All I can say is wow! The last time I went to the track, it was mid 40's and my truck went 12.21 at 110. Today was 65 so I thought I would get some decent times. I just added a methanol injection kit to my truck and now I was getting 0 detonation and was able to run 20 degrees of timing up top where as last year I could only get about 19 to 19.5 during the 3rd gear pull! Best the truck ran today was 12.73 at 104.7 ......Pathetic.....

When I got home, I looked up the weather conditions for the track and it said 98% humidity, Pressure at 30.06in. It didn't feel like 98% humidity to me, but it has been raining lately so maybe so. I just can't believe my truck is off by 1/2 second especially considering I can now make a pass with more timing and no knock retard. Still more work to do with dialing in the truck (amount of meth sprayed, timing, etc) but is this normal? Are you forced inducted guys seeing this much drop from humidity and a little higher ambient temps?

Oh, and the 60's were normal (1.7's) for my truck.

 

What are you using for meth, and how was it tuned for?

 

AIS kit using a 50/50 mix (-20 Windshield Washer Fluid). He said it would make my air/fuel roughly .5 richer and he was right. I adjust my WOT table to adjust for that. I use HP Tuners. He may have me go to a higher Methanol vs Water concentration, but he wanted to see how we could do with the mix as it is more convenient for a street car and probably cheaper.

Last year without the kit, my IAT's would increase in the neighborhood of 52-57^ on a pass. Weather didn't matter as to the IAT increase during a run. My first pass yesterday with twin nozzles (7's), my IAT's increased 40^. 2nd pass I swapped one of the 7's for a 14 that I had and the IAT increase 30^. 3rd and final pass, I swapped in both 7 nozzles (now drilled out with a 1/16" drill bit (per his instructions) and the IAT increased 24^. NOTE: The orifice size of the drilled out nozzle was bigger then the 14 nozzle so I increased the flow quite a bit. He said I had to be careful with the water mix and sizing because if I get to big it will lose power and tend to bog when the kit activates.

He said straight methanol would require even bigger nozzles so I'm thinking he is going to have me go to even bigger nozzle sizes and potentially to a higher meth concentration....

For reference sake, my friend had a supercharged setup (TVS1900) and was off about 4 - 4.5 tenths from the May weather). On his log his IAT started at 100 and dropped to 82 by the end of the run. He uses straight Meth (Alky Controls kit).

 

IMO, that's too much water/ meth. Also, you should be able to go more than .5 degrees higher in timing with meth. Can't see your sig w/my phone, what's your setup?

 

Here is my sig:

04 SSS: GT2-3 cam, Volant CAI, 42lb green top injectors, Magnacharger with 2.8 pulley, Pacesetter long tube headers, 3" stainless exhaust, Magnaflow high flow cats, x-pipe and large stainless steel 70 series flowmasters, 2800 stall Circle D triple disc converter, Toy Shop 4L65-e with billet output shaft.

Best time to date 12.21 at 110 with 1.7 60 foot.

My kit is from AIS. I first seen information on them on "yellowbullet.com". There are a ton of extremely fast cars over there. Everything from bracket, to heads up to street racers and everything in between. Some very serious machines and some very knowledgeable people on there. AIS seemed to be very respected on the forum and many of the members had run his kists successfully with great results. That is saying a lot coming from the "bullet" as that can be a tough crowd over there. That is a big reason why I went with his kit over Alkycontrols kit.

Anyways, I was just following his recommendations and my IATS were coming down and my performance was picking up. No bogging or any signs of too much water at this point. I'm going to call him later today and see what he says.

As far as timing I wasn't trying to add timing at this point. My tune was already really aggressive (21^ degree range) but I had a lot of problems being able to make clean pulls last year (track) due to kr. As long as my IAT's were low when I started I could usually make a pretty clean run but I was pushing it. If the IAT's got too high, it would get some knock and pull the timing back down in the 19 - 19.5 range and the truck would slow down a bit. With the meth system (even at 160^ IAT), there isn't a hint of knock anywhere with that tune in it. I do plan to try more timing once I get things sorted out.

 

Yes, that high humidity will have a negative affect on your times.

Are you SD tuned?

 

No, still using the Maf.

 

Just going from everything I've researched & read, if you're spraying meth, you should be running in speed density, so that you can control your fueling.

Somebody please correct me if I'm mistaken.

 

Im not supercharged yet but... I can run a 15.2 in Tucson, I go to Phoenix an I'll run a 14.7. DA has ALOT to do with it. Check your DA for the fasted run then you last and see how they compare. Just my .02.

 

Im still running my stock MAF (not SD) on meth with no issues.

Just curious though, but did you put the Flowmaster on before or after your first run at the track? I ask because a chambered muffler will KILL hp on a FI motor. No joke here, but I had a single chamber Flowmaster on my truck when we dyno'd it the first time, and with no change at all to the tune, after we cut it off it made exactly 50 more rwhp.