Well, I've run this Malibu for quite some time now using the track as my science lab so to speak.

I am finally breaking down and doing some long needed data collection. First, I have always wanted an accurate weight/scaling done of the car. It's been weighed twice at the track and showed different results (by some 70 lbs) each time.

Next Thurday I have an appointment at a shop to have the car put on 4 corner scales so I can get an accurate total weight, front to rear weight bias and also corner weights both with me in and out of the car.

After that's done, the car is going to be put on the chassis dyno. I don't ever get enough passes on the track to finely tune the engine, so this session will come in handy and hopefully we will learn what the motor likes and doesn't like. Then I will be able to make adjustments from there at the track for best ET's/MPH.

I told the shop I was willing to spend two hours shop time for tuning which I think should be enough to do some fine tuning/tweaking. Their dyno is a Mustang unit which I understand is on the conservative side?

Anyone care to start making guesses of what the final numbers will be? It won't mean anything really in the end, but hey, what the heck...

I'm most interested in tweaking the tuneup finer than it currently is.

I'm not familiar with the Mustang dyno, I've only dynoed on a couple different Dynojets (248c) . Since you said they're known to be on the conservative side my guess is 450RWHP and 575RWTQ. If your car is like mine you won't be able to get an accurate torque reading because the converter stall speed is so high. If your shop can do aquisition I highly recommend it. A good wide band 02 sensor (heated) can be a helpful tuning aid. Good luck. It's a lot of fun to tune on the dyno smile.gif

If its a Mustang Dyno,,,You're gonna break it Todd,,,Everyone knows a Malibu makes more power than a Mustang graemlins/beers.gif

I'll take a shot at it,....how much does the car weigh with you in it?
On another note, how far are you from 75/80 dragstrip. I may be down there soon.

Jim

Originally posted by Epistuff:
I'll take a shot at it,....how much does the car weigh with you in it?
On another note, how far are you from 75/80 dragstrip. I may be down there soon.

Jim The car is approx 3500-3600 with me on board.

I'm just 40 minutes from 75/80 Jim...closest track to me. When you gonna be down this way?

Todd,

I'm going to guess 423 RWHP @6500 RPM

OK, I say 549 RWHP. That's my story and I'm sticking to it.
75/80......If we go, it will be Sunday. Going with my friend that runs the AMX. Working on his car today. If it is ready, we'll go there, if not, maybe some test/tune at the local strip up here. If we go local, I will take the Chevelle and make a few passes with it also.

I've followed the weather reports and it looks like two solid days of rain on Wednesday and Thurdsay. The decision was made to reschedule the dyno/weight time for next week somtime.

I just didn't like the idea of trying to dyno or tune a car in 100% humidity, so we'll put this off another week to where the air conditions will hopefully reflect the past few track outings and give a more realistic outcome.

OK fellas, you've got an extra week, so throw out some more guesses.

Jim...kinda feeling quite overconfident aren'tcha with that guess? lol.

Originally posted by 10secBu:

Jim...kinda feeling quite overconfident aren'tcha with that guess? lol. I used an average of 10.7 @ 124 and put that into one of those dopey HP calculators. That's my story and I am still sticking to it.

tongue.gif :D

I've heard conflicting reports Jim, but one engine builder had pretty good proff that those calculators & slide ruled provided flywheel HP, not RWHP.

The actual chassis dyno runs would enable me to be able to tell if he was right or not.

I have a hard time believing this lil 414 makes over 600hp at the flywheel, much less over 500 at the wheels...but I wouldn't mind being wrong this one time ;) .

My own guess is between 425-450 at the rear wheels.

My guess is 487 RWHP.....

448 RWHP on a Mustang.

If they don't have a WBO2 I wouldn't bother. The best thing is to have an O2 bung welded in before hand to get the best readings rather than stuffing it in the exhaust.

I've always had to retune a little at the track after making best power on the chassis dyno. But you can see what helps and hurts on the chassis dyno. I'd guess your car is very closely tuned by your track performance.

really dont keep up with the B/B stuff but i,ll take a stab at it. 472 RWHP.

