SiloGM

Recently living in the country here in northeast ohio I was given the opportunity with some friends to do a top speed run in my 09 SS/TC and want to share my experiences.

01. "Track" and preparation

While cruising some old country roads my friends and I stumbled across a abandoned road in pretty good condition, consisting of a steep lefthand hill and a 1.6 mile straight the ends in a dead end.

The road was not pitted or did not have any potholes, it was straight as an arrow and in great condition.

Being the only house at the end of this road was demolished a few years ago there is no reason to come down this stretch, meaning nobody around that could get hurt during a bit of fun.

Wanting to test out my new tune in my SS and also a bit of top speed fun for the first time, my friends and I set up a track and spent a day or so making sure there was nothing on the road that could cause problems. This meant combing over the road in the daylight and making sure at any point I could fly off into the field on either side for a run off if I have a major problem.

We set up a big sign at the one mile mark to remind me to brake, giving me a 0.6 of a mile to slow down from whatever speed I was at.

02. Car and Car Prep
I recently bought my 09 SS/TC 4 months ago and love it, it came with some tint on the windows and the GMS1 tune and was bought from the only other owner. The interior of the car was reviled to NEVER had a passenger in the car and is as MINT as they come.

Since then I have added a boost gauge and AFR gauge to the pillar with my RPD so I can keep a eye on everything and a 24 psi trifecta tune and downpipe. My trifecta tune is toggled with the traction control button so I did this run with the GMS1 and trifecta.

My friends and I made sure the brembo brakes were all in good working order and washed and waxed the car to make it as slippery as possible. All the tires were at 33 psi. It was low humidity and 80 degrees Fahrenheit on a summer day.

03. First few runs. 130+ mph
After driving there and my friends setting up near the end of the straight to help if there were any issues and I began my first run, I decided to go down the hill at 60 in 3rd gear, trifecta on and go for it. 3rd topped out at 104 or so because I decided to shift at 6k, at this point the car was rock solid stable and not scary, not even exciting. After pulling to the top of 4th gear at about 120 I shifted into 5th and continued to a first run of 130 which was starting to get unnerving, before braking at my sign quite firm and stopping a good 1000ft before the end of our track.

On the RPD I was showing a 86 degree intake temp and my coolant was well over 203-205. We drove the car slow on a side road near the track to cool it down back to 180 degrees or so.

For the next run I decided to do the same thing but with the trifecta tune off and just running on the GMS1 tune. Surprisingly there was not much of a difference speed wise with me letting off at about the 130 mark, but I did brake a bit later giving me a few extra seconds of acceleration. The temps didn't even break the 200 degree barrier this time, which was notable.

Last Few runs 140+
For the last few runs it was decided I would go trifecta only and brake as late as I felt comfortable, also I was going to go as fast as I could through the curve onto the straight.
First I tried 80mph on the curve and gunning it through 3rd onto the straight. The car pulled well and the extra speed helped me get into 5th quicker, and passing the 130 mark quite easily. The issues started when I passed the 140 barrier.

At 140 the sunroof made a jarring pop sound and the air passing over the sunroof got WAY louder. I slowed down very firm, going hard on the brembos and proceeded to look at my car. The sunroof had actually popped up a little bit. Opening and then closing the Sunroof caused it to seat back on the tracks correct and close properly.

We decided to add a bit of masking tape over the front of the sunroof, would it do anything? Probably not but it was more for my own confidence.

For my final run after my car and brakes cooled down I decided to go bonkers and go through the curve with a ton of speed. Being a slight left hander it wasn't too hard to go through at 90mph. The pulls through 3rd and 4th were quick and once in 5th the speed started to rack up. at my highest speed of the day of 144 I heard a crack and slowed down harder than I wanted to and swerved the car slightly (remember smooth inputs people).

Something had kicked up and at 144 hit my tire well behind my front right tire, blowing a hole straight through it like a shotgun. The car was hot as **** at this point at about 207 degrees. We let it cool down and laid our sign down and went back to the shop.

