[Joelskidelahoya]

I am looking to do my first round of upgrades. I have searched the forum and have not found the exact answer. I have a 2021 1le m6 all stock at this point. I want to get the most bang for my buck.

I am interested in switching to e85 primarily. It seems that this in itself is not worth it. So I am considering doin several thinks with the e85.

I have been looking at rotofab, JLT and cold air inductions CAI and pairing one of those with an lt5 throttle body. is the JLT superior?

Last tangent is the secondary cat deletes. I’m leaning towards holding off on the headers due to the post about how secondary cat deletes yield similar power gains. Does anyone have concrete proof of gains from secondary cat deletes. I like the stock exhaust and do not wanna spend 2 to 3k on an exhaust system. I enjoy the stock npp exhaust. I just want to get best power gains for the cost since I do not plan to cam for years

[RideWithDanger]

Rotofab is typically considered the best, but JLT has a new intake coming out in August if you can wait. Supposedly it's supposed to be the best flowing intake on the market.

The secondary cats are worth like MAYBE 5 horsepower, so on their own pretty pointless but with E85, CAI, TB, and a tune it doesn't hurt, but it's more for the sound than anything. Headers can yield a bit more but again, typically done for the sound over anything because bang for your buck it's just not that great.

I would suggest going FBO or at least all the mods you want at the same time, that's what I did. You won't have to have the car down for more time, or pay for retunes. Can also cut down on labor charges as well.

[m6-lt1]

E85 is the best bang for the buck mod you can get on these cars. I think you possibly misinterpreted what you read since you said e85 by itself isn’t worth it. I think what you may have read was that it doesn’t make sense to only do one mod that requires a tune. If you’re gonna do additional mods that require a tube, it makes the most sense to do them all at once. If you only can do one mod though e85+tune is easily the best bang for the buck mod on LT1 powered cars.

Deleting the secondary cars aren’t going to gain you anything. I think you again misread something. Deleting the PRIMARY cats nets you a very similar gain to doing long tube headers. Headers still gain more but not that much more versus the cost of headers versus cat deletes.

[Joelskidelahoya]

Got it thanks.

I’m leaning towards jlt or roto fab CAI, lt2 intake, lt5 TB , cat deletes and e85. I honestly like the way it sounds n the NPP.. I could do it myself n take to get tune. My tuner is a good ways away so I wouldn’t wanna drive untuned headers to em and the labor on headers ain’t cheap. From what I have seen headers don’t really seem worth it till u go cam.

I might hold out for the JLT intake. If it’s supposed to be the best performing one.

[RideWithDanger]

Originally Posted by Joelskidelahoya

Got it thanks.

I’m leaning towards jlt or roto fab CAI, lt2 intake, lt5 TB , cat deletes and e85. I honestly like the way it sounds n the NPP.. I could do it myself n take to get tune. My tuner is a good ways away so I wouldn’t wanna drive untuned headers to em and the labor on headers ain’t cheap. From what I have seen headers don’t really seem worth it till u go cam.

I might hold out for the JLT intake. If it’s supposed to be the best performing one.

Similar to what I did. Rotofab, LT2, LT5 TB, but I did headers and a full catback instead of E85. I went with rotofab because I am impatient lol. In all honesty though, unless you plan on doing something like the MSD and 103mm TB, the rotofab is plenty. There is no shortage of air with the rotofab at all, even the stock intake is surprisingly good. It also may be a while before JLT can really be compared to a rotofab if you are looking for true results.

Don't get forget about remote tunes as well. Or at the very least, install the the LT5 TB at your tuners place, since that and running E85 are the only mods that really require a tune.

[Joshinator99]

If you’re getting headers you may want your tuner to do a “preemptive strike” on the tune. I don’t want to say too much on an open forum, but suffice to say certain tune tweaks should be done before you do headers, and then the fine tuning can be done after. If you live in a stringent emissions state, you’ll want to follow my advice.

[Megahurtz]

Green drop in filter, ported TB and Flex fuel on E60 is your best bang for your buck. Don't bother with cat deletes unless you're going to get headers.

You don't need a rotofab or JLT intake unless you add more boost and especially if you don't have headers.

[Joelskidelahoya]

Do you have results for flex fuel only n port TB set up? I’d just like to do something to give it a lil more power. Long term plan is to cam it but that’s down the road so not in a rush for headers.

Originally Posted by Megahurtz

Green drop in filter, ported TB and Flex fuel on E60 is your best bang for your buck. Don't bother with cat deletes unless you're going to get headers.

You don't need a rotofab or JLT intake unless you add more boost and especially if you don't have headers.

[s346k]

1 e85. worth every penny when paired with other mods. typically good for 20-25 whp over 93 octane.

2 air intake system. it is my experience that any of the air intakes still utilizing the narrow factory bridge between the engine bay and front of the radiator will all suffer the same fate. ultimately being choked at the same place. this is the weird looking connection on the face of the rotofab air box. it's the same size as stock because it has to join a factory piece of the air intake system. removing the front of the stock air box will flow more than enough air for a mild bolt on car, and its free. LT2 manifold is 100% legit and worth it. 95 mm tb is not worth the hassle imho. the stock one flows plenty for mild bolt ons.

