majorlag
Elite Explorer<br><img src="/forums/images/stars4.
- Joined
- July 31, 2002
- Messages
- 252
- Reaction score
- 0
- City, State
- Knoxville, TN
- Year, Model & Trim Level
- 1994 XLT 4x4
Hey guys!
Just wanted to post some info for anyone with questions about horsepower/torque gains from bolt-on engine mods and chip upgrades. This past weekend I had my Ex dyno tested with an air-fuel ratio check (just to satisfy my gnawing doubt). This is an original 4.0 OHV with 98k+ on it, no towing, pretty regular maintenence, with a fairly new rear main seal (long story). Otherwise, tip-top shape. Stock numbers at the flywheel were 160 HP @ 4200 RPM and 220 FT-LB @ 3000 RPM. With assumed drivetrain losses of about 30% (25% for auto tranny and 5%? for transfer case and diffs), this leaves 112 HP and 154 FT-LB.
My mods include (see sig at bottom):
63mm TB
70mm MAS
Apten 93 Performance Chip
KKM Intake
Flowmaster exhaust
4.10 Gears
Results (at the wheels):
127 RWHP @ 4200 RPM (approx. 181 HP at flywheel)
200 FT-LB @ 2700 RPM (approx. 285 FT-LB at flywheel)
My approximations are based purely on assumed 30% losses and do not reflect actual calculations. Also, the shop had never tested an Ex before and had some difficulty, so some pulls were performed in 1st or 2nd gear only and some were in drive.
Conclusion:
All my modifications cost about $1500
, so that's about $71/HP or $17/FT-LB. Not very cost-effective. Superchargers run about $3500 (assuming professional installation), and may yield 80ish HP, or $43/HP. This requires, however, a big pile of cash at one time, which is why I didn't go that route.
Measureable numbers may not be that impressive, but the perceived power and improved driveability are very noticeably. I am pleased with the results, and would recommend these or similar modifications.
Just wanted to post some info for anyone with questions about horsepower/torque gains from bolt-on engine mods and chip upgrades. This past weekend I had my Ex dyno tested with an air-fuel ratio check (just to satisfy my gnawing doubt). This is an original 4.0 OHV with 98k+ on it, no towing, pretty regular maintenence, with a fairly new rear main seal (long story). Otherwise, tip-top shape. Stock numbers at the flywheel were 160 HP @ 4200 RPM and 220 FT-LB @ 3000 RPM. With assumed drivetrain losses of about 30% (25% for auto tranny and 5%? for transfer case and diffs), this leaves 112 HP and 154 FT-LB.
My mods include (see sig at bottom):
63mm TB
70mm MAS
Apten 93 Performance Chip
KKM Intake
Flowmaster exhaust
4.10 Gears
Results (at the wheels):
127 RWHP @ 4200 RPM (approx. 181 HP at flywheel)
200 FT-LB @ 2700 RPM (approx. 285 FT-LB at flywheel)
My approximations are based purely on assumed 30% losses and do not reflect actual calculations. Also, the shop had never tested an Ex before and had some difficulty, so some pulls were performed in 1st or 2nd gear only and some were in drive.
Conclusion:
All my modifications cost about $1500

Measureable numbers may not be that impressive, but the perceived power and improved driveability are very noticeably. I am pleased with the results, and would recommend these or similar modifications.