Baseline Performance

[Bulls99Sub]

Greetings all,

I have a 99 Suburban that I am about to start modifying. I have several items on hand and will be purchasing a few more in the coming months. Mods will be applied as follows:
- SSDiesel 4 inch exhaust with 5 inch tip
- Air Filter
- SSDiesel air intake system
- Kennedy computer -- May purchase
- FSD Cooler
- Kennedy intercooler -- possibly June

In order to track the contribution of these modifications, I will be using my G-Tech Pro meter to determine the contribution of each modification. Baseline - completely stock - runs were completed yesterday. First, some info on the vehicle: bone stock 99 K2500 Suburban, LS pkg, 3.73 limited slip rear, 107,000 miles, excellent mechanical condition, stock 245/75R16 tires, 3/8 tank of fuel. I bought the truck used, but I believe that it has all the original fuel system. Test conditions: very nice Maryland Spring day, 70 degrees, <5mph winds, average humidity, straight, nearly flat stretch of road. Baseline - stock - results of three runs in each direction averaged:
0-60 11.4 sec
1/4 mile 18.1 sec at 77 mph
Runs and speeds were very consistent, most varied by less than 0.05 sec and 0.5 mph.

Exhaust and air filter systems go on this weekend, hopefully. I hope to have the next two sets of runs by Monday. I will try to duplicate all test conditions as closely as possible for consistency. I know that this is not as accurate as a dyno or dragstrip, but the G-Tech Pro meters were picked by Car and Driver as one of their favorites. G-Tech also provides HP and torque curves, but I so not plan to post them to avoid controversy.

Thanks, Bull

[Turbo Al]

Excellent idea Bull,
I set my baseline on the track and the dyno and it really is a hassle unless you actually own a track or dyno :rolleyes:
Good luck with the installs.
Al

[AndyL]

0 to 60 in 11.4 seconds on a stock 6.5? That doesn't sound correct.

I have timed only by stopwatch with my below configuration and get a best of about 11 seconds.

Anyone else?

[Billman]

C'mon Bull, post some numbers. A little controversy is a good thing.

Calling you a liar or disagreeing with your numbers gives some of us(myself included) something to do.

I see Andy has already started.


It's all in good fun...

[Jim P]

My truck will run 0-60 in about 11 seconds but I have trouble keeping the tires from burning off for about the first 100 feet. I also have a 5 speed and was a little late on a couple shifts. I always wanted to try it in 4 wheel drive to keep it from spinning. I believe I could get it down to around 10 seconds but mine is far from stock.

[moondoggie]

Good Day!

I hate to ruin the fun of tearing apart his numbers, but even if they aren't accurate & traceable to NIST, the percentage improvements are likely to at least give an idea of what his improvements might accomplish on another truck.

Yeah, I know, what a spoilsport... ;)

Blessings!

[Barry Nave]

Bulls99sub
Include a -TDC offset learn.

[Bulls99Sub]

Progress Report:
Factory exhaust is on the floor of the garage and 4 inch SS Diesel exhaust is on. Weather has not cooperated with follow-on testing, it has been to warm and very humid. Tonight looks promising though.
I am impressed with the SSDiesel exhaust. System is large and heavy - makes the factory system look like it came off a Yugo. Looks awesome on the truch, especially with the 5 inch polished tip. Directions were good, but non-specific to Suburbans. I ended up having to cut a little off the mid-pipe. Also had to re-engineer the mounts to fit into the factory rubber hangers.
Sound is awesome, like a big block on steroids. Nice to actually hear that the turbo is working. One thing to watch on the Suburban, make sure that the tip extends out past the side of the truck, or you get some reverberations up through the rear corner of the passenger compartment.
Like I said, have not had time to test, but the butt-o-meter is very happy. Truck actually feels like it has a top end surge. At least it sounds mean.

AndyL - Made a total of 6 runs to obtain the average time. Best runs were in the 11.3 range, worst was 11.6. Truck is completely stock with automatic and higher gearing - 3.73.
Moondoggie - exactly. There are many methods more accurate than the GTech but should indicate some measure of performance improvement.
Billman - May post numbers later, can't remember them off the top of my head. GTech figures are weight dependant, so I am trying to keep the same weight for each test sample. GTech says that their HP and torque numbers should always be lower than RWHP dyno numbers, because of actual road conditions - wind drag, etc.
Bnave95 - timing was one of the items that I would like to get to, need to find a good garage that will set it to my specs without giving me a hastle. BTW I was planning on a -1.50 setting since I use the truck primarily for towing and plowing.

More updates soon. Some will have to wait for the next several paychecks.

Bull

[Bulls99Sub]

Weather was good last night and I made some runs with the exhaust installed. After performing several runs, I was expecting a little more. However, I found a mistake in my baseline data where I forgot to include one of the runs. First comparison numbers are:
Corrected Baseline
0-60 11.43 sec
1/4 mile 18.24 sec at 76.6 mph
4 Inch Exhaust Installed
0-60 11.28 sec
1/4 mile 18.06 sec at 77.5 mph
Net Difference
0-60 -0.15 sec
1/4 mile -0.18 sec, +0.9 mph
As you can see, the exhaust helped some by itself. I expect a lot better results when other components are added that really allow the improved flow exhaust to shine. My prediction is that the computer will cut the most time, both from the increased power and improved shifting.
As far as the HP/Torque numbers go, I do not think that the GTech data is consistent. For some reason, the meter is now refusing to pick up the engine rpms. It was working fine for the first three baseline runs, then lost calibration. Torque readings are now all messed up and only have a few HP curves that look decent. Baseline best run was 143 HP, 317 torque. With the exhaust - 149 HP, not torque available. Posted for controversy, however, due to the quirkiness of the meter, not sure those numbers are reliable. GTech works much better on a gas motor.

