Modified 1980 Dyno Run with Graph

[joelittel]

I am in the process of tuning my car and took it to a dyno in hopes to "do it the right way." The dyno guy kind of laughed when I pulled in because the FIAT was almost too small to safely fit on his dyno lift.

The car is a 1980 with the following modifications:
Vick's Programmable Fuel Injection
Autoricambi High Performance 2L head
Allison's 285v cams (regrinds not billet)
Adjustable Cam Pulleys (full lift set at 109 degrees for both)
Domed Pistons (9.8 Compression Ratio)
Aluminum Pulleys (Crank and Water Pump)
Lightened Flywheel (I didn't weigh it before install, came from Miller's Mule)
Crank Scraper
Allison's Header & Full Exhaust System (no cat)
Vick's Texas Head Aluminum Radiator
Allison's Autocross Clutch
Multi Layered Steel Cylinder Head Gasket

There may be other modifications that I'm overlooking but those are probably most of them

[joelittel]

There is so much to learn when tuning a car that I feel a bit overwhelmed. However, I am happy that I came in approximately 21 hp, and 16 lb-ft over stock, (not bad for an engine I built in my dining room).

The Vick's system came with a tune installed but my car has been so heavily modified that it required additional modifications via Tuner Studio. The guys at Vick's were extremely helpful in getting the car up and running smoothly after I installed their system.

[klweimer]

That's cool. What did it cost to run your car on the dyno? How many runs did you make? Tweaking between runs? Any pictures? I've thought about doing this as well.
Kirk

[joelittel]

It was $125 per hour, and I went with a two hour block.

We made 9 pulls and tweaked in between each. The guy with me was kind enough to teach me a bit as we went.

Unfortunately no pictures, which I really regret now. I was in the car up on the dyno, about 6 feet off the ground, so once we were in it really felt best to stay put.

I'll go again and when I do I'll take pictures.

[So Cal Mark]

I would expect to see a flatter torque curve and a higher peak hp. Does the programmable FI also control timing? I'm curious what your timing curve is

[joelittel]

The programmable FI does control timing.

I wasn't offered a timing curve at the shop either. Would a timing table show you anything?

[So Cal Mark]

I'm must a bit surprised that the torque curve isn't flatter. We've built many engines with similar specs to yours and I expected a more peak power and a torque curve that rises quicker and stays flatter

[joelittel]

Maybe I've got my cams setup incorrectly. If full lift was happening at the wrong time I'd be reducing my compression ratio and suffering from a loss of available power.

It does drive/feel better than ever though.

Also keep in mind that I tuned this setup based on what I've learned from forums. There's an excellent chance that I've left so torque and horsepower on the table. Vick's helped me get it rolling but after that point it was all me, trial and error, post-read-tweak-repeat.

The good news is that this means it's not done yet!

[So Cal Mark]

it would be helpful to see your ignition timing curve

[nelsonj]

I'm (morbidly) curious - how much do ya think you spent on all the custom parts? (It's sounds like you did all the labor yourself).

[joelittel]

I have all the receipts but am not quite ready to add them up... fearful of the sum I guess.

Some things I was able to get second hand, and some where just less expensive a few years ago when I started buying parts... but I know I've spent more in modifications than I did on the purchase of the car.

If I'm ever brave enough to add it all up I'll post that number here, but tonight I don't want to know.

[joelittel]

Started over.

I've loaded the original tune and have been letting Tuner Studio auto tune the VE table. Once Tuner Studio stops altering cells I'll take the car to the dyno and post another graph.

[baltobernie]

My engine is pretty similar to yours, but with a single carburetor, OE exhaust manifold and homemade exhaust. I agree with Mark; you've got some more ponies in the corral.

[joelittel]

My second dyno run was entirely different than the first... night and day different. The results will probably be difficult to compare without experiencing them first hand while in my car, but trust me I've been smiling all day long.

The firsts graph was created on a Dynojet which only allowed us to tune the WOT, from what I understood at the time. Maybe that's not entirely the case but that's what we did.

Today I was on a steady state Mustang Dyno. Way more fun, but commonly referred to as the "Heartbreak Dyno." It takes more information into account and as a result is supposed to be more accurate. When I saw my numbers I was... heartbroken... but only until I drove the car home.