Cobalt SS High speed impressions
The SS did feel quite quick when doing these runs and was a ton of fun to handle. At up to 100 mph there was really no issues with the car. I feel like anything above 120 was starting to get so loud and rattle ridden that my confidence to go faster was ruined, 140 and up was very unnerving, there was shimmys and shakes and the car would shake pretty bad when any sort of brakes were applied. Ive been 140 in a 3000gt VR-4 before and it was completely different. Its almost like the cobalt is too light of a car to be calm at those speeds. Where as in the VR-4 I could put of cup of coffee on the dash and leave it there it was that stable.

This was a fun experience and we tried to do everything we could to make it as "safe" as going fast could be. I would love to hear your stories, thanks for reading my first write up!

Sl0wbaltSS

I've done 148 in my old white SS/TC when it was completely stock. I don't even think a muffler delete. Maybe just the MPX antenna

footballplaya3k

iTrader: (1)

You must be short-shifting pretty early, I've gone 135 in 4th.

SiloGM

for some reason I feel like with my tune the power falls off SO bad after like 5900 or 6k that I just shift around then, I need to go back to the dyno and have the tuner figure some stuff out it just feels odd.

SR Tech

iTrader: (2)

I normally take 4th to 130+ aswell.

Devin86

Same hit like 150 100% stock me and a ls1 SS ran it out on this highway he was 2 ppl deep in his car neck and neck till we stopped. I don't really like going over 120-130 anymore tho just not worth it stock turbo lol

Sl0wbaltSS

2nd takes me to 70 mph
3rd takes me to 105
4th takes me to 130-135 depending on when I shift
and well 5th, 148 lol Don't have the tires to do faster or room.

SiloGM

looks like the next time we do this I need to hold 4th longer than I was, im not totally used to this new car yet, Im still used to my old LS1 Camaro.

Sl0wbaltSS

Shift at 6300-6400 since your rev limiter is 6500.

colodude18

iTrader: (4)

Konis and YYZ's will fix that "unnerving" feeling over 140.
My car feels rock solid all the way up to 165 which is when it hits the rev limiter in 5th on the 4.45 transmission.

sc4door

iTrader: (8)

Does anyone else find it strange that he only managed a little over 140 on a mile long stretch with a 90 mph rolling start?

LNFTX

Not really after 100mph you start covering ground quickly
What surprises me is how shaky the car was. Ive had mine bone stock up to 152 and it was smooth not sketchy at all took almost 3 miles though on the stock tune

sc4door

iTrader: (8)

I just think it's weird because this guy (was a member on here, can't recall his username) is high up in elevation and was trapping 135ish in a standing half mile. To only be able to only manage 140 in a rolling mile, just doesn't seem right

SiloGM

I'll be honest I wasn't shifting quick. And was loosting boost in between shifts I wasn't no lift shifting. And was being kinda skittish every time the car shook. I figured my car was being slow. I thought these things would be quicker in that amount of space.

SiloGM

It's also worth noting on the 144 run I had quite a bit to go left after whatever hit me. But I laid off because I wasn't sure what had happened at the time

sc4door

iTrader: (8)

Gotcha, I wasn't trying to bash you or anything, the top speed just seemed a little low to me

SiloGM

Na I know lol. The goal next weekend is 150. Just trying to be realistic. We're also gonna take my built LS1 camaro out and test that. Hopefully I have enough to buy a go pro before then. I would like to see 155 out of the SS but that seems like it's asking a bit much.

colodude18

iTrader: (4)

Mind you Mike was on a 25psi E85 tune at the time. He has since traded his Cobalt in for a CTS-V

tomj77

iTrader: (2)

Iv got to 160, seems like the high rise doesn't let it go much beyond that unless u got wind at ur back. Even with zfr. To much drag with that big spoiler

blueLNFftw

iTrader: (16)

160+

Cobalt_Daddy

143 here. felt fine.

tomj77

iTrader: (2)

I think that gt500 over estimated his hp a little lol