10mm_

I recently added an AFE CAI and ARH catless mid length headers to my car, and to be honest the performance results from both were rather underwhelming. (The sound is great)









I really didn't put too many miles on the car with the 2 mods and no tune, so it's possible that the computer would have "learned" a little but I figured that since I got the P0420/0430 code for no cats I might as well move forward with a tune and take full advantage of the mods (plus it should be safer).


I took the car to the drag strip in some pretty hot/nasty weather last night to get an idea of how much I picked up from the two mods plus how much additional I would pick up from the tune. I will have to drive 150 miles with the Diablo tune loaded before I can get my Diablew tune done so I will report those results when I get them.

Just a little FYI the physical elevation of this track is 100', so in my experience you don't really run "good" times here until the DA is under 500, I have raced at 3 other nearby tracks and they are all .2 or .3 faster for a given DA. It's a bit of a slow track and it's even slower in hot air. My previous best time here was 11.90@117.2 back in March when the DA was 473' (and my 60' on that pass was 1.88).



I ran my car at this track on 7/24 and the DA was 1477', I went 11.92 @ 115.3 with a 1.81 60'.

The first pass I made last night I will disregard for 2 reasons, one being I tried to do a minimal burnout to save my tires and I ended up spinning badly, and two being the mph readout was broken in that lane so I only got ET no MPH. I switched to the right lane for all subsequent runs.

The second pass I made after letting my car cool off for 45 min was 11.87 @ 117.99, 1.87 60' and the DA was 1663'. Comparing that to the time from a month ago that's a decent gain in mph, but not much ET. The 60' was a little worse so that could account for the ET not being there.

I originally wanted to make 2 passes stock tune and then a couple on the diablo tune to get a good average but I didn't know how many passes I would be able to get in so I went ahead and loaded the Diablo tune for my 3rd run. That run was 11.79 @ 118.23 with a 1.82 60' and the DA was 1644'. Basically no difference since my car was capable of that 60' anyway I was just adjusting my launch RPM based on how sticky the track was, and .24 mph is well within the margin for consecutive passes anyway. (and the DA was slightly better)


I let my car cool for an hour and a half this time, I wanted to see if I could hit an 11.6. I launched it as hard as I thought the track would hold, and I guessed a little too high, the car spun badly and went 12.16 @ 118.45 with a 2.06 60'. The DA was 1592 for that pass.


Frustrated and anxious to see if the heat was really a factor anyway, I drove my car down the return road straight back into the staging lanes where I was second in line to go again, I waited about 30 seconds for my turn and I hot lapped the car to see if a little better burnout and a couple hundred rpm less on the launch could get me one last decent pass before I went home. 11.73 @ 118.80 on a 1.80 60'. Same DA of 1592 obviously.


My take on all that? I'm actually pretty happy with the results, especially since I made my best pass of the night hot lapping the car. If you have been racing a long time like I have you get a feel for what causes what at a drag strip, I've made hundreds and hundreds of passes so I'm used to taking all the factors into consideration knowing that it's not easy to run a car "back to back" and compare a mod or a change. It's also not easy to add 3-4 mph to a car that already traps above 115. 5 or 10 hp won't do that. Just so you guys know that i'm not kidding about how slow the track is in this heat, there was a Hellcat there that made several passes, he trapped 120 just about every time, and he was driving the car pretty well. Another guy had an auto 392 Challenger (stock) and he was consistently 110 mph. Plenty of modded 5.0 coyote mustangs were around 110-111 mph.

I don't feel like the Diablo tune added a whole lot but I didn't expect it to either. I will say that it seemed like the car picked up a little each pass even though the air wasn't really getting that much better, It made me curious to drive the car for a couple hundred miles and then go back and make a few more passes. I can also say that I know what everyone else is talking about now, as far as part throttle street driving I only felt the tune for the 5 mile drive home from the track and it is NIGHT AND DAY different than stock. It feels like it has a ton more torque right where you want it, the idle quality is good and it's not jerky or harsh it's simply fantastic. Diablo isn't kidding that the tune feels way way better, it does. It just didn't really make the car much faster at WOT, which is why the dyno results look the way they do.


I really just want to make sure that the tune is "appropriate" or correct if you will. That's why I plan to go the extra step and have Lew review the data logs and make sure everything is correct. I didn't get a CEL while I was racing or on the way home from the track, not sure if it will come back or not now that I have the 93 octance AFE tune loaded.

Sorry for the long winded post, I hope this helps people who are thinking about going with the tune. I will update this thread as I go back to the track in cooler air, and get more miles on the car as well as load the Diablew tune.

marcouvo

Thanx for the informative post.

That was some real poor air for sure. Look forward to your results in cooler, drier air.

Are you planning to dyno after the new tune? If so, hope you wait on some better air for that as well.

Higgs Boson

I would love to have a track at 100 ft and your DA.....why I don't run the Corvette in the summer - last weekend DA at my track was 4000+ ft. Horrible. Although I did run my race car. ;-)

10mm_

The track I always ran at back in Ohio was 1200' physical and if the DA was 2500' I could run faster there than I do here if the DA is 1500'.

I ran at Richmond one week after my 11.90 pass here in March and went 11.52@119.5 bone stock. I can't wait to go back there in the fall on spray

REDBULLIT

Great write up 10mm, I was waiting on your thoughts, I'm sure it will do so much better once the weather cools down.

Fore58

Could you say there was at least a .2 ET improvement from the last time you went at this same track with similar conditions? It shouldn't be so overwhelming later on this years with better drag racing weather. Great help for the ones that desire similar mods. Nice write up, 10mm.

Mike Campbell

Actually considering the heat & humidity your times are pretty good. The questions I have is did you use the Nitrous on these runs? And, was it difficult to tune? I've read a ton of forum posts stating that the Diablo tune does more for the car than the CAI and headers. What do you think?

marcouvo

I'm starting to think from these results and others (dynos) most of the gains are with the tune and filter, when adding headers, CAI, and a tune on a stock motor NA C7.

But that might not prevent me from adding a CAI and ARH mid-length headers with cats.

0TPR

We noticed exactly 30whp on our (at the time) Stock C7Z. The AFR's were so scary at WOT that we felt the AFE needs to be installed and a manditory tune was in order.

we picked up 45whp with our tune (stock everything). Then we added the AFE (on the same day) as part of of our stg1 package and noticed a 5whp gain. Now I was disapointed so I flashed the car back to stock and made a pull with intake only and thats when the 30whp gain was achived. But it leaned the motor out to the point at around 4400-redline i was cringing but needed to follow threw with the pull. I can only imagine what your engine is doing with NO tune with Intake and long tubes. Have you since tuned the car?

Rob-

Fore58

Tune and green filter may be the best start.....easy bolt ons. Headers can always come later. I have seen a set up with only a tune and air box mod with a trap speed of 122.... M7. Check the fast list, the car is there. And I was there when the pass was made.

10mm_

My best estimate is that it picked up .25 on the ET and 3 mph.

10mm_

No nitrous on these runs.


CAI and headers add way more WOT performance than the Diablo tune.

Oh and the Diablo is very easy to load.

10mm_

A C7Z is completely different than my car, not sure how results from that would be applicable.


I don't have long tubes, I have mid lengths.

Also I stated in my post that I did tune the car after the second run. Although it didn't make much of a difference in ET or MPH

10mm_

It's not that easy to compare trap speeds at different tracks in different weather. I've been 119.5 bone stock so I'm confident my car would be better than 122 under the same conditions.


This trip to the track was to see the difference not run a great number. That will happen in the fall.


It's just like a Dyno

Fore58

My best so far is 11.88@118.3 at Bradenton Florida track. If go out in this horrible weather I will be lucky to get 12.50s. I fully understand your point.

marcouvo

Thanx, I got a Air-Raid filter and a Trifecta tune. The car runs much better/stronger under partial throttle since. I don't race and very rarely get to WOT on the street.

xp800

10mm, great write up. Curious to see what you're getting for LTFTs while logging with the canned aFe DS tune vs. what Lew eventually sends back. Did you add throttle boost?

10mm_

Exactly lol.

I honestly believe it would have run a high 11.6 on the next-to-last pass if it had hooked, probably at 119.x.

That's essentially picking up almost .3 and over 3 mph in worse air, I'm totally good with that lol.


I'm hoping for 11.4 in good air, even better if I run at Richmond again. And then deep into the 10's on spray.

10mm_

I can check them if you guys want, I haven't done any data logging since loading the canned tune.

I did not add any throttle boost at all, just loaded the canned tune the way it came.


If there is anything to be gained from having some miles on with the tune it will only get better.

Also I am convinced that adding a little octane to these cars helps, especially with the way the ECU will throw timing at it. When I ran the 11.92@115 I had over 100 octane fuel in the car, this past Friday it was just on pump 93. 1/2 tank of it at that. I just can't wait for that cool fall air lol I'll have all my ducks in a row.

VNAMVET

That makes two of us....