I'll post the graph and photos shortly, but first some background info.

With the Dynojet we simply strapped the car down and started tuning based on what the graph said. We adjusted the VE table based to what the dyno tech saw in the graph and then made another run.

As you read previously I was impressed with the car and generally considered it an improvement over stock. I was actually very pleased to be honest, simply because it really was better than it began.

The Mustang was a much more involved process. The software required the weight of the car, plus me in it, as well as a value that represented the aerodynamics (DynoSource had this info, I did not) before we could start. The Mustang also controlled the load put on the engine, whereas the Dynojet was simply a heavy drum rolling under my tires. On the Mustang we were able to dial into each cell in the rpm range of my table (12x12) while I worked the cells from low kpa to high. For example, while the Mustang held my car at 3000 rpm I was able to adjust cells from 30 - 100 kpa etc. etc. It's hard to comprehend until you've seen it or done it but the Mustang really does keep the car at a predetermined rpm while you load it up. Very cool.

At the time it didn't feel like we were making any progress at all. The car bounced a bit on the rollers and the only reference I had in terms of performance increases or decreases were the hp and torque numbers reading out on a small screen near my car... and again, they weren't all that impressive. I kept wondering when the magic was going to kick in. When was I going to see that big jump in hp or ft-lbs???

The first run produced 71 hp and 97 torque. Effing heartbreaking to say the least. The dyno tech immediately noticed my disappointment and told me to forget about the numbers. He literally said, "Forget that $#!t." He says that everyone is chasing a number but promised that my drive home would feel like an entirely different car... and he was right, it did.

One thing of note was that I still have the same dip in the torque curve as before. Relatively same shaped graph, just lower numbers. This was explained to me as a common issue with Dynojet products. I was told they routinely show values up to 12% higher than the Mustang but that the Mustang is a more accurate measure of what your actually putting out. It calculates wind drag at speed and horsepower loss as a result, etc etc.

The dyno tech said that the dip in my torque curve was most likely caused by me when setting up my adjustable cams. He explained how he'd go about smoothing it out (advancing and retarding the cams and spark tables etc etc) but we didn't have time to dig into that today. He was confident that he could get it to put out that low end torque every street car owner is looking for, but we had a small block of time to work with today.

We made lots of pulls, setting the testing window for specific rpm ranges each time and running tests until I got the best results I could. Then we'd move up to the next rpm range and start the process over. We made minimal changes each time, checked the graphs/data and adjusted based on the findings.

I rented the Mustang for two hours so I didn't have a lot of time to really dial it in, cams, AFR and Spark tables... but Holy New Car Batman! I'll be going back as soon as I can to finish the job. The transformation between before and after is hard to describe without experiencing it first hand. If you live close enough to stop by, please do because a witness to these results would go a long way.

Previously I was at "101" hp @ 4750 rpms. According to the Mustang I am now at "94" hp @ approximately 4750 rpms.
Dynojet max torque of 116 ft-lbs @ approx. 4350 rpms, and the Mustang 108 ft-lbs @ 4302 rpms. All tuning, on both the Dynojet and Mustang was done in 4th gear.

The difference is night and day between the two tunes. I know the Mustang shows lower numbers and at first glance the second tune appears to be the lesser of the two, but that is simply not the case at all.

My car has never been this much fun to drive. I've always been able to spin the tires and slide turns like a hooligan, but today I was doing it in 2nd and 3rd gear. Never before has 5th gear been fun, but on my drive home today it was amazing. At 85-90 mph I was still pulling away from traffic and only getting close to 5k in the rpms, and it was still pulling strong. While on the hwy I never had my foot all the way to the floor and I didn't exceeded 5k, so I assume it has more to give.

I plan to put the car on the Mustang again in a couple weeks and really dig into this tuning business.

All I can say is, Night & Day difference and I'll be hiding the keys as a result.

I'll post pictures and the new graph soon.

When I'm done tuning I'll go back to the Dynojet and post another graph so that it truly is apples to apples.

[nelsonj]

Always good to hear success stories! Congratulations. And I agree, it's not about numbers but how the car performs/gels with the setup it has.

I'm still curious about the $$$ in the engine, and how much 2 hours of dyno time costs.