500 efi. Hp question
11-13-2018 | 06:01 PM
#1
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From: Punta Gorda
500 efi. Hp question
The early 500 EFI s 2000 2001 where rated at 470. Now didn’t merc get some flack for not being 500 hp . And on the later models bump it up to 500 hp with a computer upgrade ?
11-13-2018 | 06:23 PM
#2
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From: Merritt Island, FL
It depends on where you measure. At the prop they say 470.
Mine on the dyno with everything on them, water pump, sea pump, wet exhaust etc, corrected were right at 507-511HP.
This was at 380 ish hours, top ends had been rebuilt around 320-330.
EDIT: Mine are 2000, electric fuel pump only model.
Mine on the dyno with everything on them, water pump, sea pump, wet exhaust etc, corrected were right at 507-511HP.
This was at 380 ish hours, top ends had been rebuilt around 320-330.
EDIT: Mine are 2000, electric fuel pump only model.
Last edited by Wildman_grafix; 11-14-2018 at 07:03 AM.
11-13-2018 | 10:15 PM
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From: Ft. Worth TX
the carb HP 500 and the 500 HP EFI both were 470 hp and the EFI had the E top headers,
nothing special about that EFI set up and MEFI 3 and 1989 Multec fuel injectors, plus bank (batched) fired for making any added power. Wonder if the carb 500 would have made more power than the 500 EFI if it had installed CMI E top headers also ??. I understand they are short runners for the E tops so they give up some but the GILs were not no powerhouse plus they reverted water.
Back in the day I guess it was fairly good but PCM 555 was out in late 2000. If I recall correctly the 500 HP EFI ended at the end of 2003. Maybe early 2004 ??
nothing special about that EFI set up and MEFI 3 and 1989 Multec fuel injectors, plus bank (batched) fired for making any added power. Wonder if the carb 500 would have made more power than the 500 EFI if it had installed CMI E top headers also ??. I understand they are short runners for the E tops so they give up some but the GILs were not no powerhouse plus they reverted water.
Back in the day I guess it was fairly good but PCM 555 was out in late 2000. If I recall correctly the 500 HP EFI ended at the end of 2003. Maybe early 2004 ??
11-14-2018 | 07:13 AM
#7
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From: Merritt Island, FL
Here are dyno numbers from totally stock HP500EFI and a stock 525. Same dyno, yes different years but interesting when you look at the curves. I should put into a spreadsheet and make a curve.
Also note this was before the injectors were cleaned and flowed on the 500's.
Last edited by Wildman_grafix; 11-14-2018 at 07:18 AM.
