Quote:
Originally Posted by CC BOY
Thanks man! I definitely need to re-check my lifters. If my mod shop can’t measure lifter length, I might have to go your route…
I also wanted to ask about the fuel system. My tuner told me that without cutting pistons, it would be pushing the limits, and he recommended upgrading and optimizing my fuel system (injectors, ignition coils, and fuel rail). Do I really need to upgrade? I recall the stock L99 injectors are 42 lb/hr. Based on my target of 480–490 hp and the requirements for E85, that’s already very close to their limit. So if upgrading is really necessary, are there any recommended brands or part numbers? It’s been tough finding reliable info around here.
Also, my use case is track-focused, especially stop-and-go style circuits. I don’t run endurance races, but I do frequently hit high RPM. With zero tolerance for knock, is it still possible to reach my target power?
I looked into the 4500-stall torque converter you mentioned earlier, but I found a potential issue: paired with a BTR stage 4 camshaft, it seems like it won’t lock in 1st or 2nd gear because temps would spike too quickly? Not being able to lock 2nd on track might be pretty annoying… Would a 4300-stall converter be better? At least on a ~1:50 per lap circuit, I could use locked 2nd occasionally. I already have an independent oil cooler, transmission cooler, and an oversized aluminum radiator. Any suggestions? Thanks!
|
On your stall converter I have my tune for the trans to lock up anytime I am in manual mode in whatever gear I am in, and in sport mode it doesn't lock until 6th gear at 55 mph. I would call Chris @ Circle D and ask him what he suggests, he helped me with mine. Your converter operation would be all in how it's tuned. I don't race, so I couldn't answer all that about it. As far as your fuel system, I'm at 486rwhp,475rwtq and am running stock injectors just fine with a ZL1 fuel pump, no issues, still have plenty of injector left, but if you are going to run E85, you will need to upgrade your pump and injectors to handle the different characteristics of E85, and a flex fuel kit. I don't run E85 as all I have read about in on here, and other performance websites says there isn't much to be gained from it unless you are boosted, then there are really good gains to be had. On your coils and fuel rails, you will be fine with the stock items. And as you mentioning being at the limits on having to flycut your pistons, with some stage 4 cams with very high lifts, you would need to do that and fly cut the valve reliefs deeper that are already in the L99 pistons so the valves don't accidentally "kiss" the pistons when you do any high rpm's. As far as compression goes, that wouldn't have to be done, our L99's are at 10.5, and the LS3's are at 10.7. So you see that is why your pushrod length is curcial for engine/valve train safety. If any of this is incorrect, someone will surely chime in, or they will add to what I wrote. And as acutron said, contact Andrew at GPI, and he can get you going in the correct direction.