347 dyno results

[smh00n]

After many a month, I finally stuck my car on the chassis dyno yesterday.

I have to give a massive shout out to @shaunp as he answered all sorts of dumb questions, gave me advice and basically held my hand for the engine build.
The specs are
USA 8.2" roller block
Scat cast crank
H beam scat steel rods
SRS forged pistons about 10.5:1
Dart Pro 1 heads - 2.02"/1.60", 58cc chambers and 195cc ports
Lunati voodoo cam - @ .050 (Int/Exh): 231/239
RPM Airgap manifold
Sniper
1 5/8" long tube headers - bought from Ford Power Applications in the US, these replaced a shorty set that didn't clear the Borgeson box. Not cheap at around $2,200 but they give it massive torque and clearance (they don't hang under the rails). Do yourself a favour and buy them.

Whilst I got the machine work done by a shop (and got bent over in the process) I bolted it together myself. I used ARP studs through the main and heads (simply because I could), fitted a windage tray and crank scraper, baffled Boss sump, high volume oil pump and MSD ignition.

Holley claim the Sniper to be 'self tuning'. Don't get sucked in, it learns fuel and is excellent for a stock lump, but as soon as you put demands on the fuel and ignition you are straight to custom build territory. And I am not a fuel or ignition mapper.
After months of phucking around with forums, remote tune files and BS, I took it off to http://unigroup.com.au/unigroup engineering to be tuned and mapped.

And this is the result. I was never chasing power on this build and all I wanted was to be able to scare the kids with no suspension in their jappers. This thing will bag up the rears all through second gear (a TKO600) with 3.55's but will also chug around corners in 3rd gear, so happy with the result.

[Edz66Vert]

Love the gear in that motor, top shelf which is nice.

That looks like good hp, I assume at the rear wheels? Can you post a full pic so we can see rpm and torque under the curve?

This is my old engine graph before the rebuild. I was about to get a dyno but roller rockers are dying.

[hybrid]

That's good power for a light car like ours. Sounds like it drives nice too, which is what you want.


This was my 347 session (with blower though) when we could only rev to 5500 when the gearbox started slipping. Torque was still climbing there, so hoping for some more out of it next time around with the bigger engine revving to 6500 or so.



You're absolutely right about the self tuning units. They will definitely get the car going, but don't expect to get the most out of it. Or much more than carb/distributor unless it was originally tuned pretty badly.

Did you end up starting with the ignition table I sent through?

[smh00n]

It was run on a chassis dyno. I dunno how to upload a video directly here. Hybrid....???????
The man tells me he expects a 20% loss so maybe 420 at the crank? Dunno if that's regular or bragging rights power.

@hybrid I did look at your table and it was close to what I was working to and did help, but after stuffing around for a few times I just thought it BS to have an amateur like me trying to fix it, so I just booked it with Unigroup. Not cheap, $1,350 but 4 hours later it is much better.

This is the graph of the last run. He managed to fatten up the midrange around 4,500 from a bit of a dip to a nice curve. I also think he was a bit timid on the gas and let off before the hard cut at 6,500.
Everybody who didn't pay for the lump said it would be good for 7,000-7,500 but I elected to go home with a non-ventilated block so put the hard cut at 6,500.

He did 8 runs, picked up 30 horses from first to last but also massively improved the start and idle and bought a bit more driveability into it.
One trick thing he did was to delay the actual start/firing for about 4 cranks so it gets oil through first. I thought it was pretty neat how it used to fire up on the first turn but thinking about it not real good for the rotating bits.

The only issue I have with the thing, apart from the fact I sold a brand new 650DP at a loss to spend close to $4,000 in total putting this Sniper on, is that at take off it drops a shit load of timing and basically stumbles firing one hole at a time until you put some gas into it. Unigroup man said it was the cam, which is partially true but I really don't want to have 1,500 revs on board to slide casually out of a parking spot. Not to mention the clutch life.
I have boosted the timing under 900rpm from 12°to 16° to see if that improves it. Not yet driven it but I am hoping it will rectify it.

[hybrid]

Just upload the video to youtube - set it so that only people with the link can view it, then post it here.

[smh00n]

[hybrid]

Just put the video ID from the end of the URL rather than the whole URL, so just vFaqgixOYOs
I've fixed it for you.

[smh00n]

Thanks. Too techno for this fummy