I won't make any guesses, but I will tell you about my experience with a chassis dyno. A company brought a portable Dynojet to my local track a couple of years ago. They charged $70 for 3 pulls. My car at the time was a 69 Camaro. It had a 360" SBC and a TH350 with approx. 4000 stall. The car ran a best of 11.40/116.9 @ 3260 lbs. It made 323.6 hp @ 6000 and 416.3 lbs/ft @ 3100. I know the stall speed screwed the test results up because torque ang horsepower crossed at 4100 NOT 5250 as they should. The guys with dyno couldn't explain it. All they could say was it's right,it makes what it says. They did say that the tires could affect the output. Something about the tires absorbing the power instead of spinning the rollers. They told me to run my slicks at race pressure, but I think that was the wrong move. I guess what I'm trying to say is use a company that is very experienced. Not everyone with a chassis dyno is knowledgeable.

Im gonna go with 437 whp @ 6400 rpm smile.gif

Man, I just can't catch a break here. I'm trying to follow the weather a little bit for scheduling the dyno/weigh session next week. I need to give the shop a couple days notice to get on their schedule. I'm in a catch 22 scenerio as the weather reports are showing rain at least 3 days next week with a possible one dry day in between. At this point, the forcast is to far away to be accurate as that one possible dry day could swing forward or back in the week. I'm available to go to their shop either Tuesday or Wednesday, but don't know which day is safe to schedule the work :mad: .

Man, this sucks with all this rain coming through. If I didn't want to try and have this stuff done, it would be clear and sunny till December graemlins/angry.gif .

So I get to blame you for all this rain.... tongue.gif

I'm going to guess 437 hp and 446 tq

I finally got another appointment for the dyno/scale work. It's tomorrow at 8:00 am.

As long as things go as planned, I should be able to post results sometime in the afternoon.

Ok, finally home from a long day at the shop.

First thing, the car weight.

With no driver, the weight was 3332 lbs with 55.6% of the weight on the nose. That's 1852 lbs on the front, 1481 lbs on the rear.

With driver, the weight was 3532 lbs with 55.3% of the weight on the nose. That's 1953 lbs on the front and 1580 lbs on the rear.

Man, those digital scales are handly...have the individual corner weights recorded as well.

Now, the Dyno results. I lost count, but I'm certain we made at least 12 pulls, maybe as many as 16. The car went on the rollers at 8:30 and came off at 2:30 pm.

As a note, this dyno is a Mustang unit that I believe is an eddy current model. He inputed data for the specific vehicle weight and body style and the dyno simulates wind resistance, etc...inertial mode or something.

Anyway, the first pull off the trailer was 396 hp @ 6700 rpm and 347 ft/lbs @ 5700/5800 rpm.

A second pull was made with no changes to verify the first and it was nearly dead on...397 hp @ 6700 rpm and 344 ft/lbs @ 5800 rpm.

Over the next couple hours, we tested many things including jetting, timing, a HVH tapered 1" carb spacer (in place of the current 1" open) and also a Holley 1000HP annular carb (in place of the current old Carb Shop 850)...also tested a different type & heat range spark plug.

In the end, the final jetting turned out to be my baseline jetting...for best power. Also, I had 38 degrees timing and we found the car seemed to like 36 degrees a tad more.

The plugs gave no difference and the carb spacer made less power. This surprised Charlie (tuner) as he claimed most the cars he tests respond favorably to that spacer. The HP carb also made less power (in all fairness though, box stock, no jet changes were made) which was a surprise as well...good for me as that saves me from considering replacing my current parts.

What we did find on the dyno was the carb didn't get full throttle...the linkage was binding up on the return spring kit and the cable attachment. Some quick mods resolved that and the dyno numbers jumped easily by 15 hp.

The best numbers on the sheets I had printed (only printed a couple, not all) was 418 hp @ 6750 rpm and 359 ft/lbs @ 6000 rpm.

I saw some numbers as high as 424-428 hp, but they were more peaky numbers...which were eliminated by smoothing the output data.

I'm pretty satisfied with the testing. We verified my jetting was pretty much dialed in and the timing was darn close...could use less timing on good air days and 38 degrees in hot muggy days. We also learned of the throttle linkage issue which is now resolved and picked up easy power in the process.

The air in the morning runs was at 450' corrected altitide and the air towards the end of the day was over 800' corrected altitude...so we picked up more power than the numbers really show.

