Black 91 Z28

Hey I went to the dyno Sat and put in 3 runs. Due to a large group/cheap rate thing they were back to back runs with no time for cooling. I was wondering what yall thought about the runs and any friendly criticisms are welcome.

Mods:
Hooker 2055 headers, catco cat, hooker catback, ram/cold air intake, K&N filters.

Thanks!
David

STIFFLER

what did you do to get an extra 20rwhp on your last run?? that crazy.. hahaha but good show... congrats

thats on a 350?

STIFFLER

or is that 249rwhp a screw up or somthing.. if you look on the graph it looks like it peeks at 229 again..?? hmmmm

Black 91 Z28

Yeah I wondered that too. I think it cause some of the torque converters TQ multiplication. I was hoping someone could shead some light on that.

Z28DJP1987

That graph just does not look right compared to the printed numbers, Did you get a print out with just HP & TQ at each 100 RPM's????

ericmac450

Nope man...that's the only printout...(I was there) What are the trends for an L98 on the dyno??? Do number normally drop off that quickly in the upper RPM's????

Haha, one of the Honday guys that was there asked the dyno if black 91 z28's car had the juice...it was funny to see the look on his face when he found out that it didn't.

D Stroy H8

Well... I dont think run003 is accurate at all. With those light mods there is no way in hell you're getting 400 torque to the wheels! So now I'm curious which of the first two runs is the most accurate.

ericmac450

the 400tq is from the converter where the dyno guy punched it...I can't figure out where the hp number on the 3rd run came from though...or why the 2nd run's tq numbers are so much lower...

DannyT

Even though the second one is the lowest peak that looks like the most realistic power figure. There is a noticeable spike at the beginning of the first and third runs which is why the peak numbers are so high. That most likely was from a hard 2-3 shift. Before I even looked at the numbers or graph I estimated 224RWHP so I guess I was pretty close. You may want to take a look and make sure you have good plugs/wires and play with your FP, it looks a little choppy at the top end. Good numbers though.

DAVECS1

iTrader: (2)

Is that the original l98 and are you running an automatic transmission? How many miles are on this car? Those are darn impressive numbers. And yes it is normal for a TPI to drop off like that at high RPM. That the nature of the beast. They make good torque as you can see, but they do not make so much horsepower due to there high RPM performance. You should ask the dyno guy to run the dyno sweep while the car is in third, that way you will not get any shift peaks during the run.

BORLAZ06

hmm...were u running on a mustang dyno. i know those arnt as accurate. dynos can be off as much as 50 hp. i ran my junk at some stang place and i think i got robbed of some hp. great numbers by the way.

Kandied91z

iTrader: (7)

there has to be a flag raised..........

not at you but at whomever did this?

there's no way your car runs 14.7@95 and has 250 horse/400 torque...those mods you have wouldn't make that much of a jump in torque. weird things have happened though i guess.

my car dynoed at 230 horse/310 torque and ran a best of 13.8@104 and that was extreme for a L98 with similar mods as your own.


either the engine for that graph has been altered greatly or someone messed up. 400 torque rear wheel or not is impossible with a stock engine.

pretty insane if it's all true.........meaning you need to learn how to drive at the track then.

Black 91 Z28

D Stroy H8 - Yes I don't think Dyno run 3 is that accurate either. the graph just doesn't match the numbers.

DannyT - Thanks I'll take a look at the FPR though my plugs and wires are new.

DAVECS1 - Yes it's the original L98 and the trans is an Auto. The trans was rebuilt once by the original owner though. I'll ask for a sweep next time, this was my first time at the dyno.

BORLAZ06 - It was dynoed on a Dynojet. A 2003 cobra with exhaust, intake, and blower pully put down 455 HP and 511 TQ if that's any reference.

Kandied91z - The 14.7 was run before I did any of my mods. I did go back to the track afterwards but it was hot, humid, and the track sucked. No one was running right that night. Yeah I know I should be running faster but can't seem to put it down. I imagine the driving part has a lot to do with it. I can't get out of the hole without spinning.

Thanks everyone for the comments. I hope to soon have video of the runs up. Kepp the questions coming. If there are any questions you want to ask so I can prove it's not BS go ahead and ask. I'm not trying to put anything over on anyone.

David

kdrolt

Since the car was tested on a chassis dyno (with inertial rollers), and with an MD8 tranny, then you have to remove the effects of the converter "spike" from the dyno readings. [ Note: anyone that doesn't know what this means, and why, needs to read up on how torque converters work. The spikes are real, and they do provide a boost to the rear wheels, but they are not from the engine -- they are from the converter]. You want to ignore the converter spikes because the aim is to see what the engine is doing.