3 secondary cats. leave them alone. at best they make the car .2 db louder and offer 0 performance gain. as mentioned, removing the primary cats is the only way to get power from the stock exhaust system.

in conclusion, given your bang for the buck emphasis, my suggestion is as follows:

LT2 intake manifold
modified stock air box
flex fuel

spend the time & money on a quality tune. paramount.

[s346k]

i should add

i wouldn't do any of these mods without a tune. i know for a fact that cutting the factory air box will upset the maf enough to lose a lot of performance (trapped 7 mph lower in the 1/4 mi). the LT2 intake needs pulled farther (higher rev limiter) to get the most out of it.

[Joelskidelahoya]

Appreciate it s346k. 1st time I’ve heard bout that as an option. (Stock air box mod). It seems e85 n more airflow is the best bang for your buck. 1k to 1500k vs 3 to 4K FBO. All for a few 20 ish horsepower. Wouldn’t a better throttle body make it more snapping more so than dyno hp. I had bad luck with a ported TB on my gen 2 CTSV.

[GreyGhost702]

Originally Posted by Joelskidelahoya

Appreciate it s346k. 1st time I’ve heard bout that as an option. (Stock air box mod). It seems e85 n more airflow is the best bang for your buck. 1k to 1500k vs 3 to 4K FBO. All for a few 20 ish horsepower. Wouldn’t a better throttle body make it more snapping more so than dyno hp. I had bad luck with a ported TB on my gen 2 CTSV.

Ported TB’s have always been a pain in every tuners neck. Few are worth doing in terms of $/hp, but the throttle response is usually a nice seat of the pants upgrade. I have said before, the LT2 IM + LT5 95mm TB w/adapter has got to be the best budget upgrades you can get and damn sexy on top of it all. You can get the whole slew for less than $500. The next best in aftermarket will cost you over $2k for a IM+TB combo. The $/hp comparison isn’t even close, hands down the LT2 smashes the aftermarket alternatives. As far as hassle, yes there is some prep work and potentially some sacrifices to be made depending how you want to present the LT2. Prep kit from Phastek is only $45 and about 30m-1hr of your time. If you want to run the IM cover it’ll cost $120 more and there are some hood clearance issues to address. Minor inconvenience for a lot of sexy. The 95mm TB is going to feel good everywhere and snappy compared to stock, even though the IM is only feeding 87mm in port, the 95mm is going to utilize it better. The 87mm TB doesn’t use its full port because you lose area to the blade and rod, so the 95mm is actually more appropriate for a 87mm inlet than a 87mm TB is.

As far as Cold Air Intakes, they are just engine bay beautification until you get toward the end of heads/cam combos and start reaching for max effort. The OE intake and box will not show restriction til you really ramp up the air flow capacity of the engine and start spinning beyond 7,000. If you had a 90’s Camaro, a CAI was an upgrade, but since then factory equipment and filter media are leaps and bounds improved. Same for cats. The primary cats will support NA peak just fine, if you could adapt them for LT’s they would still probably perform just fine. I do recommend secondary cat delete if you are looking for a sound upgrade. It is subtle, but more pronounced with an aftermarket muffler. $/hp there is nothing to be had from it, even tuned. So it’s personal preference, just like mufflers, no $/hp there either.

Nice thing about LT2+LT5 upgrades, when you are ready for heads/cam you will already be set to take advantage of more flow and RPM.

[s346k]

when i had my car on the dyno i swapped the stock tb for a pray ported (LT1) tb. it gained .5 hp. car had the cut stock air box, full exhaust, pray ported LT1 intake manifold and (e85) tune.

here are a couple pics of my cut stock air box.

i added an msd manifold, LT5 tb and rotofab. the car picked up 14 whp peak and lost 0 tq. it gained 35 whp @ 6500 rpm. ultimately gained over 2 mph from only "14 hp".

what im saying is the car trapped 121 with next to nothing done to it (cut stock air box, exhaust, ported stock manifold & tune). the next 3-5 mph were at a steep cost.

[Joelskidelahoya]

Originally Posted by s346k

when i had my car on the dyno i swapped the stock tb for a pray ported (LT1) tb. it gained .5 hp. car had the cut stock air box, full exhaust, pray ported LT1 intake manifold and (e85) tune.

here are a couple pics of my cut stock air box.

i added an msd manifold, LT5 tb and rotofab. the car picked up 14 whp peak and lost 0 tq. it gained 35 whp @ 6500 rpm. ultimately gained over 2 mph from only "14 hp".

what im saying is the car trapped 121 with next to nothing done to it (cut stock air box, exhaust, ported stock manifold & tune). the next 3-5 mph were at a steep cost.

do you know performance numbers for ur 1st mod. hp and track times. for airbox n e85