WindyMustang

Finally got some quality shop time today! I updated Indigo with a Steeda CAI, a BBK Throttle Body, and a new 91 Octane tune. Here's some pictures and lessons learned to share with the forum.

Here's how we get started...



I'm using a Steeda CAI, and man is this thing built! The factory cold air box has a duct on the bottom that grabs air from the front of the car - which is pretty cool for a stock setup. Steeda keeps that on their CAI, and ads this velocity stack between the cone filter and the TB.



A few tricks on assembling their CAI...

1. The instructions say to install the cone filter first, then install the brackets to the sheet metal box that seals it up to the hood. You could do it that way, but it's a LOT easier to put the brackets on and THEN install the filter.
2. To get the silicone tubes onto the intake tube and TB, rub a drop of soap on the inside of the tube. This will save you wrestling with it for 30 minutes before your spouse comes out and notices you're working waaaaaay to hard at it.
3. The stock beauty cover on the Performance Package cars crowds the PCV line even in stock trim. With the Steeda installed, it flat out interferes. Fortunately, it's made of foam and easily trimmed.

Now on to the TB...to be honest, I didn't expect much of a difference between the stock TB and the BBK, but I thought it was worth giving it a try. I was pleasantly surprised how well made the BBK TB was...nice smooth machined surfaces and appropriate taper on both the inlet bore and the TB blade. Only one installation note: there's a hard line that runs over the top of the stock TB and has a plastic bracket that sticks into the TB for location. The BBK had a threaded hole in the same place, but the sizes are not close to the same. For now I just tucked the barb into the oversized hole to hold it in place and all seems well.



Finish the install, clean up your work, and you get this tidy looking engine bay...

WindyMustang

Unfortunately the nearest shop with a dyno is 3 hours away. On the brighter side, I bought an iTSX tuner to use with my Samsung Galaxy Tab2 7.0 tablet through AmericanMuscle. Works slick, and with free tunes for life I can install these mods while I'm waiting on my backordered shorty headers.

I tried all 3 variations of 91 octane tunes, and decided I liked the 91R the best. (91S was OK and 91P was kinda funky at part throttle.) But how to measure any improvement? I decided to try a program called PerfExpert from the Google Play store. Very nice little program...if you're comfortable with SI units. (It does display results in English units, but there are a few places where you do need to do a little units conversion.) The support is very good - I had a minor calibration problem and the authors were quick with an answer for me. You'll need information like your car's REAL weight, gear ratios, etc. - and a way to mount your tablet in the car. I used a big suction cup mount I found on Amazon for $20.

PerfExpert does do SAE weather correction with real-time weather downloads based on your location, so what follows are the atmosphere-corrected results (but still ground numbers - not crankshaft).

The on-screen interface is pretty trick - interactive cursors and the like - but for discussion purposes I exported both the baseline and the Round 1 results to a text file, brought them into Excel, corrected them using the SAE factors.



Looking only at peak numbers for a moment, we gained 23 HP and 15 lb-ft of torque at the ground, or 26 HP / 17 lb-ft assuming a 15% loss through my 6-speed manual drivetrain. Not bad!

But the numbers don't really tell the whole story. Take a closer look at the torque values between 2500 and 4000 RPM. That "flat spot" in the base setup was really noticeable to me - and kind of annoying frankly. Now the car just rolls on power smoothly through that section, and it's sooooooo much more rewarding to drive.

At the end of the day, it seems Indigo went from 305 HP / 280 lb-ft TQ to 331 HP / 297 lb-tf TQ, or maybe even a little better.

Can't wait to start on Round 2...

hogasswild

I think you would be pretty close if those were crank numbers. Hate to break it to you, but there's no way with a CAI, TB and tune you're making 331 hp to the wheels. The highest I've seen a 3.7 dyno was 315 and that had intake, headers etc.

Matt's 95 Stang

Like Hog said I dont see you getting up to 331 butttttttt I am sure you got a nice little gain. I would love to see the real dyno numbers. Maybe do a dyno with the new CAI, then one with the new TB and see what the difference is. Either way have fun with the new toys.

Matthew

mariusvt

Maybe I'm crazy, but when I see those numbers, I just assumed the program was estimating/calculating what it would be at the crank. In which case I'd say the numbers while probably not entirely accurate do show you that there were good gains and where about in the band they were.

WindyMustang

No worries on the absolute numbers - heck, I mostly wanted to see if the work made any difference that could be measured by something other than the seat of my pants!

Might make the 6 hr round trip to a dyno sometime when rounds 2 and 3 are done. Didn't seem like it was worth the extra time for these changes.

In hindsight, it might have been cool to get ONLY a tune and see how much that helped by itself. Still, these are pretty easy mods anyone can do with only a little time and investment. They certainly DO make a noticeable difference in how the car drives. Hopefully others will be encouraged to give these a try as well!

WindyMustang

With the help of a couple of good buddies, I installed a new aluminum driveshaft today. Didn't put the virtual dyno on it because I wasn't expecting much of a power difference, but I can say it is noticeable in a couple of ways.

First, a few notes on the install:

• The instructions on the AmericanMuscle.com website are excellent. I have a lift in my garage which made the job that much easier, but it certainly could have been done on jackstands as they describe.
• There is no need to drop the exhaust to do this job. In fact, the exhaust will help you hold the shaft up while you're doing the work, so you are better off leaving it in place.
• Be prepared if your torque wrench doesn't quite fit in the tight space around the axle. If you use an extension to get some more clearance, be sure to increase the torque setting a bit to compensate for the associated loss.

So how does it drive? It drives like...my Mustang. Two things are noticeable right off though:

1. The car seems to wind up and down the tach a bit easier, on either acceleration or braking. This is probably because of the reduced the rotating mass.
2. On a hard "hole shot" launch, the rear axle doesn't tramp as badly. Not 100% sure why..in fact, I kind of expected the reduced mass to make that issue worse, but it went the other way.

As I mentioned in a different thread, this change is mostly about safety and setting up for shorter rear gears at some point moreso than power and such. Still, it's a nice change.

WindyMustang

MPG on some fairly consistent routes is making 25-27 too...and that's with the "R" tune as well. Happy so far!

Hellride

That's a nice review there. Though not always, as long as you use the same tool to measure and traction was the same the final numbers might not be correct BUT the difference in hp may be very close!

On our Cyclone-Performance project car, we'll be running the same setup except for our ported upper and lower intake manifolds. When it's done there should be little to no restrictions to look for in the form of hp left on the table in the intake tract. The only other option would be completely new aftermarket upper and lower intake manifold. https://www.facebook.com/pages/Cyclo...79605112158983

WindyMustang

Great video on your Facebook page Hellride! 4.30 gears and an auto should make for one huckuva run!

I wonder if there's any gain to be had by just coming up with an improved upper manifold? I'm thinking of something like the FAST intake on the GM LS-series engine...something with tuned length runners? On my "dyno" plot you can see the engine getting a bit breathless over 6000 RPM, so somewhere in there is a high CFM restriction...

Are you porting / polishing the heads as well as the manifold?