•TECHNICAL•

4G63 Camshaft Testing

Project Description:

The scope of this project is to test a series of camshafts and their effect on horsepower and torque on the Mitsubishi 4G63 turbo engine. The test was conducted on a Dynojet Model 248 in-ground dynamometer. Horsepower and Torque figures shown are SAE corrected with graph smoothing at level 3. The boost level was set to 19psi, but as the turbo came on boost it would spike to roughly 23psi and then fall off to 19psi as the RPM's climbed. This boost spike can be seen by looking at the torque curves. Each test was run 4 times with a 5 minute cool down time between runs and the engine was at full operating temperature. Each run was logged to make sure there was no or little knock and that ignition timing was consistent between runs. I looked at the average of all the runs for a specific camshaft and chose a run that was a fair representation of it's performance.

Test vehicle:

• 1994 Eagle Talon - 5spd
• 1991 Motor with roughly 40K miles, stock bottom and top end including head gasket
• Turbo: 16G with ported exhaust housing
• Exhaust Manifold: 2G ported
• Intake Manifold: Stock
• Throttle Body: Stock
• MAF: 1G slightly hacked (screw backed out) with K&N filter & stock turbo intake pipe
• Intercooler: Spearco 2-221 core with custom mandrel bent 2.25" diameter piping.
• Exhaust: HRC O2 eliminator downpipe and 3" exhaust with no cat-conv.
• Injectors & Fuel Control: Walbro 255lph Fuel Pump, 510cc/min injectors & S-AFC
• Boost controller: Ric Gillis Manual boost controller, check ball & spring type.
• Gas: 100 octane unleaded
• Ignition: Stock with NGK BPR7ES plugs, timing set to stock specifications

Cams Tested

• Stock Mitsubishi
• Web Cams - Street Grind
• HKS 264 Intake 264 Exhaust
• HKS 264 Intake 272 Exhaust
• HKS 272 Intake 272 Exhaust
• Crower - Stage 3 Grind
• Jun Stage 3 Grind

Peak Horsepower and Torque Results

Stock Mitsubishi Camshafts
Peak HP: 309.5
Peak TRQ: 295.3
Spool up on street: quick, full boost by 3.2K RPM in 3rd gear with good power when off boost and as it's coming onto boost.

Web Cams - Street Grind
Peak HP: 314.3
Peak TRQ: 295.3
Spool up on street: slower than stock, full boost by 3.4K RPM in 3rd gear with less power off boost than stock cams.

Crower - Stage 3 Grind
Peak HP: 322.6
Peak TRQ: 314.0
Spool up on street: much slower than stock (the worst of all the cams) with full boost hitting by 3.6-3.7K RPM and a definite loss in power off boost compared to stock cams.

Jun Stage 3 Grind
Peak HP: 323.7
Peak TRQ: 323.2
Spool up on street: Car was not driven on the street.

HKS 264 Intake 264 Exhaust
Peak HP: 323.1
Peak TRQ: 333.0
Spool up on street: As good as stock (3.2K RPM), with off boost power the same if not better than stock.

HKS 264 Intake 272 Exhaust
Peak HP: 324.2
Peak TRQ: 333.1
Spool up on street: Slightly slower than stock (3.3K RPM in 3rd gear) and a very slight loss in power in off boost conditions.

HKS 272 Intake 272 Exhaust
Peak HP: 325.2
Peak TRQ: 323.4
Spool up on street: Slower than stock, full boost by 3.4K RPM in 3rd gear with a slight loss in power in off boost conditions.

Dyno Graphs

Stock Vs. Web Cams
Stock Vs. Crower Stage 3
Stock Vs. Jun Stage 3
Stock Vs. HKS 264 In 264 Ex
Stock Vs. HKS 272 In 272 Ex
HKS 264 In 264 Ex Vs. HKS 272 In 272 Ex
HKS 264 In 264 Ex VS. HKS 264 In 272 Ex
HKS 272 In 272 Ex VS. Crower Stage 3
HKS 272 In 272 Ex VS Jun Stage 3
HKS 264's VS HKS 272's VS Crower Stage 3 VS Jun Stage 3

Conclusion

We reached the limitations of the 16G turbo during this test. The turbo would not make any more power nor would it hold more than 20psi of boost at higher RPM's. When the boost was turned up to 25psi the torque went to 350ft-lbs (HKS 272's) but the boost again would fall to 20psi and only make 327whp. From the dyno graphs it appears that for the best track times the HKS 272's would be the best choice. With a larger turbo choice (T3/T4) I think the difference in high RPM horsepower would be more apparent and would reflect better on the more aggressive camshafts. Time permitting we might run a test between a few of these camshaft on car with a larger turbocharger. In the meantime we'll be installing an FRH intake manifold and less restrictive intake tract on the 16g powered test car to see if we can squeeze a little more airflow out the little guy. For any questions or comments feel free to contact us at the shop (847-709-0530).

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