So based on the dyno tests and ignoring the spikes in the data, the max power would be around 215 rw hp from 3900-4800 rpm, and the max torque would be 325 rw ftlbs at 3000 rpm.

TPI engines typically have very flat peak power curves, so the power seems very reasonable especially for one with very limited mods and measured at the rear wheels. 215 rwhp is roughly 260 at the flywheel, through an MD8 or M30 trans (700R4/4L60, 4L60E). If the engine could breath better, you wouldn't see the power plateau at 3800 rpm; i.e. it would keep climbing. That's exactly why TPI owners mod the runners, or intake, or both.

And 325 rw ftlbs @ 3000 rpm is roughly 360 to 370 fw ftlbs torque assuming linear power loss with engine rpm (i.e., less loss at 3000 rpm than at 5000 rpm) and that's also reasonable for an engine that was rated by the factory at peak fw torque of 330 to 340 ftlbs.

With those items in mind, a 14.7 sec quarter is very reasonble. The torque is very good, but the engine falls off in power at higher rpms because it can't breathe well (which is again, typical, for a mostly-stock TPI engine).

To compare, a 4200+ lb LT1 Bcar with similar engine specs runs 15.0 at 92 mph, so I can easily believe a 3600 lb Fcar should run 14.7 @ 95, or better. HTH

Black 91 Z28

nm

Kandied91z

iTrader: (7)

is that a stock 03' cobra?

those don't have that much power.....about 100 less which would put your car right where it should be.

i'm not saying your lying.....but for the little mods you have that is extreme. i'd love to see you run at a track.

Black 91 Z28

No he had a Intake, Exhaust and Blower pulley.

Kandied91z

iTrader: (7)

so it was basically stock....those three little things won't get you that much of an increase without other advances.

i want to believe you but it's a little hard to swallow. i understand that you saw it first hand and that's fine.

i don't believe it though............i've seen way to many vehicles with all different ranges of upgrades to know what does what and realistic numbers to expect.

if those little things worked that well you would be a rich...so if that's the case i strongly suggest you go into business and play the lotto once for me!

Z28DJP1987

I get the feeling that the day of your Dyno Test and looking at the results the test equipment got out of calibration. This may have happened due the large volume and fast turnover. The numbers do not seem right for your car and also for your ref to the Ford Cobra. Normally, I have a lot of faith in dyno results, but these are suspect. I would get a retest on a normal day with regular test procedure being followed. Just my opinion.

ericmac450

OMG...this board has the same problem that all the others in the world does...no one reads post...

first off...to the guy who thinks the 03 cobra can't put that much down your SADLY mistaken...I've seen 2 here in the city that are putting down those types of numbers...it's not that hard to believe...just because you have not seen it does not mean it can't happen.

To everyone else who say the numbers are BS...yes I do think the third run is high...I don't know where it got the 249hp number...but I can promise you that his car is around a 230-240hp car...and has around 350ft/lbs of tq...why is that so hard for you guys to get?

All day long everyone was right about what they either expected or had already gotten dyno'd at...actually a couple of cars (mine included) were actually a little low.

And about the times at the track...I think it was very possible for him to run a 14.7 and have those types of numbers...he was at stock air pressure in his rear tires (I tried to talk him into lowering it) and he was spinning at least the first 200'. This season were gonna get him lower and we will get some more numbers before any more mods done to shut you haters up...so anyways...I'm calling to all of you people who are calling I think yall all should just :hail: and quit cuz your lightly modded car couldn't do it Have yall ever heard of a factory freak???? Yeah it happens guys.

ericmac450

Ok man...have you ever seen an 03 Cobra??? or messed with FI either supercharger or turbo??? the "pulley" mod he's talking about changes the amount of boost...it's very easy to believe that he could have run those numbers...especially since the exhaust on those cars are VERY restrictive...I think they are dual 2.25" exhaust with a blower??? haha...that's VERY restrictive...

Zenger

that one that had all that tq and hp
the guy who was doing it let the tranny drop into 2nd gear and that was the gears and just the drop of the tranny making all the power

it looks like you made like 230 some rwhp
and 320 rwtq or so ......

DannyT

I wouldn't even call it a factory freak. With those mods he *should* be putting out 225-230RWHP. He also said he ran that 14.7 before the mods.

I agree that most people just looked at the peak numbers and not the dyno itself.

