from the difficulty in tuning individual pots do you think there would be any benefits to part throttle drivability with sequential over batch. the only extra cost to do this would be a cam angle sensor and some wiring. if i run the individual coils i would need the cam angle sensor also.

Cheers, Al.

truthfully I doubt you'd notice any improvement. most reports seem to be real happy about reduced emissions at idle. I think you'd get more out of 8 coils. Those things deliver a real jolt.

IMO, this deal is still really a vendors paradise, all kinds of claims about fantastic performance improvements, huge fuel economy gains, etc. I've known a couple guys who went to lot of effort to set up the seq deal, were disappointed except for bragging rights gains.

Al,
I hope you stayed high and dry in the floods last month...
When I had a Motec M800 controlled motor on Craig Hasted's Superflow 901 engine dyno in Browns Plains, southern suburbs in Brisbane, I didn't want to destroy my own headers to fit 8 x O2 sensors or temp sensors. It was a 351W and we did it by reading the spark plugs. This won't have fully exploited the performance potential of a sequential ECU, but it made the ratios right for my 800+ hp blown small block with a Super Victor 4 barrel manifold.

Having said that, I'd bet money that he - and many other dyno guys - has a set of BBC "dyno pipes" that already have the O2 sensor bungs in them. I'm going to have the big block in my Chevelle dyno'd with an M48 Motec computer soon, and I'll be tuning it as a proper sequential deal.

You have to think some of these things through a bit...

A) What is the injector duty cycle?
B) What is the intake duty cycle?

When "A" meets or exceeds "B" then sequential loses any advantage.

Where sequential may offer some improvement is when injector pulse width is low and you can synchronize the fuel pulse with the air flow pulse to get a cleaner cylinder fill. Based on valve timing overlap you can get some air flow out exhaust and/or intake. If you time injection to minimize fuel in that "leakage" air you can gain some efficiency.

Another area where sequential can offer benefit is in optimizing each cylinder individually to compensate for air flow variations. Frankly $$$ spent here could be more effectively be spent on a decent intake that flows more evenly instead ;)

IMHO at cruise speed you likely have enough air moving through that sequential won't provide any noticeable difference.

Hi Craig,

good to see another Aussie on here. we were fine with the floods, i hope you were too.
That is a great looking car you have there, i think the chevelles are one of the best looking looking cars out there.
Did you have to change the mixtures much based on the plug readings or were they pretty close? It will be very interesting to see how you go with your new set up.

Hi Steve,

I understand your comments about injector pulse width affecting sequential injection but i thought the biggest gains would be in drivability at part throttle and cruise conditions when it would be no where near 50 % duty cycle. the idea of injecting fuel avoiding the valve overlap window is interesting and i could see some benefit there for economy.
As for the intake that was my main point of interest in this thread. Do you have any suggestions as to what would be a better manifold for my application or is it something that would need lots of dyno time and multiple intakes to try?

Cheers, Al.

Al,

My thoughts on intake run more towards maximizing torque rather than HP. I prefer long individual runners and larger plenums on EFI intakes. There are NO currently available EFI intakes for BBC that entirely meet my criteria :( (at least that I am aware of ;) )

The GM RamJet and new Edelbrock are about the closest. But I would like to see something more like the LS1 intake.

I have an older Accel DFI intake setup at home that someday I might even install. It consists of basically a tunnel ram base without the carb plenums. On top of that is a box plenum with tubular individual runner extensions inside. It comes close to my concept but is height challenged (i.e. it is a bit on the tall side).

Many of the EFI setups on the market use what is basically an intake designed for a carb with holes drilled for injectors. Problems include uneven airflow distribution, inadequate plenum volume, and airflow disruption from throttle blades interacting with the small plenum and the forced changes in airflow direction. For this type of intake I prefer the single plane design but that tradesoff larger effective plenum for shorter runner length.

How do you think the holley 9901-201 would compare to the Vic jr for my application?

Cheers, Al.