Hey guys- not sure which direction to go was hoping to get a 60-130 in the 6s on pump gas- which direction would be best? Anyone have any shop built kits with a proven 60-130 with just bolt on turbo kit or 2650? Coming from a c7z just feel like this c8 is lacking .

 

I agree and waiting to see the info.
I love my c8 and it gets out from a dig great but 60-130 in my procharged c7 is in mid 6’s( manual also)and I won’t even run anybody from a roll in my c8. Lol
Id love about another 150rwhp in this thing but prices are stupid.
Even a solid 100 rwhp would be great,may be settling with some bolt ons and E85?

 

Prices are ridiculous. I did the limited amount of bolt-ons and there is no SOP feeling. I won't roll race either, unless I know who and what I'm against. lol
Once it hits 4th gear, you lose!!!

 

I appreciate your honesty on the bolt ons not doing much.
I have to keep reminding myself not to **** with this c8.
But it’s hard……lol

 

I know the feeling I did a procharged c8 for a customer, had it dyno tuned and the best i got in it was 8.6 60-130 and that was from a dig to 140. My c7 the has same head unit and build is 6.9.

 

I abandoned my C8 project for now for this exact reason. The cost wasnt a problem exactly. It was the fact that even for 40k the 60-130 would be terrible.

 

I actually wish I left it alone. Halltech, ARH headers, ported tb and intake manifold. 17rwhp/17rwtq. Not impressed.

 

First time in some time to have folks step up and discuss this without it degrading into a sales pitch, smoke and mirrors, seat of the pants statements, or brand loyalty.

So, 'll take a chance and ask a dumb question given the level of honesty so far. Since adding raw horsepower, even at some pretty lofty levels (200+ rwhp), doesn't seem like it's going to do the trick for 60-130, I've read folks pointing to lack of transmission programming and the gearing in 4th and beyond as the sticking points. What is it technologically that makes this the impasse? I know nothing of these DCT transmissions other than driving my own, but what makes it not feasible to change the actual internal parts to change ratios or rear end gears to accomplish the same? Clearly this can't be done easily or some tuner/shop/supplier would've done it already, but it just strikes me as odd that there's not more discussion about it. Is it just too expensive to go down the road of the transmission internals?

 

The way I understand it TCM control will help to a degree. It still doesn’t solve the gearing though. This car has multiple systems talking to each other so simply swapping the gears isn’t an option. The TCM control can maybe solve this as well. I stopped caring so correct me if I’m wrong. That’s basically it in a nut shell.

The car checks all the boxes for most people and is well built for their use case scenarios. Us power and speed junkies just have to be patient or move on for now.

 

Not sure about any headers but every little bit counts at a cost. I went from 11.29 down to 10.95 with Halltech Intake, ported throttle body and ported intake manifold. The power is there.....I just put a tire on the car in order to get a better 60ft time. The majority of the power is actually at near bottom end but not much more at the top. The car definitely needs a tune with those bolt-ons. An E85 tune would be enormous but the cost is ridiculous
I have over 30 drag strip runs with my C8. And there is no question that the Halltech Intake made the most power with my combo when I replaced it with the Attack Blue filter. However, it is not enough horsepower to feel the SOTP. lol. You'll need a supercharger for that.

 

Look at the factory HP curve and it is pretty much done after 5500 rpm. It climbs a bit towards the peak, but the slope is really down. With tuning now available, a cam swap will go a long way in fixing the top end. Not enough to go from 8s to 6s, but heads & cam with e85 shows promise. Unfortunately, the C8 is expensive to work on.

 

A non z51 car with the stock tire 130 mph@6900rpm Gear and Shift Point Calculator | GTSparkplugs Now where was those heads and cam posts. LOL

 