My goes up for that Cobra though. An'03 Cobra does not put anywhere near 455HP and 511 Torque to the crank, much less the wheels. Even if he meant to say blower instead of blower pulley you would need alot more mods than a blower, intake and exhaust to get a 130+HP increase over stock.

ericmac450

Oh well, there is no reason to fight about it...I was there and I saw it all...yall were not...

Zenger

ummm
the 03 cobra with a burned chip, exhaust, blower pulley, cold air intake setup, made almost 500rwhp
and that isn't BS for under 1000 in mods

Muscle Mustangs and Fast Fords
changed the blower to a blowzilla, exhaust and a chip and made over 630Rwhp!!!!!!!
For under 2500 in mods!

Zenger

you do know the 03 cobra is supercharged?
and that adding just a pulley adds like 50 rwhp by itself?
add exhaust and cold air setup and that should put you real close to 500rwhp
I have seen it!

DannyT

LOL, I didn't know it was supercharged. I guess stock is 390HP which is 330RWHP. 455RWHP is about 535 crank HP so I guess a were still talking about a 145HP gain. Either way it's fast.

Kandied91z

iTrader: (7)

you guys also believe that a tpis airfoil adds at least 14 rwhp right.



to Black 91 Z28, i believe what he saw was probably real. i'm not saying the page is made up or he didn't see what he did. however real it was it sounds very unrealistic. the cobra mustang is an impressive machine stock. yes blowers will respond to a good breathing setup like full exhaust, cai, and upgraded pulley. however....getting that much of an increase out of those little things is rather unheard of without alot of money invested elsewhere.

either the dyno is off or whomever did that has alot more money invested than that and it isn't the stock blower. if it is all stock pieces and that is all that was added that car won't last long.

same with the camaro, obviously with those mods it will breath better and get an increase in horsepower.....but, for anyone to believe you will get 100+ torque over stock numbers with those pieces is a bit much and i don't buy it for a second. i've seen what those exact mods do on all different cars as well as my own and if they gave that much of an increase i know i wouldn't have even bothered for an engine rebuild. i mean headers, K&N filters, CAI, and a cat......no way the engine has to have work as well.

look at the jump in torque even............the last two horsepower numbers i agree with. maybe even the 320+ torque, but not 350 and certainly not the 390+ with those little mods.

i wasn't trying to start anything even though it may seem as such. but, i do know firsthand that dynos tend to give relative numbers and aren't always accurate. the most accurate calculator you can have is running at the track. especially mustang dynos they are terrible for accuracy.....but, by all means believe it if you saw it. i wasn't there.

fun Pain

WHAT KIND OF DYNO IS IT,,, every will show different numbers on different car in any given day.... but a dyno is for tuning

Black 91 Z28

Thanks to everyone who replied. I'm not trying to start a fight. I was curious about the numbers as well that's why I posted with a title of "Good numbers??" not "The awesome machine" or anything like that.

I don't belive the 400 rwtq it's just too high and likewise the HP that went with it. I'd love to think that I have that much to the ground but I don't belive it either for the mods that I have. I am trying to figure out what is real and what isn't. Thanks to those who have helped and I hope that you will continue to.

This was my first time at the dyno hence why I was a bit skeptical and hoping the thirdgen members could clarify the results a bit. I hope to get a breakdown of the results per 100 rpms assuming the dyno guy doesn't forget.

I am trying toget a good baseline because I plan to install a cam and put my SLP runners on over spring break. While doing this I also plan to port the heads and intake as well. Then I'd like to try to go back to a dyno and see the change.

As for the Cobra, he may have not been truthful when he was listing he was telling us about his mods. I do know those are the numbers that the dyno said though, be it right or wrong.

Once again thans to everyone.
Other comments and ideas are welcome!

David

Black 91 Z28

It was a Dynojet dyno. Had the drums inground and was hooked up to a PC computer.

DannyT

You're just type of person we were referring about. Can you not see THAT HUGE SPIKE at the beginning of the last dyno run?!
Starting to sound like a broken record.

ericmac450

lol at dannyT...it's like

"read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read, read"

haha, oh well..I guess some people just don't pay attention...their loss. Just because your car didn't do as well with certain mods doesn't mean that another car couldn't...hell were dealing wth 12 year old cars here...David's car is very strong...his motor has very low miles, and is in VERY good tune...are you sure your motor is a strong 5.7??? It could have been ragged out pretty hard man...I'm just saying it could be possible for a certain car to respond to mods differently than anything "you've seen"

if it were two 2002 camaro's I would say the toleranced would be closer and the engines more similar...but over 12 years a lot can happen.

