I was a little dissapointed. It's a long story but I will explain later.
The printer at the dyno place was broken so they had to email me all the files, but now I can't seem to get the HP and torque curve on the same chart without getting a "floating point error"
I know someone will ask it so was 460rwhp/460rwtq but I can only get HP, RPM, AF on the graph,but when I try to add torque, I get a "floating point error" and its driving me nuts.

matt
more tonight

Matt,sounds like very good #'s to me :cool: graemlins/thumbsup.gif
when you going to the track? I'm hoping to get there this Saturday for test and tune..

I think the numbers are good and accurate too. You dynoed at 565 hp at the crank, and 460 to the wheels. Thats a 19% loss. Since the accessories and exhaust were the same for each dyno, the drivetrain loss is right around 20% as the rule of thumb predicts. I would be happy in your shoes.

What brand dyno was it? I'm really surprised how much difference there is from one dyno to another.

Your ride showed 460 rwhp to run 12.09 @ 4000 lbs, yet my ride only made 418 rwhp to run 10.66 @ 3600 lbs (mine was on a Mustang dyno). One things for sure, you can't even consider comparing hp/tw numbers from one dyno to another.

Did you tune the car on the dyno, or were you simply looking for a power/tq number?

Ok..

There are some problems that haven't been resolved with the dyno numbers. The guy at the shop who ran the computer for my car wasn't the owner of the shop. His two programs for data analysis did not give the same torque readings for my engine. However, his printer was broken, and he could not print me any of the sheets. He asked if I had email and I said 'sure' and he emailed me the dyno runs and told me dynojet offers their software on their website for free to view the dyno runs. The software they offer is the new software and shows a lower torque number by a considerable amount, but he couldn't get the old version to print anything but todays date (or a reason why it did this, but he told me the bigger tq # was the right one...?). But its just a number. I will work this out eventually. I cannot fathom why this would be, and it is not just the types of correction factors you can pick.
I am still very worried about the governor and where it shifts, I was unable to tell on the dyno when I tried to test it because it happened to quick. I haven't gotten shifting the staple by hand down yet. I had never rev limited my hydraulic cammed motor, this thing has hit 6500 (6600 rev limiter) 4 times already. I should really find my 6400 chip and put it in there, I was told 6200 is all the engine needs to see. I don't think 6600 will nuke it though. (ramble..)
Unfortunatley, they only offer the new version of the software which shows me torque numbers as being off quite a bit (25%) from the engine dyno-- which is not unheard of. However, the engine dyno session was done as "realistic" as possible.. 88* room temp, my headers, my x pipe, my mufflers, my tail pipe, my alt, my water pump, regular timing, regular operating temp, 300rpm/sec upward dyno run. I'd expect that to be worth atleast 5-10%. So I think things are a little off here. A 30-35% loss I just don't buy, period. I think the percentile loss theory is too general as it is, never mind 1/3 of an engines power.
And my cam swap guy (I called him when I got home) said "something is seriously missing because he has done a number of 454's with turbo 400's that have made less power than me overall but made much much closer (within 50hp he said) of their engine dyno #'s at his shop). He said something isn't adding up, and suggested maybe the gear vendors could be eating alot, but he said that is probably not even enough to account for such a large loss. I know 15-25% loss is relatively normal for a conventional setup, but 25% loss for how he ran the engine dyno is.
Its plenty fun to drive and I will be happy to find the extra power if it really exists. Before going to the dragway, I need to do the following: replace the rear springs with my old ones, raise the front of the car whatever the rear goes up, adjust the engine mount so the headers do not bang the steering column as they do all the sudden, install my fixed torque converter, and install my new speedo gear and case (long story), reattach the vacuum advance, and maybe a couple other things. Then I may drive to LVD instead of trailer since I won't be using slicks/ET streets/drag radials. The car is a pleasure to drive, I love the feel of the solid and how smooth it is, and I like how quiet the car is now. And man you have to pay attention to that tach! the revs take off like nothing else!

Sorry for the long post, I know I turn everything into a saga. But-- I think once I get the above worked out, the car will be reliable, quick, and fun to drive- which is what I really always wanted. Hopefully the replaced converter will make it alot easier on the trans/rear/my neck to drive. Sorry for the post-- I had a heck of a day today.

below is a link to my 4 dyno runs today, these were done with a 12" stock converter. Large picture 209k-- sorry folks. I have been very busy today, and I do know how to resize now I just didn't bother.
www.detroit-iron.com/images/combodyno.jpg (http://www.detroit-iron.com/images/combodyno.jpg) (~200k)
I disconnected the electric kickdown after trying to test the governors shift rpm. BTW: say the chassis dyno #'s are perfect and nothing is wrong as SDCE says, whats 450rwhp/430rwtq worth in a 4020lb 3.90 TH400 car, MPH wise?

