How'd I do?
 

I strapped the car down for the first time on the dyno this past Friday night. Made 496hp @ 6166rpm with 437tq @ 5729rpm all motor. 396 lt1, 4L80E, 3400 stall, 9" w/4.30s on a Mustang dyno. :) will be back in the near future for N2O tuning. Proof pics to come...

Very impressive!! Should be a 9 sec car with that kind of power through a 4L80e on a mustang dyno. The torque numbers seem a bit weird being that you made peak horsepower at only 6200 rpms but peak torque at 5700 rpms. I would think making peak torque that high the motor would peak closer to 7500 rpms. I am surprised your torque does not peak around 4800 rpms with that setup with a number closer to 520.

What heads, cam and intake are your running? Compression? Race weight?

Your car should roll out.

Heads I think are a limiting factor for me. They are AFR 195 castings that have been machined by Lloyd Elliott to a 214cc runner. Cam is 255/263 .688/.688 107lsa and a ported Edelbrock lt1. 12.3:1 CR. Not sure of weight yet, we were going to scale it the other night but didn't due to time constraints. We inputted it at 3800# with driver but I know its less than that as its a hardtop no power options car and deleted A/C and I'm 180#.

Those heads should be fine for that setup to 7500. You might wwant to look into the valve springs on why you didn't peak higher for horsepower.
My heads are a little bigger than yours (prob around 225 after the hand porting) and they are plenty for my 383.

What did the dyno graphs look like?

If you removed the AC you should be ~3450 stock weight with 1/2 tank gas. So add 180 and you should be at 3630 race weight.

https://cimg6.ibsrv.net/gimg/ls1tech...36b8d27e7f.jpg

https://cimg6.ibsrv.net/gimg/ls1tech...a9e9e01c8c.jpg

Looks good! Now I see why your torque numbers are down. The graph starts at 5500 rpm...lol. I bet the car makes 500+ ft lbs at a lower rpm. I am still surprised the power drops off that quickly at 6600. That cam and compression should let you carry those numbers past 7k. What valve springs are you running? Comp 943's?

What fuel are you running?
How does the car feel to you?

The springs are 943's. I'm running 93 on the motor. As far as how it feels, I have no good answer for that. This is my first stalled auto and have minimal street time in it and no track passes.

Another quick thought...ideas on timing baseline where the lt1 likes to run? It is tuned at 30* right now because that's kinda the neighborhood SBC motors like to be but everyone is so familiar with FI LS motors now-a-days and they like the mid 20s range...

Your springs are good. What exhaust are your running (headers, y-pipe, and cat back)? Still running the stock pcm and knock sensors? I am surprised you are running 93 and not having any detonation. What is your quench and dynamic compression or if you have a cam card your intake valve closing after BDC?

Our combos are very similar except for 383 vs 396, 12.1 vs 12.3, single plane vs ported stock, and cam 259 267 108 lsa ~.650 lift accounting for lash, and I am running a 5500 8" stall. I am hesitant to run pump gas on my setup as my tuner says he would not risk it with 12-1 and my cam at 9.3-1 compression. I am curious what were your tuner's thoughts on the pump gas?

My timing is at 34-36 degrees at WOT depending on load 95kpa-105kpa. You will need more advance as rpm increases due to the length of time the mixture has to burn at higher rpm but every combo is different. I would be careful advancing timing on pump gas.

Headers are Pacesetter longtubes, 1 3/4 primaries to 3" collector to a y-pipe, and that run was out through a 3" cutout. It is 24x converted so a 0411 pcm and a single knock sensor. quench is .028". I have never figured my dynamic CR and don't have my cam card handy. What degree of timing are you tuned to? What are your hp/tq numbers?

My setup does not have any rwhp dyno numbers as it prob wouldn't make much sense with a th400 non lockup and 5500 8" converter. If I were to guess, I would say somewhere around 450rwhp. I do not have track times yet as I am waiting for the weather to break to get some comfortable air (no AC and no car trailer so I have to drive 40 minutes to my local track). I am running 1 7/8" 3.5" collectors Hedman headers as I will be running a 150-250 single plate setup (It is on the car but just not wired in yet as I need to dial in the N/A tune and setup before adding in more power). I would guess the car is ~10.7-10.8@126-128mph as it sits based upon some of the street runs I have had with the new setup. I am tuned to 28 degrees at 2000 rpms and goes up to 34-35 degrees up to 7500. I am at 25 degrees at idle. You are running a pretty tight quench which is good for pump gas. I am at .033 quench so our setups are very similar. I have a .027 head gasket with a 4.060 bore and my piston is .006 in the hole with 58cc combustion chambers that net me 12.15-1 compression.

How are you running knock sensors with the solid roller lifters? Are you getting any false knock? Any knock at all?

Awesome numbers, can't wait to see track times, good job! Do you have a picture of the whole graph, like 4000 rpm on? The torque is crazy how it stays that high for that long!

I don't have a printout of the full run. We were zeroing in on that range in particular because that's where we were smoothing out the AFR. I'll get a full graph when I go back for the N2O pulls.

Right now I am on one knock sensor, and it doesn't seem to be reporting anything at all. Now, is that because there's nothing to see? Is that because its not working? I'm not sure. But I have a new one at home that I'm going to put in just as soon as I feel like taking a coolant bath, lol. I still feel fairly safe without it as my fueling isn't aggressive, timing doesn't seem aggressive, and I'm 93 on motor and spraying 116 from a standalone with the nitrous.