Kandied91z

iTrader: (7)

very true, 12 years of abuse can alter a car greatly.....but no where will you find a 12 year old car with some healthy mileage gain such an extreme amount of power over little mods. maybe if you had read my last post you'd understand that i agree to the most part with the lower numbers and only the higher numbers are reason for question.

some of you really need to get off your horses and quit hiding behind your computers. what makes you think you can talk to people the way you do? i wasn't going analytical on the guy, simply stating that the numbers at the top were rather questional. which is what most of the general public and even himself were referring too. if you want to go indepth with every detail it could be done.......

i can see the lot of you who are so upset have alot of car modding experience so i will gladly backdown. just pointing out the necessities to make the general points.

i have a 03' cobra in my shop with alot more mods then that seeing right around those numbers as well as my own car had the very same mods as Black 91 Z28s (brands were different) and my baselines were no where near that relation. i have delt with numberous amounts of cars throughout my years and have a wealth of knowledge on what works and what doesn't on thirdgens as well as others. i have something i can base my responses off of, what do you?

i have worked with all different ranges of dyno's and know their abilities to be off. while they are nice tunning tools. they have to be setup properly or all is lost. i once had someone run my car on a dyno jet with a 100 horse shot of N20 that only saw a gain of 5 over 5.......does that mean my car wasn't working right? maybe, why did it show almost 80/60 the next run? purely accident i guess.....this stuff happens all the time. i also got my money refunded for those runs.

look at Black 91 Z28s last statement. even he himself doubts the integrity of the 03' owners modifications. while this does nothing to his integrity as he basically made the point from the beginning it says alot to those who are so ready to say that a pulley and a header gives 100 more horses and 150 more torque over the cars baseline.

there is nothing wrong with people asking questions, there's nothing wrong with people insisting they are right even when they are wrong, but there is no need to act like a jerk. i have no problem discussing something but to go so extreme is beyond me.....DannyT, maybe it's time you start buying cds.



Black 91 Z28, i'd say those lower two horsepower numbers are pretty close in relation and anything between 300-315 torque would be a good base line for that as well. still very good numbers and some definately mid-high 13's with some nice driving. if you don't have an afpr regulator you might look into one as well. when you up the pressure and have your pieces ported you'll notice a nice gain with all that air moving.

good luck with it.

DannyT

LOL :lala:

Zeke3Elevn

The HP Boost in the 03' Cobra is very true. It ranges around 450 after you do those mods. A local dealer I know has one and installed a free flowing exaust and swapped in pullys from a lightning and got his HP around 450.

bubbz89

i would say run 1 and 2 are pretty acurrate. you guys get on lucky's dyno?

Black 91 Z28

Hey Yeah we run at Lucky's last weekend. Pretty good turn out overall I just wish more F-bodies could have made it out.

Here is a link to the runs.

http://www.blackws6.com/wtfba/vids/B...1_Z28_Dyno.avi

hope ya have divx

David

Ray87Z

I believe Muscle Mustangs and Fast Fords had a stock 03 Cobra putting down around 360something RWHP stock (390hp appears underrated), and like 380 after monkeying with the air intake silencer. Free mod basically. Several others over on the SVT boards seem to be getting 450ish rwhp after exhaust, intake and pulley mods too...

Kandied91z

iTrader: (7)

some of you need to quit believing all the hype that some of these dyno setups and their numbers put out. in the end it's just a sheet that can be easily duplicated and manipulated to work up a number that is needed. the tolerance and ratings can be easily modified to produce any number wished upon.

run it at the track..........whatever vehicle you have in question. then do the math. until then it's just another number on a sheet of paper. doesn't mean much on the street.

ericmac450

So your saying that a dyno is not an accurate measure of HP?

Yet running on a track is? What happens if you run your car in Denver CO??? You will run like a second or so, slower than if you ran at our track here in Memphis (100 feet above sea level)

So how can that be the end all be all? plus I've been as much as half a second slower in the summer 90+ degrees as compared to 50* weather...

I think a dyno is MUCH more accurate than a time at the track...but using both of those together should be pretty good idea of where your car is at.

-Eric

Black 91 Z28

Face it, every street race, every dyno run, and every dyno run is going to be different. A track has way to many variables, traction, temp, humidity, density, suspension, driver, weight, etc. All these things can change from one run to the next. So a track run is "just another number on a sheet of paper" as well. The most precise way I can think of is an engine dyno on a test stand in a chamber where the air temp, humidity, and densety are controled. I know that more knowledgable people than I dyno on that partucular dyno and I imagine if it spit back bad readings it would quickly develop a bad reputation and no one would go to it.

