Data Logs Stock vs Aftermarket intake

[RomanB]

I went to the race track a couple weeks back after I had my GT-350 intake installed and was pretty disappointed with the results. I ran a 12.1 at 115 which was on line with what I was running pre manifold/intake install (stock exhaust) Something was not adding up. Car was not making the power it should be making.

Only thing i could track it down to was the brand "I" intake, and after doing some data logging I was shocked on how much power it wasn't making. The stock intake with a panel filter and Airaid MIT tube made 4-6lbs/min more pretty much everywhere in the power band in the same D/A (3800ft). I data logged both setups several times just to make sure the data was consistent.

I was looking for a closed box setup to keep the IATs down, just going to stick with the stocker for now and go back to the track and hope for a better E/T and trap. I attached the logs

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[4V Mayhem]

Brand "I"? Injen??

 

[RomanB]

Brand "I"? Injen??

Yes, and I don't know why my logs didn't upload

 

[RomanB]

forgot to zip them

 

[Sasuketr]

I was thinking about getting this injen system back in the day but now i have my buddies airaid mit and afe pro dry s filter. I really like this combo. Regarding your lb/min comments. I had the same issue with just the tune! You can look at my thread regarding lund flex fuel. When i compared the tune results to stock i saw the flowrate lb/min being little bit higher in stock than the tuned version. I received a response from lund regarding this. They said, they do control that parameter and it doesnt reflect the real airflow rate. So if you are also tuned, it might be related to that.

I will be testing the mishimoto tube in couple of weeks as well!

 

[RomanB]

Correct me if I am wrong but if you factor in the short term fuel trims then it is accurate? But after talking to Lund they said if I tested the intakes on the exact same tune and one flowed less LBS/min it was an accurate test.

 

[GTBOB]

Same thing happened to me when I initially installed the INJEN. My maf reading were low. LUND took at look at my tune. After about 3 revisions, the numbers came back up. I have a thread about this. Other than that small hiccup, I like intake.

 

[RomanB]

Same thing happened to me when I initially installed the INJEN. My maf reading were low. LUND took at look at my tune. After about 3 revisions, the numbers came back up. I have a thread about this. Other than that small hiccup, I like intake.

Wasn't your MAF function off because of switching from the roush and that's why you had lower numbers? It is literally 4-6 lbs lower everywhere... with allegedly the same MAF diameter

 

[GTBOB]

I had the insert removed from the Roush (larger opening) when I hogged out the INJEN. I believe the Roush is 105mm with the insert out (can't remember)? There was still a mismatch in size between the two causing the low maf counts with the INJEN.

 

[SVT Wylde]

Something isn't adding up because the Injen can't be that bad. It has more surface area than the stock filter, a smooth elbow like the MIT, and GTBOB isn't having any problems. Have you asked Lund to do a revised tune?

I just installed one on my stock car and driveability is just like stock but with better throttle response. I had high hopes for this intake so I hope it doesn't turn out to be a POS.

 

[RomanB]

I don't know why the tune would need to be revised for a non tune intake... If you look at the logs it's plain as day, it isn't flowing as well. I suspect there is a shit load of turbulence between the filter being in the is irked path then it hits a 90 degree turn then a coupler, then the MAF is at the very end of the insert which doesn't make sense to me. I had I hopes too

 

[redtrack]

I have the Lund tune with the Injen intake. The insert removed is 106.6 mm
ID. @ 7k is reading 41-42 lbs. It's low or it's OK?

 

[markmurfie]

You need to look at your fuel trims. With the injen intake they are not as far off as with the stock intake. This is expected if the tune was made for that intake. the ltft is the long term and the stft are the short term. they should both be 1 at all rpms. the long term is the ecu compensating for learned trims from the short term. the short term is compensation for quick changes in environment. If you add these up you will get how much your ecu is correcting fuel. from your logs it looks like the injen has learned about -5 to -7% and the short term is with in a few %. Your stock intake it has learned -15% and is still removing -4 to -5%. if you factor this in to your MAF value you will get your real MAF value. injen peaks around 38lb/min minus 7% you get a little over 35 lb/min. stock peaks around 44lb/min remove a conservative 19% you get around the same 35lb/min. Factor in the Air charge difference both intakes are flowing the same. I would stick with the injen just to not have the ECU be compensating so much. I would also send some data logs in with the injen to see if they could get it dialed in more.

 

[RomanB]

You need to look at your fuel trims. With the injen intake they are not as far off as with the stock intake. This is expected if the tune was made for that intake. the ltft is the long term and the stft are the short term. they should both be 1 at all rpms. the long term is the ecu compensating for learned trims from the short term. the short term is compensation for quick changes in environment. If you add these up you will get how much your ecu is correcting fuel. from your logs it looks like the injen has learned about -5 to -7% and the short term is with in a few %. Your stock intake it has learned -15% and is still removing -4 to -5%. if you factor this in to your MAF value you will get your real MAF value. injen peaks around 38lb/min minus 7% you get a little over 35 lb/min. stock peaks around 44lb/min remove a conservative 19% you get around the same 35lb/min. Factor in the Air charge difference both intakes are flowing the same. I would stick with the injen just to not have the ECU be compensating so much. I would also send some data logs in with the injen to see if they could get it dialed in more.

I data logged quite a few more times and the STFT for the stock intake were almost perfect and flowing 45lbs/min. Trapped 2mph faster with the stock intake and tube then with the Injen. Air was slightly better but not by much. I Datalogged the Injen and the stock intake multiple times and factored in the fuel trims. Stock intake came up on top. Tune was made for a stock MAF diameter. I don't know what you would change in a tune between one intake and another with the same MAF diameter. LTFT on Lunds FF tune will never be close to being right. It is off because of the calculations being done to compensate for e85. Sold the Injen.

 

[GSLSE20B]

Correct me if I am wrong but if you factor in the short term fuel trims then it is accurate? But after talking to Lund they said if I tested the intakes on the exact same tune and one flowed less LBS/min it was an accurate test.

I run 11.0s at 124-125 with 43-46 on my datalogs . The tune ignores the maf at WOT . I can make it show 3lbs/min or 70lbs/min and my fuel trims will still be zero . The only time it will matter is if you change something else that allows the airflow to increase using the same maf period table .

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