[harry k]

Since the other thread got shut down
.
now we can start talking about actuall "Controlled enviroment testing" vs track testing that i am willing to share my hard earnd experience as some would like to hear!!!!

i have the 74 trans am with 400-461 combo
specs
461 CI 800cfm SD 273 Cliff R carb, Edelbrock RPM int.,WCCH 315cfm E heads 10.4 comp, SD" old faithfull" Comp HR cam Crower 1.6 full rollers, Tribal tube Try-Y headers Ram Air Resto exhuast, Pro Built 700R4 ,Conti 10" 2700 stall,3.73 ratio

the car here in our Cali tracks runs 11.70ees @ 116.8 117 mph weighing 3550lbs
(this same combo i see in some signatures at 120 mph ,makes me wonder if the California ozone layer air has horsepower killer in it)

anyways here is what i did, when the latest talk in here about adding HIPPO solid rollers on the Hyd roller cam was the ticket
went and ordered the Crower HIPPOS from ACE PPR
installed them, set them cold lash .006 in no time ,fire it and hit my Dynojet chassis Dyno

here is the graph
blue line pull @ 5900 see cursor power falling to352 rwhp with hyd roller lifters
green line pull @5900 see cursor power staying @382 rwhp with crower HIPPO solid roller lifters
thats 30 RWHP staying flat at same rpm


so what do you think this should translate at the same track huh?
here is the slip car number #556 same combo with hyd roller

here is after solid roller HIPPO lifters installed with 30 more flat power at 5900 rpms
car#7794 my NHRA comp lic number


so what do we have to say now about racing cars at the track and we dont race dyno's as some say !

where is that mile per hour gain for that 30 more rwhp measured on the "controlled enviroment dyno" and not at the track ?

[grandville455]

Interesting! Guess first question is the weather on each run? Shift points the same?

[mchell]

Your 60'........you were .043 faster on your first slip.....that's a lot of et you left on the table because of the slower 60.......get the 60 at the same as the first one , then you can compare...even that's a maybe as weather conditions will also play a huge part......ain't easy comparing changes........LOTS of variables to consider

[nachomax]

Did you switch back to the hydraulic rollers, because it shows that those solid rollers are no good...

[LiL Jack]

That 60' is really bad for that mph, did the car spin?

[Rocky Rotella]

Did you notice any difference in the idle quality and/or low-speed manners when moving to the solid rollers?

[Half-Inch Stud]

Someone school me on the HIPPO lifters: what do they do differently form standard HYD lifters, and how do they do it?

[mysticmissle]

Hippos are solid rollers

[Ron H]

High pressure pin oiling on a solid roller lifter.

Made more torque, spun the tires, need to tune to the lifters more.

Solid roller cam with them lifters would help it!!

[Cliff R]

Harry, if we can keep this thread civil, there are some things to learn here.

Just because I mentioned in the "other thread" that we don't race dyno's, it doesn't mean we don't use them, or can learn from them. With few exceptions, all the engines we build here are dyno tested.

Testing at the track is a far more "dynamic" environment, with considerably more variables than your "controlled" dyno set-up.

Anyhow, couple of things to mention here about your testing.

The car being used to do the testing must be able to run the numbers. It MUST be deadly consistent run to run, especially on the starting line, as deviations in 60' times throw the results off considerably.

It took me years before I got my car running well enough to test parts at the track. To show how well it runs here are the last two timeslips from my test and tune session last summer, right before heading to Norwalk for the Tri Power Nat's:


R/T: .505 .514
60': 1.6230 1.6289
ET: 7.3169 7.3188
MPH: 94.35 94.36


Those runs were made 23 minutes apart, and the last two of 6 runs we made that day. To get timeslips this close, we do EVERYTHING exactly the same run to run. Same burnout technique, stage position/rpm, shift points, etc. I even heat soak the engine before any runs are made, and after cooling it between rounds make sure it is EXACTLY at 180 degrees when I start my burnout.

I would also mention here, that my car NEVER varies much in 60' times run to run, or even very much from outing to outing. Even running in pretty good air to the worst weather you'd want to race in, I don't see the car slowing down all that much in 60', and it runs deadly consistent all day long either way.

