This is a repost of the final results. I will keep all existing information so you can follow the thread feedback and analysis.
I just got back from the shop after about an hour and a half of tuning. And here is the verdict...
The M370 intake manifold made more power than the stock manifold from 2,000 rpm all the way to 7,000 rpm. After 7,000 rpm, it was neck and neck. I just sold that damn manifold too... Guess I'll be getting another one down the road.
What all this doesn't explain is how I lost 10whp and tq after a tune from 30 march till now. I'm thinking there is something else that's going on with this car. I'm not sure if it's the sensor, or spark plugs, or both. Posted below are the dyno graphs.
Keep in mind my tuned numbers are lower than my untuned numbers. It's a$$ backwards I know, I'm trying to figure out why.
Information on the graphs isat the top of the image (Fixed Graphs)
1st graph is the stock manifold and the M370 (Blue is M370)
2nd graph is the same but displaying AFR's (Red is M370)
3rd graph is Stock tuned and stock untuned results (Blue is tuned, red is untuned)
4th graph is the same but showing AFR's (Blue is tuned, red is untuned)
5th graph is the M370 manifold tuned and untuned (Blue is tuned, red is untuned)
6th graph is the same but showing AFR's (Blue is tuned, red is untuned)
__________________________________________________ __________________________________________________ __________________________________________________ ___________________________________
Original Post
I decided to make this seperate from my old thread (
LTH with HFC + CBE = ?)on my mods as I think this is pretty relevant and stand out.I finally tuned my car and as many of you have known, Ive been having some irritations with it. After months of trying to track down whats causing me to run super rich and rob power, I tracked it down to a bad precat O2 sensor. I replaced it last week and with it working again, it was possible to tune.So I went to the shop (Force Fed Racing in Las Vegas) around midnight with a 6 pack of Sam Adams Summer Ale, a couple laptops, and my Uprev tuner cable.
Mods on my vehicle are on my sig, but I'll list them here: I have PPE LTH's, a Motordyne XYZ Y pipe with a high flow catalytic converter, Tanabe Medallion exhaust, NST crank and alternator pulleys, AEM cold air intake with ETI module, and AE Performance Oil cooler. My oil temps never broke 185 during the runs I might add...
I strapped on the rollers (Dynojet) around 1:30 in the morning after the previous car unstrapped and cleaned his puddle of transmission fluid he left. After Johnny (Shop Co-owner) got familiar with the software, we did a baseline. 280whp and 225 lbft tq. WTF. It was running 11:5 1 AFR's through the run. If you look at my sig below, that's what the car made with the stock manifold and untuned. Untuned, AFR's were in the low to mid 13's most of the run. After about two hours of tuning, we added a couple points of fuel between 3200 and 3600 rpm and one point at 4k rpm because it was too lean, We took fuel out over 5k rpm, and reduced timing by 3 degrees. AFR's were around 13.3-13.4 throughout most of the run and the power curve smoothed out. We were able to get power back up to 304 whp and 243 lb ft tq.
Compared to my last run, I was able to get most of the torque back, but I'm missing a lot of power on the top end. After 5k rpm, I'm not making as much as I did with the stock manifold. This leads me to believe that the stock manifold is better than the M370 when full bolt on's are on the vehicle. Both the intakes and headers really opened up power after 6k rpm and the M370 is the limiting factor. For a near stock vehicle, I see no issues with the M370, but for my car, I did not see a bump in midrange power and I saw a dramatic loss up top when compared to the stock manifold. I'll be removing the M370 and replacing the stock manifold soon and I'll be back on the rollers to retune the vehicle with the old manifold.
I'm not here to bash on Motordyne's products, I really like their stuff, but the M370 did not work for me. I was a M370 faithful and stood by in it's defense until I could prove whether it worked for me or not. I'm disappointed in the results, but the dyno doesn't lie. All my runs have been on the same dyno since baseline. The only differences is temperature. It was about 85 degrees last night. I'm at work and don't have the dyno run on me, I'll post when I get home. Maybe someone might be able to explain the significant power difference until then.