Have a great day,

Bull

[rjschoolcraft]

Your 143 hp baseline is very close to what Kennedy has reported for a 97 Suburban from his SuperFlow chassis dyno. He reported 138 hp at the wheels on that truck with a gutted cat.

Your 317 lb-ft torque is close as well. Kennedy reported 326 lb-ft on the 97 that he tested. I would expect the 99 to actually be a little better than a 97 because of improved programming (the rating increased).

[Billman]

Nice job Bull.

Unfortunately, no controversy. You're numbers, as stated above, look pretty accurate.

Not exaggerated in the least...

You will begin to see, provided that you're G-meter stays accurate, that all of your modifications will work together as you add-on.

[Bulls99Sub]

Billman, that is the plan. I was expecting more of a kick from the exhaust, but I think it will let all the other mods do their job. I really expected the torque and HP numbers to be a little lower, since in car meters traditionally generate lower measurements than dynos. If I could just get the darn thing to sync better with the engine rpms...
Just picked up a 31x12x4 intercooler on ebay and plan to take the homemade IC route. I was thinking of doing the IC prior to the computer. Would it make a difference? Can the computer be programmed with the intercooler in mind? Thoughts?

Thanks, Bull

[Billman]

Reflashing the computer will not make a difference with/without Intercooler.

Best thing you can do to your truck is Intercool it. Benefits are endless...

If you have a scan tool hooked up while you test, and depending on how much boost you make, IC may help 0-60 times. Too much boost will create too much heat in the intake charge. At a certain point(230*-240*) the factory computer will cut back on your fuel, causing the truck to 'Lay Down'. If your mashing the throttle for ~11-12 seconds, IAT may be approaching the limit.

Intercooler cures all...

[matt-max]

picked up about 30hp (171-ish to 207-ish) with reprogrammed ecm and no other changes. original hp was about 130hp with L56 programming and stock. see my posts on tahoe performance testing over the past year and a half or so.

matt

[Bulls99Sub]

Hello all,

Sorry that things have been moving slowly, the weather has not been very cooperative and too busy running the kids around. I am ready for the next round of runs with a Green performance stock replacement air filter and a SSDiesel air intake system. Should have some data by the end of this long weekend. The intercooler should arrive today and may start the install this weekend also.

Have a nice Memorial Day Weekend and remember the past and current troops, Bull

[GMC Hauler]

OH OH OH!!!! Pick me pick me...

When I was doing the articles for Jim, I couldn't get my Gtech to pick up RPM's at first either. What you need to do is disconnect one of the batteries. The Gtech looks at the ripple generated by the alternator. The second battery provides too much "smoothing" for the Gtech to see the alternator. Just disconnect the negative post on the driver side battery, and it's that simple.
:D

I found the GTech Meter to be very consistent. I ran a minumum of 4 runs for each performance change, ran in each direction, and the data was very repeatable, most times to within the thousands of seconds. I still have all that data.

[Bulls99Sub]

Best runs so far yesterday evening. I was running with the 4 inch exhaust and a Green performance air filter.

Baseline (Stock)
0-60 11.43 sec
1/4 mile 18.24 sec at 76.6 mph
4 Inch Exhaust Installed
0-60 11.28 sec
1/4 mile 18.06 sec at 77.5 mph
Net Difference
0-60 -0.15 sec
1/4 mile -0.18 sec, +0.9 mph
4 Inch Exhaust and Green air filter
0-60 11.24 sec
1/4 mile 18.00 sec at 77.7 mph
Difference from Stock
0-60 -0.19 sec
1/4 mile -0.24, +1.1 mph

Last night I installed the SSDiesel intake system. Took a grand total of 15 minutes to install, including 10 minutes for taking pictures. It really cleans up the underhood look. I will post some pictures later. I found the stock plastic tube was deformed (mashed in) at end nearest the air filter - probably did not help the airflow. Will try to get in some runs tonight with the SSDiesel unit.

Also received the eBay intercooler, the thing is massive. I made brackets to hang it and mapped out the fittings and piping. It hangs a little lower than I would have liked, but snow plow brackets preclude mounting it higher. Can't wait to get everything hooked up.

Thanks, Bull

[Bulls99Sub]

My last update was actually from last week, but I could not get it to post at the time. SSDiesel intake system was installed and runs were completed. Wow, did the improved airflow make a difference. LOTS of turbo whistle at the front of the vehicle from the intake system and at the rear through the tailpipe. Anyway, here is the performance summary to date:

Baseline (Stock)
0-60 11.43 sec
1/4 mile 18.24 sec at 76.6 mph
4 Inch Exhaust Installed
0-60 11.28 sec
1/4 mile 18.06 sec at 77.5 mph
Net Difference
0-60 -0.15 sec
1/4 mile -0.18 sec, +0.9 mph
4 Inch Exhaust and Green air filter
0-60 11.24 sec
1/4 mile 18.00 sec at 77.7 mph
Difference from Stock
0-60 -0.19 sec
1/4 mile -0.24, +1.1 mph
4 inch exhaust and intake system
0-60 11.03 sec
1/4 mile 17.91 at 78.8
Difference from Stock
0-60 -0.40 sec
1/4 mile -0.33 sec, + 2.2 mph

But the best run was in the 10's for 0-60 (10.9) and 1/4 mile in 17.84.

Intercooler tubing and fittings are arriving daily, should all arrive by the weekend. So far, I have about $520 in the entire set-up and should have more than enough to complete the sytem. I have to have the intercooler on in less than 2 weeks for vacation.

Thanks, Bull