I hope to hit LVD this month, if not saturday may 15th. Then super chevy is coming up, I will be there that saturday only unfortunately).

this part is optional to read, (as is anything above)
I get some questions about my combo and since my website isn't ready yet I'll just detail it real quick:

454 +.032
perf RPM rect port intake, lifter valley splash shield
dart 320 rect port heads, 116.5cc chambers
crower 1.75 roller rockers
CR lift rule 287/291 256/260 .643 112LS solid roller
isky red zones
comp 933 springs
(I love the solid feel, but worth it, I don't know..)
decent pushrods
decent valves
holley 4776 DP upper, with 4779 baseplate (750/850)
10.14:1 SRP forged slugs
stock gm 4.00 forged crank
2 bolt LS5 block
TH400 with 9.5" 3400 stall converter (next week or so anyway)
12 bolt 3.90s
p315/35R17 radials rear

to put it mildly, if I reframed it as the matching # LS5 454 it is, it wouldn't sell for what I put into it at barrett-jackson-- and its not something I'm proud of,but live and learn. there are some pics of the car in my showroom on TC (whatever the link is) and a pretty pathetic dyno vid on the website which I am working on.

matt (I promise to be quiet now).

To answer some mid level questions, I am happy with the power, its just not what I was expected. (+25hp from a mild hyd roller to a solid roller..?) It was a dynojet 248c?? I think. My car weighs 4020lbs with me and 1/3 tank of gas. Add 10-15 more gallons and you're looking at about 4100lbs. Its a tank.

Also 10secBU the 12.09 was the old hydraulic cam on 26" tall ET streets. Next time I hit the track its gonna be on my p315 regular radials.
Also, the car was tuned on the engine dyno, and with the exception of the quick rise and dip on one dyno pull because I goofed with the tranny on the chassis dyno, I think the AF ratio looks dead on for a carb.
matt.

You said it made 460 rwhp and 460 rwtq and that's right in line with your 565 flywheel HP as noted above. 19% is very reasonable. I actually called Scott after you and I talked last and told him there was no way a 560 flywheel HP setup would make 520 rwhp like he predicted. I scolded him for doing that to you as you would undoubtably be disappointed! ;)

Bottom line, chassis dyno numbers are fine, but how it runs on the street and track is the real test. It sounds like you're happy with the way it runs and feels, just not happy with the numbers. Don't get too caught up in the numbers; how it runs is where it's at.

Just as an aside, my 12.5:1 468 with fully-ported Canfields and nice solid roller only made 485 rwhp, but it did make 600 rwtq. I too was disappointed in the HP numbers, but it sure ran good!

Jody

Originally posted by camcojb:
It sounds like you're happy with the way it runs and feels, just not happy with the numbers. Don't get too caught up in the numbers; how it runs is where it's atThats what I say! Just enjoy it and don't pay attention to the numbers,unless they're attached to a timeslip graemlins/thumbsup.gif

dynojets are inertia dynos and they read quite a bit higher than mustang dynos I understand - like 10%-15% higher.

blah, blah, blah. Just line it up and run it down the dragstrip - best dyno known. Making power is one thing - getting is efficiently to the ground is a whole different matter.

Something that should always be looked at when an automatic trans car is on the chassis dyno: slip percentage, just compare theoretical no slip rpm for a given mph against the actual rpm vs dyno road speed. Many people have been let down by a transmission with too little pressure (internal leakage or other issues) or quite commonly by a toasted converter. It happens all the time that a converter has lost close tolerances and squanders a great deal of power potential. Same thing with proper trans pressure - its not that hard to hook up a high pressure guage to check this fundamental of good transmission efficiency, yet is rarely looked at when contemplating lower than expected chassis dyno results.

Thomas

Originally posted by mr 4 speed:
Thats what I say! Just enjoy it and don't pay attention to the numbers,unless they're attached to a timeslip graemlins/thumbsup.gif Exactly. I never considered a dyno. What for? If you're really interested in power readings actual real no BS reading, weigh the boat and keep tabs on your MPH. My AZZDYNO says I'm doing maybe 435 RWHP, and the only way I can even begin to guess is via trap speed and an estimate of weight. But does it really matter? Anyway, thats what the flippin' air cleaner sticker says, 435 HP. Sounds good to me. That sticker don't mean jackshutz when you line them up man. That why I'm being so capricious here. I almost beat a " near 600 hp 509" Camaro. Not bad from a 435hp 427, eh? I was .25 away and even mph'd better than him. 600 HP, yeah right.

Stop obessing in the details and enjoy that ride will ya! Most here don't give a rat's ass about dyno numbers. Have fun. See how it mph's in a 1/4 mile. smile.gif

In your defence, if I had dropped a healthy dime on a motor, I would also probably like or insist on the dyno time. I was toying with having the local bbc guy build me a 750HP 540 street rat ( $6800), and for sure I'd have him run it in on the dyno. More for a 'live fire' excersize before I bolted it between the frame rails than of anything else. ( BTW I'm really glad I decided to stick with my 1/2 price baby rat!).