Here are some of my observations on this matter, and full disclosure I am the tuner for Cicio Performance and while we work on these cars I have a pretty unbiased opinion on the performance of these cars and I am not here to sell you anything lol. Power for power there is no getting around the fact that they are slower than the other DCT platforms we work on even though they are the lightest. The engines make power pretty easily and the stock LT2 engine seems to be pretty strong, so that isn't really part of the issue seemingly. The gearsets also seem to be very strong, but a lot of the issues for the lack of performance in my opinion are trans related one way or another. First off the gearing is pretty poor especially after 3rd gear, so the gear splits get really long, especially on the 4-5 shift. Shifting at 6500 rpms and then dropping down to 4800 or below really kills acceleration once you start making more top end power with a centrifugal SC, turbo setup, or cammed N/A setup. Even though you can raise the rev limiter in the ECM the TCM still limits us to 6600 rpms for the time being as well, so you can't take advantage of more revs to help overcome some of the gearing/power under the curve issues. Another issue we fight on these cars is the clutch crossover on shifts. Most DCT cars will cross over to the other clutch basket and bring clutch pressure in fully right away. These cars bring the clutch pressure on a gear change in slowly, which I'm guessing is an attempt to keep things in one piece and feeling smooth from factory, but it makes it so the clutch slips a bit when trying to throw power at it, so you have to be a little soft with power delivery on shifts, which sort of negates the purpose of a quick shifting DCT. I am hopeful we will be able to solve some of these issues when TCM tuning becomes available, but I don't think it will be a magic "ah-ha" moment that will just make these cars so much faster. One other thing to note is that there seems to be some pretty extreme inconsistencies in clutch and trans performance, whether the car has a factory clutch or aftermarket. It just seems like you can build five of the same car and they will all hold a different level of power between shifts, or at least one or two of them will be lacking compared to the others. Not sure if this lies within the valve bodies, clutch cores, or what exactly but it is just a level of inconsistency we have never experienced on other platforms.

Working with the hands we are dealt mentioned above this is my opinion and observations of what can be expected on some of the various setups. Stock they seem to 60-130 in the mid 10 second range at ~440-450whp. With a Procharger kit at around 600whp we have seen mid to low 8 second 60-130's. With a TT kit on stock fuel system you can expect mid to higher 600's (700ish if you really want to ride the edge of the fuel system) and it will go mid to lower 7's 60-130 (I've been high 6's but again that was on the edge of the fuel system and I don't let cars leave out in the wild being that close to out of fuel), on a stock engine with port injection and ethanol you can pretty safely (again, my opinion and observation based on what we've seen) make 850-900whp, which on these cars seems to be good for higher 5's 60-130. At that level they are about as quick as a stock engine GT-R that makes a peaky 800whp/650wtq to keep the rods in the engine, but weigh in at nearly 4,000 lbs. Since we are on a Vette forum we can compare my bolt on C6 ZR1 that makes 750whp and does sub 5.5 60-130's with a gear shift, so power for power it takes the C8 a good bit more as you can see.

My overall opinion on the cars is that they are pretty awesome to drive with some boost, and they make all the right noises and give the extra power they were lacking in factory form. However they are for sure not the fastest things out there nor are they super cost effective to modify. However with how many shops are working on these cars we are all for sure chipping away at development and hopefully in time they can become a force to be reckoned with!

 

Kudos to 1SLO2OH for the extensive, factually supported, and humble answer.

 

Thanks for the replies- Boost districts e ray twin turbo kit allegedly went 4.8 60-130 and in the 9s,
need to see more info on this car.

 

@1SLO2OH this is the best answer. Shop transparency is a great thing need more of it from the guys that work on these cars day in and day out. Thanks for taking the time to share.

As far as guys complaining about these not being cost effective I completely agree but I've never found an objective way to debate that effectively. Reason being you can get an F-Body or C5 or whatever platform cheap then make it fast. Even comparing to C6/7 or new GT500/ZL1 etc they're very different cars than a C8.

If I had a C8 Stingray or E-Ray I'd do the bolt-ons and flex fuel tune route then leave it alone until TCM tuning becomes available and there's more consistency found with the DCTs. It's not surprising hearing about the inconsistency given folks with stock cars either get a good one or one that needs a new valve body, new trans or other DCT related issues.

 

Cost is likely the biggest factor.
A bespoke DCT gearset could run $20K or even more installed, that's not small money.
Some here have said they would spend that in a minute but for what benefit?
It's unknown so who is going to be the first to find out?
From what I am seeing, even the Dodson DCT upgrades for the GTR are for strengthening purposes only, they run the standard ratios, not revised.

 

For your entertainment

 

Insane! is that a Lambo TT?

 

Yup!
best run to date are 60 130 2.6 100 150 2.2