4.8 Injector sizing... e85 worth it?
Thread Starter
Teching In
Joined: Oct 2023
Posts: 3
Likes: 0
4.8 Injector sizing... e85 worth it? I have a 2001 RCSB with a 4.8 5sp and it currently only has long tube headers. I'm getting ready to purchase an HP tuner and to put a BTR Truck Norris cam with upgraded springs and possibly a larger throttle body/CAI. I'd really like to get to 300-325WHP with this truck which brings up 2 main questions. Will E85 give me any notable power gain considering I'm going N/A (for now) and I'm not bumping up compression? Also, even without E85 I've read that I may be getting close to overworking/maxing out my factory injectors at this power level.
Basically to sum all of this up, the BTR TN cam, headers, and CAI/TB may not make quite the 300-325WHP I am after. I was hoping that if I should consider getting bigger injectors and fuel pump anyway, that maybe I could also kill two birds with one stone and squeeze some extra ponies out of the ol 4.8 with some E85 (maybe 3 birds with one stone since if I slap it all together at the same time I'll only have to tune it once).
Please let me know your thoughts and any recommendations for injector sizes as well. Not sure if too large of an injector would cause any difficulties while tuning.
Basically to sum all of this up, the BTR TN cam, headers, and CAI/TB may not make quite the 300-325WHP I am after. I was hoping that if I should consider getting bigger injectors and fuel pump anyway, that maybe I could also kill two birds with one stone and squeeze some extra ponies out of the ol 4.8 with some E85 (maybe 3 birds with one stone since if I slap it all together at the same time I'll only have to tune it once).
Please let me know your thoughts and any recommendations for injector sizes as well. Not sure if too large of an injector would cause any difficulties while tuning.
Without a serious compression bump or a power adder, e85 is not worth doing. You can tune very large injectors if (and only if) they are good quality AND have good data for all the tables (not just flow rate) that the pcm uses. A larger throttle body won't do anything meaningful on a cam only 4.8 either, except be an extra variable to tune for.
