Looney Tuning
05-26-2009, 03:13 PM
This Evo X GSR belongs to mrdeluxe86. It had the following modifications:
HKS Exhaust
HKS Downpipe
HKS intake
HKS hard pipes
HKS BOV VTA
The two main parts that I did not like were the VTA BOV and the HKS intake.
It is well known that a VTA BOV is problematic on an Evo, especially the Evo X. I told the owner to swap back to the stock BOV, but he insisted on keeping the VTA BOV. Well, the VTS BOV triggers a p1241 code and the car goes into limp mod because of it. It is possible that the code would be eliminated if the BOV is re-circulated, but I am not sure of that. The best option here is to swap back to the stock BOV.
The HKS intake is also of a poor design. It sits in the engine bay right behind of the radiator fan w/o any heat shield. Just take a look at this picture and see for yourself.
http://www.sr20deracing.com/EVO/Tommy/HKS_Evo_Intake.gif
Predictably the intake failed to reduce the IATs much. Here are the average IAT numbers for the intake as logged on 3 WOT 4th gear logs:
http://www.sr20deracing.com/EVO/Tommy/hks_iat.gif
The average IAT starts at ~91* F and ends at ~89* F, a slight decrease of 2* F. By contrast, the stock intake is capable of reducing IATs, by 6* F during a 4th gear WOT pull. I have been collecting IAT data on several drop-ins and intakes and I will soon do a write-up on my findings. As a sneak preview, the intake that lowers IATs the most has been the Injen.
It is also common to expect the AFR to go leaner with an intake, but that is the not the case with the HKS. HKS probably used a MAF housing that is the same size as stock and this prevented the AFR from leaning out. The AFR was incredibly rich on this car. It basically flat lined the Zeitronix meter at 9.6:1. I never knew that the ZT2 does not go below 9.6:1. I would have loved to test with the LM-1 to see the richness of the AFR on this car. FWIW, here are the results of the stock AFR and the tuned AFR.
http://www.sr20deracing.com/EVO/Tommy/afr_b4_after.gif
The tuned AFR was much leaner than the stock one. I do not know by how much since the AFR meter flat-lined. I set the AFR in the mid 11s at peak and then slowly tapered it to 11:1 by redline.
The stock boost on this car was also on the low side of things. First, boost peaked at 21 psi at a rather late 4500 rpm and then tapered to peak of 15 psi by redline. By contrast, the tuned boost peak 1000 rpm higher at 24-25 psi and held to 18.8 psi by redline. This was 4-5 psi higher at peak and 3.8 psi higher by redline.
http://www.sr20deracing.com/EVO/Tommy/boost_b4_after.gif
The airflow numbers on the car also improved. While peak airflow at 3500 rpm was ~20 lb/min on the stock tune, it improved to ~ 23 lbs/min on after the tune. The all important redline airflow improved by 3.4 lb/min to 38 lbs/min. Some estimate that the limits of the stock turbo is reached at ~40-42 lbs/min.
http://www.sr20deracing.com/EVO/Tommy/airflow_b4_after.gif
Given the leaner AFR and the higher airflow numbers from stock, the gains in the power curve were very impressive.
http://www.sr20deracing.com/EVO/Tommy/dyno_b4_after.gif
As noted on the chart the highest to lowest gains were as follows:
Maximum gain of 60 hp @ 6670 rpm
Maximum gain of 51 ft-lb @ 3830 rpm
Peak gain of 43 hp
Peak gain of 39 ft-lb
Minimum gain of 18 hp @ 4500 rpm
Minimum gain of 9 ft-lb @ 4700 rpm
I have been in contact with the owner of the car and he has wisely decided to get a re-circulation kit for the BOV. After he installs it, I will re-log the car and see if there are any adjustments needed for the tune.
HKS Exhaust
HKS Downpipe
HKS intake
HKS hard pipes
HKS BOV VTA
The two main parts that I did not like were the VTA BOV and the HKS intake.
It is well known that a VTA BOV is problematic on an Evo, especially the Evo X. I told the owner to swap back to the stock BOV, but he insisted on keeping the VTA BOV. Well, the VTS BOV triggers a p1241 code and the car goes into limp mod because of it. It is possible that the code would be eliminated if the BOV is re-circulated, but I am not sure of that. The best option here is to swap back to the stock BOV.
The HKS intake is also of a poor design. It sits in the engine bay right behind of the radiator fan w/o any heat shield. Just take a look at this picture and see for yourself.
http://www.sr20deracing.com/EVO/Tommy/HKS_Evo_Intake.gif
Predictably the intake failed to reduce the IATs much. Here are the average IAT numbers for the intake as logged on 3 WOT 4th gear logs:
http://www.sr20deracing.com/EVO/Tommy/hks_iat.gif
The average IAT starts at ~91* F and ends at ~89* F, a slight decrease of 2* F. By contrast, the stock intake is capable of reducing IATs, by 6* F during a 4th gear WOT pull. I have been collecting IAT data on several drop-ins and intakes and I will soon do a write-up on my findings. As a sneak preview, the intake that lowers IATs the most has been the Injen.
It is also common to expect the AFR to go leaner with an intake, but that is the not the case with the HKS. HKS probably used a MAF housing that is the same size as stock and this prevented the AFR from leaning out. The AFR was incredibly rich on this car. It basically flat lined the Zeitronix meter at 9.6:1. I never knew that the ZT2 does not go below 9.6:1. I would have loved to test with the LM-1 to see the richness of the AFR on this car. FWIW, here are the results of the stock AFR and the tuned AFR.
http://www.sr20deracing.com/EVO/Tommy/afr_b4_after.gif
The tuned AFR was much leaner than the stock one. I do not know by how much since the AFR meter flat-lined. I set the AFR in the mid 11s at peak and then slowly tapered it to 11:1 by redline.
The stock boost on this car was also on the low side of things. First, boost peaked at 21 psi at a rather late 4500 rpm and then tapered to peak of 15 psi by redline. By contrast, the tuned boost peak 1000 rpm higher at 24-25 psi and held to 18.8 psi by redline. This was 4-5 psi higher at peak and 3.8 psi higher by redline.
http://www.sr20deracing.com/EVO/Tommy/boost_b4_after.gif
The airflow numbers on the car also improved. While peak airflow at 3500 rpm was ~20 lb/min on the stock tune, it improved to ~ 23 lbs/min on after the tune. The all important redline airflow improved by 3.4 lb/min to 38 lbs/min. Some estimate that the limits of the stock turbo is reached at ~40-42 lbs/min.
http://www.sr20deracing.com/EVO/Tommy/airflow_b4_after.gif
Given the leaner AFR and the higher airflow numbers from stock, the gains in the power curve were very impressive.
http://www.sr20deracing.com/EVO/Tommy/dyno_b4_after.gif
As noted on the chart the highest to lowest gains were as follows:
Maximum gain of 60 hp @ 6670 rpm
Maximum gain of 51 ft-lb @ 3830 rpm
Peak gain of 43 hp
Peak gain of 39 ft-lb
Minimum gain of 18 hp @ 4500 rpm
Minimum gain of 9 ft-lb @ 4700 rpm
I have been in contact with the owner of the car and he has wisely decided to get a re-circulation kit for the BOV. After he installs it, I will re-log the car and see if there are any adjustments needed for the tune.