In the C8 performance section I started the thread topic regarding 15% ethanol. I had done some research and pretty much decided bolt ons with no tune were waste of money and time besides often cancelling your warranty if you still have one. A five HP gain at the crank is generally considered to be felt in your head by justification but not in your backside. The general consensus of members that had tried it was that you could run up to 30% ethanol on the stock tune and it would be able to remain within acceptable control without setting a check engine light. I have no intentions of running that high a percentage and have not seen any dyno or quarter mile results as to how much improvement there is but have found what I feel is a small kick in my butt dyno by running 91 octane no ethanol and adding 3 gallons of E85. This gets you to about 95 octane and 15% ethanol which allows the computers to take advantage of available control parameters. It seems to wake the motor up a bit at the expense of reduced gas mileage. If you have zero corn juice 91 or 93 octane premium and E85 available give it a try and see what you think. This is by far easier to try than any bolt on and may give as much or more power than the bolt ons but sure will not sound as cool as a new exhaust system. Obviously going to a flex fuel tune to allow use of full E85 at 105 octane could yield considerably more horsepower but the return on investment is low similar to bolt ons and the warranty loss again comes into play...
Give it a try and see what your feelings are. All it will cost you is a bit of time and way less $$$.

BTW, Paragon Performance has stated in at least one of their videos that GM has not left much horsepower on the table in the LT2 without multiple mods and ECM tuning. They did reach 500 RWHP on a C8 with quite a few bolt ons and E85 tuning.

 

500whp is decent, but at what cost? You could do a $4500 flex fuel setup and be at 465whp OR spend an additional $10,000 on bolt-ons to get to 500whp. Terrible value for money.

 

yep

 

@combatninja
^^^^^^
I agree 100% with that assessment. Way too many dollars for the return. I suspect there was some help from the manufacturers and perhaps assistance from P P for experimental purposes to determine what might be the best options.
I even think the price of converting to flex fuel is too high but at least you do get to run cheaper gas as an offset. You would have to drive far more miles than most Corvettes go to make up the initial cost.

 

Why so much focus on on just dyno numbers? People should be able to make their own choices when it comes to modding their cars. It could be a bad or good choice for some. I do all of my performance mods a the drag strip. When I go to track I meet fellow C8 owners. They are there to get the best times out of their C8s. Most of C8s are stock. But then you have this one c8 that stands out from the others. Most of us are running 11.30s and slower. Then you have this particular c8 running 11.00s with all seasons michelins. I eventually approached the person just to ask him what have he done to his car. There was an hesitation then he later disclosed his bolt-ons.....no headers. Anyway I duplicated his bolt-ons and was able to run the same numbers on all seasons michelins. Bolt-ons work period. So if you think that's nothing, then I urge you to keep your car stock. $1300 for few bolt-ons and almost 4 tenths, 😆

 

Not everybody is into the 1/4 mile. Some of us just want a car that can hold its own at highway speeds. I don't care if you throw $20,000 at bolt-ons, your C8 is going to get positively walked by a new Mustang from a roll. Facts. The quarter mile is basically a launch thru 3 decent gears and then you're hoping for the best in 4th. If you have a Z51, you will need to shift to 5th and you can just feel the car losing tenths. I'm not hating on it but newcomers need to understand the limitations of the platform before they sink $10,000 into the car and it still has a 60-130 time in the 8s.

 

Glad to see some c8 owners are on the same page.
I love my c8 don’t get me wrong……but I’m not throwing 20k at it to get 7’s at 60-130!!!
My procharged c7 runs mid 6’s 60-130 …….I bought good used items off other people on this forum and don’t have 5k in it to get those numbers.
And the cars a manual.
All stock internals. Reliable as hell. Just can’t part with it cuz I won’t come close to something comparable at the price point people can buy them at.

 

If you want to fly up the public road with those mustangs help yourself. Because that's what it sounds like. A stock C8 is not a topend car. Plenty of anything can outrun a C8. So what is your point? If you're going to run 60 to 130mph on the track then you need a supercharger or turbo. Do you even have a C8 sir? If so, it appears you're not happy with it.

 

Yeah. I've had 3. I'm fine with them but you have to be realistic about what you expect from the car. I don't understand sitting in some stinky paddock all day just to get 3 runs down a drag strip any more than you apparently understand me wanting my car to be 'whoa' fast from a highway roll. To each their own.