Anyhow, I'm assuming here that you ran in pretty similiar conditions to record the two track runs mentioned in the original thread. Similiar temperature, humidity, wind speed/direction, etc. With this in mind, the 60' times should be close to the same, which they are not.

Also, by looking at your dyno graphs, the engine also appears to make very similiar power through most of the loaded rpm range, falling off quickly up near peak HP. Keep this in mind as you read on.

With my own car, I stage at 1000-1100rpm's, and my converter flashes to 3500rpm's. If testing parts I shift at 5500rpm's for most runs. Here's the neat part. I can shift at 5000rpms, 5500rpm's, or even 5800rpm's and the ET will only vary a few hundreths of a second. Why? Because my car leaves hard and consistent, and the engine has a very broad/flat torque curve. For the entire run, it's only spending a few hundreths of a second up near the shift point right to start with. So the additonal power the engine makes in the higher rpms, doesn't get applied as directly as one would think to the track during a run.

In other words, my car leaves hard, as does the one in question here, it pulls up through the rpm range, and when a shift is made it's still pulling just as hard in the next gear do to the excellent torque production the engine has betweem the launch rpm and shift rpm point.

This is why the measured power difference the dyno showed us is available, isn't have a dramatic effect on ET or MPH. It is still having some effect, but from the information provided, it's difficult for someone reading this to know all the other things going on that could have slowed the car down on that second outing compared to the first one.....Cliff

[johnta1]

That's one reason why you need the weather data, otherwise it's a crap shoot on what the differences are.

Also, this is on a chassis dyno, right?
What were the weather data for those runs?

Also what were the shift points on the runs?
You should have shifted about 500 RPM higher on the later runs.
(to get in the power band according to the dyno #'s)

The power may be out of the torque converter stall range, also.

[Half-Inch Stud]

Okay, so the classic Solid for HYD Lifter difference is evident on tat DYNO, at high RPM.

Seems the RWHP plots show a diff, & I expected RWHP to read higher for an 11.7 116MPH car, so could the DYNO differences be from strap-down quality?

[harry k]

sure Cliff i am with you civil & all that

Ok i go on quoting each reply to answer 1 by 1 for the new guys joining this thread not knowing where we got shut down

or i can say this to start with

my whole point of bringing this thread up (which it takes me long time to upload images & sift thru notes, write all this up) is : after years of reading your replys regarding testing ,you make the beginer level forum readers, the track is the only way to confirm the cars performance ....

as i stated in the other thread when the changes are so small, as i called it "spliting hair" you were not paying attention to those lines

here in this matter +30 rwhp on the Dyno, i am not talking about et ,never mind the et
where is the gain in miles per hour for the top end ?????

see what i mean , i am trying to prove to you that track is not "controlled enviroment"
so you see the whole point when all are stating there are many variables to count for,
when you are stating the Tomahawk & Holley did not perform as your good as your modified Q-jet intake & carb !!!! aparentley all the variable results were favourably to you.

[badls1]

Well you are almost tracing your old horsepower numbers except up top. Did the torque numbers increased down low?

Needs more converter/gears perhaps to help the engine rev quicker. What rpms are you passing trap speeds at?

[harry k]

Originally Posted by grandville455

Interesting! Guess first question is the weather on each run? Shift points the same?

the weathers were in november & december
at this track Famoso auto club raceway is good time of year where there is not much difference(pvt test & tune run as many you want)
5800rpm shifts

Originally Posted by mchell

Your 60'........you were .043 faster on your first slip.....that's a lot of et you left on the table because of the slower 60.......get the 60 at the same as the first one , then you can compare...even that's a maybe as weather conditions will also play a huge part......ain't easy comparing changes........LOTS of variables to consider

exactly .... the car started making more power everywhere
lots of variables ...thank you
this is my point above to Cliff ....non of this on Chassis Dyno in order to make claims where Tomahawk &Tom V's Holley performed poorer !!!

Originally Posted by nachomax

Did you switch back to the hydraulic rollers, because it shows that those solid rollers are no good...

WHO SAYS THEY ARE NOT GOOD ???