This shop owner runs a NMCA Hot Street Mustang as well as two NMCA Pro Nostalgia cars...FE Ford powered...with all the cars running in the high 8's, low 9's N/A. He has a great deal of experience tuning N/A cars. He also has their race engines dynoed before installation in the car. It's there experience that the engine dyno (Kuntz & Co) vs their Mustang Dyno in inertia mode reveals about 30% difference or loss through the drivetrain. It was his opinion that this lil 414 was making somewhere between 600-625 hp at the flywheel...based upon his data he's collected...and he's quite conservative and doesn't shoot for high peak numbers for awe factor. He tries to tune for real world conditions and power.

Lastly, converter flash was verified on the dyno and shown to be 5500-5600 rpm.

Man, the lil rat is just pooped out tonight and is deserving of a long winters rest and cleanup. My ongoing oil leak showed it's ugly head with some oil squirting on the headers and making for some nasty smoke screens upon shutdown...that's a winter project to locate.

Man, the Dyno is quite intimidating to myself...your pushing a car really hard on there time after time...and does the car jump up when you slam the throttle...kinda cool, yet not something I want to put the car through for a while....I did all the driving and 80% of the mechanical work with Charlie as the "Crew Chief" making the tuning calls.

Sounds like you had a very busy day.....I would have guessed a little more at the wheels....But who cares.....with it running 10.60's :D :D

Congrats on a good day......

Todd,

I have to admit I'm surprised that the numbers aren't higher. Looking at your signature it seems you lost 2 MPH in street tune. Was this difference in weather between the two runs, or was it a result of the full exhaust and other "street" mods that were made? I think that 418RWHP is getting into the ball park, and as I stated all along I think the high stall converter really reeks havok on the numbers. My car made 20RWHP more with the old hydraulic cam/4 speed than in the current configuration. However we both now that the car is making tons more power now than with the old setup. Were you testing with street tires? I'm curious, because one other factor that different between my two abovre mentioned dyno sessions is that with the stick I was running BFG DR's and with the auto I was running slicks. Not sure if that makes a difference or not. Clearly your combo makes a ton of power as evidenced by the ET's you've posted in race and in street trim. I'm not sure that Mustang dyno did you justice. However in the end, the only important numbers are displayed overhead at 1,320'. graemlins/thumbsup.gif

Thanks Scott, long day indeed.

Ken,

The bests from this year and last year were at two different tracks. The street trim runs were at a track that is typically a tenth & 1 or 2 mph slower than the quicker track (75/80 vs Cecil). I'm certain that the car would easily go mid/low 10.70's at Cecil in similar air...just missed my chance to run at Cecil or MIR...gonna wait till spring now. The throttle deal "should" help on track as well ;) .

Yes, all runs made on the drag radials with 18 lbs of air just like at the track.

BTW, just checked...the weight listed is a little light as I just checked and my cell has only about 1/4 tank left (12 gallon cell). I always run at the track with the cell full for ballast...so were likely about 8 or so gallons of fuel weight light with those scale weights.

What's a gallon of fuel weigh? 7 or 8 lbs?

We did the dyno runs first, then the scaling...should have ran out and topped the cell off before weighing...as that changes the front to rear percentage as well.

I think I forgot to mention that all pulls were made with the full street exhaust in place including the full tail pipes graemlins/thumbsup.gif .

For what ever reason, the car backfired through the exhaust upon deceleration of the pull...about 4 pops each time and the dyno operator told me there were 12-18" long flames shooting out the tail pipes :eek: .

Definately need to get this oil leak issue resolved...gonna have to pull the engine this winter to be able to pin-point the source.

Hey Todd sorry I have nothing to add I just wanted to say I saw you at the Westminster car show at Cranberry mall. I didn't see you but I saw your Malibu, just wanted to say hey. graemlins/waving.gif

Brandon

Hey Brandon,

I thought I saw a Chevelle that looked like yours...must have been Eh?

I think we were all too busy trying to keep warm...dang that was cold. lol.

Todd,

It looks like you got some good information out of your trip to the dyno. From your car weight and ET's that is about what I would expect on the dyno numbers. At least from my experience dynoing cars with a bit of gear, high(ish) stall, and some decent gearing. You could probably expect a little more on a Dynojet(10-20 RWHP). For reference my car put down 389 RWHP (Dynojet), is 3600 lbs, and ran equivalent to 11.30's in it's final form before pulling the plug.

BTW - gasoline weighs in at around 6 lbs/gallon. The exact number will vary depending on who supplies it as the specific gravities/weights vary with producer. So figure about another 50 lbs. of raceweight.