If the tolerance of the dyno was open to be changed by everyone it would kinda render a dyno usless. Same as changing the numbers on at the track. A dyno is a gauge of the power an engine makes not it's ability to run at the track. Though you can look at the results and know that the 90 hp civic isn't going to go run a 12 and that the 450 hp Cobra isn't going to go run a 16 unless the driver never shifts.

While I'm not a fan of Fords the 2003 Cobra is putting down some impressive numbers even if the hp is off by 50.

David

MelloYello

Sorry, but I agree with Kandied. I think that most would admit that the main purpose of a dyno is to tune a car for optimum power (and perhaps improved driveability). Sure, a nice dyno sheet looks cool and it can impress your friends, but it is certainly not the "end all to be all" in racing (on the street, there are, of course, other factors such as vehicle weight to take into account).

As far as the Denver vs. Memphis scenario goes:
1. Always supply both corrected AND uncorrected times for submissions on this board for better feedback
2. When racing, the other guy is always under the same conditions you are

And finally, I have a friend who runs 12.9@111 in his '90 Civic si and he Dyno'd 245whp (2300lb race weight w/driver) - certainly something you wouldn't expect.

btw...here is the formula to find rwhp:
(mph*0.00426)^3*(race weight w/driver)

DannyT

I agree with Kandied and Mello.
A dyno is a good tuning tool where there are less variables than at a track but the real question is: Are you modding your car for more HP on a dyno or to make it faster on the street/strip?
I agree that they go hand in hand though.
As far as Denver vs Memphis: The air at the track in Denver is the same as the air at the dyno in Denver so both are affected by the elevation in the same way. There is a conversion chart for these things you know.

bubbz89

what kinda deal did you guys get? i am gonna do it, if i ever get my formula running right.

Kandied91z

iTrader: (7)

end all and be all of what exactly?


all i'm saying is you can't believe everything you hear and dyno setups should be used as a tunning tool more than a calculator like so many do.

i know of many shops here in michigan that claim to use their dyno setups as tunning tools and in fact falsify alot of info and parameters to make their "skills" look better.


all i'm saying is look out.....anything is possible, but they have to add up.


bubbz89, what are you talking........price? anywher from 35-80 is the normal range just for three test runs that give info like above. if you want actual tune time it varies and that can be any numberous amount. be careful on what setup you use as well.....some places have been known to do more harm then good.

NOSFEDGTA

Some cars just make more power how hard is that to understand! and yes converters can have a flash effect on torque so to speak. My 88 Trans Am with 178,000 miles on it made 207rwhp and 309 ftlbs The car had a ported plenum, flowmaster muffler, and no airfilter. I put a converter in it and went back to the dyno and it showed 334 lbs. The car with a set of skinnies on the front and bfg dragradials went 13.91 at 98mph with mods listed above.

On a side not my GTA with a 383,super ram, afr heads, 2800 stall, long tubes, and a ford 9in with 3.70s made 497ftlbs and 337 rwph with little tunning on the dyno. It made all the tq by 2750 rpm's and that was running 10.2 on the wideband o2 "can you say rich" I put a 3600 converter in the car and the torque actually seemd to fall off, but the car ran quicker.

Drew

Kandied91z

iTrader: (7)

apparently very hard...............!


your not talking 10-20 grade difference, these people are explaining numbers that just are believable unless some serious work has been done. to each their own i suppose, all though i would be alot happier having a true 250 horse engine that can show tail lights to a supposed 300 horse "dyno" car that in all actuality could be 200 horse.


whatever works for you is great.....there are those who believe and those who want to. just make sure the person working the setup knows what there doing and question everything.

9T1 Z-28

Getting back to the original question/topic....

Those are great numbers for the limited mods you have done to your car! However, I would tend to believe your first pull is more accurate than your last.

I think the dyno numbers are a bit skewed. The first thing that catches my attention is that you made an additioanal 20rwhp on the 3rd run compared to the 1st run. 20rwhp is quite significant.

Just for comparison sake, my 91 Z28 (5.7L TPI) has run a best of 13.8 at 98mph. I dyno'ed 207rwhp and 309rwtq on 2/8/03. The mods I have done to my Z is an SLP cat-back, ThermoMaster chip, filters, air-fiol, and pullies.

I believe my numbers are on the low side due to the fact my car has more than 210,000 miles. I would expect that a fresher engine should be able to make a few more hprsepower than my tired engine.

Black 91 Z28

Thanks for the useful info. If you don't mind me asking how do you launch? What tires do you run. I can't seem to launch without a lot of wheelspin. Any other tips would be useful too.

everyone else is welcome to chime in too.

David