Originally Posted by LiL Jack

That 60' is really bad for that mph, did the car spin?

no Jack it did not spin , the car has pro touring type front coil springs 650lbs, it et's on weak side ..

Originally Posted by Rocky Rotella

Did you notice any difference in the idle quality and/or low-speed manners when moving to the solid rollers?

Rocky love those solid lifter conversion helped everywhere,yes smoother idle as hyd roller lifters & not noisey at all ....


=johnta1;4535899]That's one reason why you need the weather data, otherwise it's a crap shoot on what the differences are.
as i said above about this time of the year this car runs within its times & if we spliting hair yes u need weather station


Also, this is on a chassis dyno, right? yeson Dynojet 248X dyno
What were the weather data for those runs?John please take a look at the graphs top right corner where it states CF correction factor :uncorrected
i always do my tests back to back uncorrected in order to be most actuall test results ,so it would be apples to apples comparison

Also what were the shift points on the runs?5800
You should have shifted about 500 RPM higher on the later runs.yes if i am seeking better et
(to get in the power band according to the dyno #'s)

The power may be out of the torque converter stall range, also.
the converter is on the money ...just ask Cliff about Conti tq's

[/quote]





http://www.hkmotorsportsdynoshop.com/

[LiL Jack]

Nice ride! I always thought those valve covers were sharp looking!

[harry k]

Originally Posted by Half-Inch Stud

I expected RWHP to read higher for an 11.7 116MPH car,

Mark
here is what i got next to my monitor in my shop that i share it on daily basis

[Ron]

Holy krap Harry.....you have grey hair now. LOL!!!!

Something is wrong with the 60 foot time. In my blue GTO I would have a 60 of 1.70 and run 12.10's at 114 MPH at LACR. I'm sure you are making more HP than my blue car.

Well maybe not as the car with me in it weighed over 4,000 pounds.

[BruceWilkie]

The way I see it... if it mph's the dyno numbers and only et is off its likely track conditions or something other than engine tune/weather. If mph is down as well as et then the plus side is you know there is more in the combo. Just more areas to consider and refine if need be.

[Cliff R]

"so you see the whole point when all are stating there are many variables to count for,
when you are stating the Tomahawk & Holley did not perform as your good as your modified Q-jet intake & carb !!!! aparentley all the variable results were favourably to you."

Harry, read these two timeslips again.


R/T: .505 .514
60': 1.6230 1.6289
ET: 7.3169 7.3188
MPH: 94.35 94.36


My car runs the numbers IF it hooks on the starting line, which it did for all the runs we logged that day. If we change nothing, and the runs are made in the same weather/wind, etc, they will be near mirror images of each other. Sorry if that's not good enough for some readers, but it's the best that we can do with this type of testing.

We dialed in everything BEFORE bolting on the Tomahawk intake.

The first runs without a spacer were slower everywhere, 60', ET and MPH. (Same as every other single plane intake I've ever tested to date). I would add here that we see the SAME thing on the dyno, some loss of low rpm power, and a significant shift in power to the upper rpm's. This is going to hurt 60' times with the relatively "low" stall speeds that we use, no way around it.

We added a 1" spacer and it still ran .09 seconds slower in 60', but hard enough on the run to be 2 MPH faster on top end and almost as quick in ET. This is EXACTLY what we expected, as the dyno testing we did with that intake showed that it really likes a nicely blended 1" spacer for best results.

This happens for several reasons.

Those intakes respond well well to the added plenum volume provided by a spacer.

Moving the carb up gives the incoming air a better shot at the tall/narrow runners.

Moving the carb up out of the plenum reduces turbulence and/or disruption of airflow caused by the throttle plates sticking pretty far down into the plenum area.

One last note. There are always "variables" with anything this "dynamic", even engine and chassis dyno's. The "controlled" environment doesn't fully reflect to us how the vehicle will use the engine power at the track.

There is also something else to consider, that could be a factor in the testing reflected in this thread. On the chassis dyno the fuel delivery system may have been adequate for the power level. On a hard run, it may not be keeping the carb full. I fought that deal with my own car, and when I finally got everything up to par, I was rewarded with greatly improved ET with more MPH, responded better to tuning, etc.....Cliff