2650 max hp & lb's on 93 and tuning questions
 

hey guys,
im wondering if anyone has a zl1 or SS with similar build, i just want an opinion on if my tuner is kind of putting a baby tune. i have a 2018 2SS A8.

Current Mod List:
2650 edelbrock 2650 (non ported)
ported and milled stock heads (gpi)
forged wiseco pistons & k1 forged rods(lowered compression)
1-7/8 catless LT headers going to 3" mid pipe to stock NPP
flex fuel sensor (which is pointless now)
zl1 intank low side, zl1 HPFP, zl1 injectors, and DSX aux pump
custom spec cam motion cam with 34 or 36% fuel lobe, I cant remember.
103mm TB
4" rotofab CAI (have the big gulp on order due to it dropping a lb of boost in the big end)
MSD plug wire (not sure what spark plugs they used)
DOD delete
BTR .660 platinum springs w/ Trunnion kit
GM performance CTSV lifters
BTR pushrods
Smith brothers bronze bushing rocker trunnion kit
a bunch of seals and gaskets
BTR lifter trays
ATI Harmonic Dampers
9.1" lower & 3.5 upper
Circle D converter 2800-3000 stall

Im sure im missing a couple things, but the main issue im running into is the CAI. It starts out on the dyno running 12lb of boost then drops off a lb at the end of the pull. my tuner suggest its bc of the smaller CAI. its making a little upward of 700whp on 93 pump gas. My tuner is saying that he really doesn't want to go anymore due to the fact I'm not running any meth or port injection. I've seen multiple people claiming to be making 850whp on pump gas my question is why they can but i cant lol. The shop that I am using has tuned it before with FBO and I've had no problem. they're deff a reputable shop, and they know their shit. am just wondering if anybody is running more than 12lb of boost just on pump gas without anything else, and or if someone is breaking over 800whp on pump gas. 800-850 is my goal, i do not want to go much that because i drive the car during the weekends. I don't want a straight race car to where every time i drive it something breaks. i want to enjoy the car. end of the story my tuner said i have to be really careful on just pump gas, but i dont see why 800whp isn't achievable on pump gas.. whats the max whp people are making just on 93 with zl1 fuel system with an aux pump, and how many pounds of boost?

I don't think anybody on here has made 800 on pump 93 without any meth help using the Lt4 system. Even on E85 the Lt4 system taps out pretty quick. To get to the 800 you want you'll probably want to move to the Big Bore hpfp and some +30 fuel injectors. As far as making it a race car you're already there with all the work you've done so far. From 800 up your approaching the level where the 8spd becomes iffy and can let go whenever it feels like it.

Thanks for the reply, im basically just wondering if little over 700 whp is a good number for pump gas. Im going to go ahead and order the big gulp because its dropping 1lb of boost on the big end. he told me that i need it because its restricting it. They claim the big gulp will pick up anywhere from 20-30 whp and i wont be dropping boost.. i mean 1lb is not that much, so should i even waste the money on a big gulp? i said i didnt want meth but now curious as to what it would make with a alky kit and how much more i could run the boost up.

LT4's have made right around 800whp on 93 octane with heads/cam/ported supercharger. Andrew @ CSP did a couple years ago. That being said since you lowered the compression I would think you could run 15psi on 93 octane and be ok. You are not really much different then a LT4 at this point with the lower compression forged pistons. Your dynamic compression is much lower as well with the cam.

In this case you can likely make as more power on 93 compared to E85 because you have greatly reduced dynamic compression which raises the octane wall. E85 would make more power all else equal but you will run out of fuel system on your current setup before you get to that point.

This annoying reality keeps circling back on me :bonk:

i dont have a ported supercharger but id think i could make 800, but my tuner keeps on saying there is no way.. idk if its because he wants to be safe or what. his last txt to me said made 12 psi but you have to remember that at the end of the day , have to be careful on pump gas....................
i get it he doesn't want to push the limits, but is it really that risky to push more boost and make that kind of power on pump?
he said there is no room for E content.

Maybe your intake pump is on the weak side. There have been cases of not all pumps being created equal. I would absolutely stay away from meth. There are too many things that can go wrong with those meth setups. I would go ahead and do the big gulp and just maximize what you got now.

You don't need a ported supercharger. I was referencing a LT4 which has a much smaller supercharger then you. If you were still 11.5:1 compression then yea what tuner says makes sense. Lowering compression will allow 93 octane to go a lot further. Without looking at the tune and logs we can only speculate. How rich of AFR the tuner is targeting will make a huge impact on available fuel system headroom.

Exactly. OP: post a datalog of your dyno run and tune so we can see them. We’re guessing otherwise.

I’m making 837 WHP on 93 only at 14.7 psi boost, so it’s very doable with the lower compression (I do have a bigger fuel system though). You don’t need meth to hit 800 WHP though, I did it with plain LT4 fueling and a JMS voltage booster previously. Going to E50 brought me to 927 WHP so it just goes to show how much power E is worth if you have the fuel system to support it.

It's encouraging to see your 100 hp gain on E, because that's where I'm headed shortly except with FIC injectors and LPE's Big Boy pump. Any other fueling mods that aren't in your sig?

Don't know the comparison between the Edelbrock and Magnuson 2650s, but my car SBE is making 930 on 93 /w meth and another with a built bottom end is making 960 on 93 /w meth. Stock lt4 fueling, dsx lowside, cam, heads, fbo

You must be spraying a ton of meth. In one of your previous posts you said you were at 700 and your fuel was maxed out at that point.

Nope. Fore triple in tank, to LPE BB HPFP, to LPE +52% injectors. Pretty simple for the most part. No meth or port, just tune one ECU. If you need to just get 93 octane, it's no problem and if I have access to E the car automatically adds the extra timing in (and the extra 90 HP too...). :happy0180:

I wouldn't say its spraying a ton of meth. The car makes power to redline so the cam aiding the high side that was limited(lowside was good) and allowing me to raise to redline from 6500 to 7200 really lets that HP bloom. The ported heads, meth, and pulley do help a lot too. I'm also at low elevation.