DRIVE DRIVE DRIVE ON MATT! You don't need no stinkin' dyno sheet. Just be careful some mope with a wimpy lil 435 hp 427 doesnt come along and blow your doors off. A bit embarassing against a high dollar "600 hp 509" I must tell you.

But don't fret. Based on my limited experience, you should be well into the 11's for an ET, and should MPH up near 120. Got me beat on both counts. For now ! ;)

Gene,

Always the positive beat! Whats with you. It must be living in the city of worcester which has this permanaent grey aura of like belgrade, or new haven.
If anything positive has come out of this-- I like the way the car feels. So smooh and responsive-- its unreal. Since you are the solid roller proponent here, I have a 6600rpm rev limiter chip. The usefulness of my engine ends at 6200. I have hit the rev limiter 3 times already by accident, and I have never *ever* done it before with the hydraulic.
Anyway, is 6600 rpm going to kill my motor if I do that too many times. I have a 6200rpm chip, but that is too close because my 6600rpm chip kills the engine at 6500rpm. I Had a 6400rpm chip but I dropped it somewhere into the rug/interior/transmission area of the car and can't getit out without aleast a few hours of work.
Is it worth it for safety to find it and put it in? Or is 6600 (really 6500) just fine for my rat? The builder said the engine would scream to 7500 without even thinking about it, but I still worry. I dump almost all the discretionary income I have into this thing and I take interest free loans from pops for the rest, and I don't want to nuke it for something preventable.
I can't wait to get to LVD! I know I have said it again, but when the following is done I am going to probably drive (not trailer-- I loved the true dual rumble but I can actually tolerate driving the car now and its so smooth its fun!).
1) fix motor mount to clear steering column/header issue.
2) Install torque converter.
3) reinstall old stiffer rear springs and then raise the front with the coil over exactly as much as the rear goes up.
4) inspect braking system and consider a hydroboost if power brakes do not work once I get the "new" converter in.
5) general safety inspection
6) Wheel alignment (when you play with the coil overs you need to realign the wheels, I thought it was bull but I actually went on the highway (lol) with the car and the thing was all over the place.

The goal is to drive to LVD (I dislike NED) as is-- no changes when i get to the track, and get as many runs in as possible to see what I can get out of it. I sort of want to trailer incase something breaks, but I want to cruise too, and unless its gonna cost me $100 in gas then I will proably drive.
The problem is I am graduating from college this may, and preparing for my law school entrance exam, and I need so stop spending so much time on my car that I don't graduate :D . The LSAT I am going to push back to october because if I can't give it 100% its not worth it.

I know I sort of changed this into a bench racingtopic, sorry.

matt

Matt, I'm married to a matrimonial attorney, man you KNOW I have to keep a postiive mental attitude at all times!

If the car is more comfortable to drive, to me that's half the battle. Bet it et'S BETTER TOO. 6600 IS ABSOLUTELY NO PROBLEM WITH A bbc AT ALL. Assuming your vavlesprings are stiffe nough to keep that roller in contact with the cam lobe, adn I'm sure it is.

A good buddy ( the one I jsut about whipped!) has his 509 to near 7 a bit. No problems. Don't fret. Stick the 6600 in there and forget it. I use a 7000. ( used to be a 7400 ).

Originally posted by 427L88:
Stop obessing in the details and enjoy that ride will ya! Most here don't give a rat's ass about dyno numbers. Have fun. See how it mph's in a 1/4 mile. smile.gif

[/QB]I was "anti-chassis-dyno" previously, but I put the chevelle on one two days ago and I learned a lot and picked up considerable power and found a safe nitrous tune on 93 octane fuel - I agree, the numbers don't mean anything, even if they are 4 figures so I won't bother you by posting mine here. ;)

Ryan, again, if I had the time and $$ invested that you do, and was looking for a nitrous tune - to protect my investment - OK. But for a simple old N/A rat ????

I tend to think it's 'insurance' if you will for very high dollar efforts. Teats on a bull hog for something like my $3500 street rat.

Put another way, you're in a different league than me, and most here. graemlins/thumbsup.gif

And even though I'm not a dyno numbers kinda guy, if you want to post 4 digit numbers, I'll be one of the first to say SHAZZAM!

Ryan, don't leave us wondering. Share the dyno numbers. I'm more curious what it made N/A than on the bottle. We wont tell anyone tongue.gif graemlins/beers.gif

SS454, this is a public forum - and we're hijacking this thread! I'll post video in a few days - four figures at the tires, smoking rolling off the tires, on pump gas, through the mufflers with a mild tune.