SprayedLT1

iTrader: (8)

I finally got around to getting my LE3 heads and LE ported intake on the car a few weeks ago, and had it dyno tuned yesterday. I had Ion from Madtuner do the tuning. I'm not really excited about the results, and wanted to see what you all thought.

For comparison, I'm also attaching my dyno from before the head and intake swap, when I was "cam only" and made 332/348. After the swap and tuning (nothing else changed but heads and intake), I made 362/329. Converter was unlocked both times car was dynoed, but the numbers just seem pretty low to me, I was expecting more then 30 rwhp after the head and intake swap.

Major mods are: 355, forged flat tops (-5cc), stock bottom end, LE3 heads, LE ported intake, COMP 280XFI cam (230/236, .576/570 113lsa), 52mm tb, Yank SS3600, FLT Stage IV 4L60E, Moser 9", Jet Hot long tubes/true duals with bullets.

The dyno operator said my torque converter is way too loose now and was flashing up to 4700 rpm, so we were not able to tune it for nitrous. I called Dave at Yank about getting the converter re-stalled, and he wants me to do a few things to check the stall speed before going forward. He said that stall speed on a dyno was not reliable info.

96capricemgr

iTrader: (1)

It looks like the cam only graph is uploaded as the .jpg and you seem to be treating the spike as real numbers.
The .pdf is the heads/cam setup.

Why did they stop the run so low in the rpm range? Big set of heads like that and a cam that large I would expect more rpm.
The graph is a hassle to look at with it zoomed to just a high HP range and the TQ and HP being on different scales. Being zoomed in like that makes the variations in power look a lot bigger than they are.

SprayedLT1

iTrader: (8)

True, I didn't take into consideration the spike, though the hp numbers appear to be accuate as only the tq has spikes. Let's pretend the spikes aren't there in the torque curve, it would be around 320 lbft...I gained only ~10 ft lbs of torque with the head and intake swap? I'm not sure why he stopped the pulls at 6k, I told him to go to 6200.

I guess my question is this... I see the average LE2/LE3 car make around 400 rwhp, but are thos 6 speed cars with 10 bolts? I know my stalled auto/9" uses more power, but I was expecting a little more out of the combo.

355z28

iTrader: (8)

Get it to the track first before you say your not happy.

My LE2 383 made 388/381 on the dyno. My converter wouldnt lock up and was flashing pretty high. After hitting the track it ran a best of 11.28 at 3700lbs. DA is in my sig. Pretty pathetic dyno numbers but the car gets down and moves for what it is.

95mysticta

iTrader: (4)

Isnt that cam supposed to pull to 65-67? I think you need to figure out why its spiking and then make sure the guy running the dyno makes a full pull to make those heads work.

SprayedLT1

iTrader: (8)

Very true

speed_demon24

iTrader: (6)

To get the most out of that cam you'll probably want to be shifting around 7k with a good set of heads. I would expect peak power around 6500.

SprayedLT1

iTrader: (8)

Comp rates it to 6k, but it was clearly still making power at 6k. It was only spiking on the cam only pulls, though there was a dip on the pulls yesterday around 5800-5900, then it starts pulling again. I'm thinking opti.

RamAir95TA

iTrader: (2)

Are you sure they are LE heads? Did you buy them used?

SprayedLT1

iTrader: (8)

I'm pretty confident they are, I bought them from Clint, T/ALT1. Now that I think about it, I KNOW they are because I talked to Lloyd about those heads and intake and he remembers doing them for Clint.

gregrob

iTrader: (8)

I'm proud to see the AI guys helping out instead of bashing.

I would pull it to a higher RPM as stated, and TAKE IT TO THE TRACK!

Racing dynos gets you nowhere. None of the fast guys do it. Don't worry about what it makes, until you get it to the track and see what it traps, and ETs

SS RRR

iTrader: (2)

As everyone has said, take it to the track. Big converter dyno numbers are always wonky.
That hasn't happened in months.

96capricemgr

iTrader: (1)

Comp's numbers are wrong, they seem to be based on old dual plane gen 1 intakes, LT1 intake being very differnt plus LT1 heads being better shifts the rpm range upward substantially.

Hell the stock b-body cam is worth turning 5800rpm or so and it is 191/195 .418/.430 111

Far as jumping to the opti assumption like I said variations are not that big, it just looks like it because the graph is showing a narrow range on the HP graph.

whytryz28

iTrader: (28)

Put in the stock 10 bolt and small TC and you will see a good dyno run.

robsquikz28

iTrader: (246)

I have seen many 383s get under 400hp and make what u did. It's fairly common. But none the less dyno is for tune only. So track that car and the real numbers will be surprising.

96capricemgr

iTrader: (1)

The Yank converters work pretty well, while I do agree many converters can show a lot of loss most of the guys doing careful analysis of Yank's performance find them to be highly efficient. Sure it will show some loss but it should not be the scapegoat here.

Run it, see what it does before you get caught up in the excuses guys are trying to give you.

Nostang

iTrader: (4)

FWIW, I dynoed my car after I ran an 11.4@118 with a 1.579 60 ft @ 3650 raceweight and it only made 355rwhp and 360rwtq. This was a 11.5 355lt1 with gtp lt4 stage 2 ported heads and intake, 236 242 112lsa cam with a th400, 9" rear with a nitrous converter.

Like the other guys said, don't be upset until you run it. I would have figured a 35-40rwhp gain at most from just a head and intake swap while leaving everything else the same. Now if you put in a much bigger cam you could expect 60-80rwhp depending on how radical you go with the cam.

moehorsepower

iTrader: (3)

Yup, One customer had a bottom of the page cam, Heads with huge runners and a 4500 stall, made in the neighborhood of 330 RWHP, Man I thought either he was going to cry or go postal, anyway at at the track he ran 10.90's...He was happy after that..

Puck

iTrader: (17)

If you just wanna see a number you can lock the stall and spin higher.

Personally I wouldn't worry about it unless it doesn't perform at the track.

Rob94hawk

iTrader: (1)

Sometimes it's all some of us have since there are no tracks anywhere near me. But I hope the OP has one nearby.

Does it feel like it has the power you expect? My butt-o-meter isn't accurate but after my build I knew that this thing had some pretty damn good power.