And by the way, C8s still suck in the 60-130 with blowers or turbos. I've driven both. The gearing is abysmal. Yeah GM, I need 5 overdrive gears and a theoretical top speed of 300+ mph.

 

Understood

 

So … I understand the gearing sux. Both the Stingray and the Z06.
im not sure why you bash the guys that mod the Stingrays when posting up small (cheap) mods … and when TOGETHER make a base Stingray into a 10.9-10.7 1/4 mile car for less than $2k.
F .. for sure the Corvette tax is going like Lambo these days. However, a little mix of E … a little bit of bolt ons (without w tune) are going to have Stingrays in the mid to low 10’s.
I was working on doing so until I got my Z06. 9.7 is my goal. It will happen.

 

I'm not bashing anyone. There is a world of difference between someone tweaking a car chasing tenths and someone who wants their car to be 'faster' when measured by their butt dyno. I'm just trying to be the voice of reason and let some of these newbies (like the OP here for example) that they need to manage expectations and be realistic about what they are trying to achieve. Nobody that bags on the C8 for being slow is talking about gears 1-3. It is 4th and up that are such a bitter disappointment. It's almost like it is two different cars.

 

Maybe one day there will be an opportunity to be able to change out the upper trans gears. The sooner the better

 

That's what I've been hoping but I don't think it is likely. We're basically 6 model years in and the TCU has not even been cracked. I'm not even sure if anyone is actively working on it. The ability for these cars to rev higher would give a lot of awesome options for NA builds. You'd probably see 650hp NA cars if they could just let them rev. On ethanol, you might see 675. That alone would be great but the real game changer would be physical changes to gears. All we need is a simple 1:1 4th gear and then the old 0.88 4th could be the new 5th and so on. We're talking one cog change and the ability to tune it. You'd see NA C8s in the 9s.

 

It really is 2 different cars.. GM gave us great 1-3 gears for launch and then used 4-8 to solve their CAFE requirements. Personally, I'd take paying a gas guzzler tax and have better 4 and 5 gears. Or GM could have offered better gas mileage in their other cars/truck so the C8 didn't have to take the hit in gearing. It's all about corporate CAFE averages.

 

I don't buy that CAFE is the reason they had to completely **** up the gearing in 4th thru 6th. These are 3500+ pound cars with 5.17 effective final drive in Z51 form, which is easily 50% of the cars sold. They have gnarly aggressive gearing in 1st and 2nd, almost ridiculous. I don't buy it. They so far have used one gearset for the whole range and all they do is trade out the transfer gear to get the final drive of their choice. Jury's out on the ZR1 but I'll bet it has....the same gearset. It was a cost-cutting measure, not a CAFE workaround.

 

It's not cost cutting on the original C8 design for gearing. It costs no different to design one gear set over another when starting from scratch. I'll give you the using the same sets from Stingray to Z06, etc would be considered cost cutting/penny pinching. However, the original gear sets designed for the C8 were about meeting CAFE regulations and getting their MPG targets to avoid a gas guzzler while keeping performance on the Stingray. It's a balancing act.

 

Using one gearset across the whole model line absolutely simplifies and streamlines production and, therefore, saves money. Tremec is no longer building the gearboxes as far as I'm tracking. GM does it now.

 

My 2 cents 2024 base model
Cat Back X pipe exhaust----Blue lavanza air filter---Pedal commander
Calif car running our crap 91 oct fuel
Just for fun I took it to the drags in Lodi to see how it would do
I was 96* out that day
Very disappointing Best run in the morning was an 11.58---rest of the day was in the 11.60's
I was told if I ran str8 93 Oct fuel it would run as advertised 11.20's 0r maybe 11 flat with my simple
mods----- will try that this year
Was told that with 93 oct the ECM will add anywhere from 4-6* of timing in the mid range/top end
to me it was lazy from 2-3 and 3-4 shifts and never got into 5th Maybe the 93 will give me better response/TQ so I can go thru the lights in 5th
Not interested in a $5000 tuning bill ---may decide on a Solar 102 T Body--- a better intake manifold and finally a set of headers with cats---
PS one question When you guys drag race do you use the Launch control ? To me it bogs a lot off the line OR should I just turn OFF the T/C and floor it ? THKS

 

So "not interested" in a $5000 tune/flexfuel setup but you somehow are interested in $5000+ in bolt-on junk that will deliver LESS power over a narrower range than the flexfuel? Makes sense.