Lt1 ss convertible trying to reach 750hp
 

Hello all:

I have purchased the huron twin turbo kit for my 2020 camaro ss convertible. The plan is to try and get everything over time to do a sub 800hp build
This includes:
Turbos bought from huron used 1 season on discount. (Makes whole build cheaper than most boosted builds)7k
Fueling + aux fuel line + flex fuel ( only if drop in pistons can be done at home)2.4k max
Piston/rods (if not lower power goals to sub 700). 2k

My search has led me to realize that there are quite a few questions I have that may be easier to ask here from more experienced members than finding out the hard way.

FUELING*****

Does the high side fuel pump need to be switched to lt4 as well? I have seen packages without this like wildhammers stage 1 kit, both of their kits infer that they can achieve 750hp supply

What are the power limits without this high pump?

Any body got a used high fuel pump?

Why buy a voltage booster for the pump vs just getting aux fuel package?

Can the aux package supplement enough with the stage one kit up to 750hp? (Without high pump)

Do convertibles have a different setup where I need this (says to 18' but i want to be sure that i do not need it)?:

https://wildhammermotorsports.com/16...eneral-motors/

How about injectors? For this level no one seems to stray from lt4 stock for the cost ratio.

PISTON ROD COMBO*****

Chances that these are true drop in? Meaning I can do this without balancing in a shop?

Are the gpi drop in combo piston rod pins Arp 2000?

L19 pins are hardened and more prone to catastrophic failure under high psi and the 2ks are the best. Thoughts?

Product in question:
https://gwatneyperformance.com/produ...QaAgViEALw_wcB

Any other true drop in combos that would suit my needs?

After the drop ins and upgraded cam, what would limit me to be under 800hp? Just the rear axle?

Also longevity, I want this boosted but safely, that's why I am thinking internals, if not, 650hp max. What longevity issues might the car face with my current plan?

Thanks for any/all replies.

Well… honestly you should spend an hour or two reading through this Forced Induction Discussion Forum. Most of these questions have been covered pretty well.

The GPI drop ins have a great track record. Go with the lowered compression version if you want to run 93 octane on occasion but you should definitely run some E if possible.

Think about your end goals. If you’re going to stay in the 700 WHP range or less then the LT4 fueling setup will work for you. If you even remotely think you’ll want more power, then get the TooHighPSI port injection setup now and get it over with.

I am thinking port injection, but what would I need other than the plates? Seems like the fueling with an aux line can handle 900hp applications... for 2.5k

We built my wife’s convertible to low 700s on a stock bottom end with an Magnuson 2300 and one of our cams That was as hard as we wanted to push the SBE. We built that car in 2016 and it is still running strong.

Build Thread


https://www.camaro6.com/forums/showt...ey+convertible

Hey OP... listen to Josh (Joshinator99) or KingLT1... both will guide you to the best outcome. (Several other forum members here will provide great advise too) Most of us have been there and it is a long deep rabbit hole when you start, so be honest with your end goals as it will save you a lot of headache down the road. Your fueling budget is kinda low if you are going with full LT4 fueling with E but will work with your current HP goals. Like Josh stated, TooHighPSI or similar is better set up (Port Injection) if you are reaching for the stars (over 750ish). Check them out or give them a call, as they are a forum member as well. Good luck in your build :thumbup:

Well the box of whoop ass on smgspeed is sitting at that range, for all lt4 upgrades... I am going with the flex and wide band regardless, so I suppose I am wondering what the lt4 fuel pump, lt4 in tank pump, auxiliary line, flex fuel, wide band, and lt4 injectors would allow for...

Like Josh stated earlier "If you’re going to stay in the 700 WHP range or less then the LT4 fueling setup will work for you."... probably can push to ~750 range, but after that you will run out of fueling thus the suggestion for port injection.
Check the pricing on LT4 HPFP lately? Prices are crazy at the moment.

Exactly, and everyone is going after those used pumps

I agree with Josh...this has been covered extensively in the past. A quick google would provide plenty of good reading material.

Common setup used on Gen 5 LT Engines in the past for FI: 38% lobe Cam, LT4 high side, DSX Aux pump, will allow you to get to roughly 760whp on E50-60 @ 12-13psi. I would do rods and pistons if tearing into the engine for a cam swap and dod delete.

If you don't want to tear into the engine yet, then go port injection, because the LT4 fuel doesn't go very far on E with the stock LT1 cam. The PI gives you a ton of room to grow.

I have XDI +30 injectors, LPE HPFP, and JMS low side in order to support 680-700whp on E60 with stock cam. A 38% lobe cam and low side upgrade would increase fuel system headroom another 150whp or so on the same amount of Ethanol.

That being said I would probably do port injection regardless at the current price of DI fuel components. I bought my XDI and LPE stuff when it was 45% less than the current prices. DI is easier to tune, but the PI stuff has come a long way. There are a couple members here currently working with PI on their cars and actively sharing information.

Start reading and good luck!

So youre saying with port injection I would not need the HPFP?
I see TooHighPSI I would need:
Vindicator 2 LT1/LT4 "SC" Port Plate System (for all LT1/LT4)
BOSCH Extended 800cc/min (78lb/hr) SQUARE PLUG Fuel Injector for "SC" port plates (Set of 8)
Looks like I would need the Reflex + controller?

Seems like I would still need the hpfp, correct?

No, you would not need to do new HPFP if you add port injection. The existing HPFP and DI injectors stay as is and you add 8 more port injectors.

Oh rad , so no need for the lp either?
I'm going port then, close in cost and easier labor imo since the convertible lower pump is a pain..

You need a solid low pressure pump setup to feed the fuel no matter which way you go (LT4 or bigger DI, or port injection). Think of the low side as the foundation that supports whatever option you run at the engine.

JMS voltage booster will cover you up to maybe 750 WHP or so (Paging @KingLT1 for HP fueling limits lol) meanwhile the aux fuel pump will do more. I’m a fan of the Fore Triple in tank pump setup…just throw down and be done with it. :nod: