Filed under: Aftermarket, Tuners, Coupes, Chevrolet
Mind you wrists: Synapse Turbo boosts Chevy Cobalt SS to 371 whp, 383 lb-ft
Click above for a gallery of the Synapse Turbo Chevrolet Cobalt SS
Within 20 minutes of taking delivery of a Pontiac Solstice GXP last year, we were on our way to our local shop to see what mods could be done to the turbocharged 2.0-liter four-pot. With 260 hp and a claimed 260 lb-ft of torque (our dyno run showed around 250 lb-ft of twist at the wheels), the Solstice is hardly lacking for grunt, and when we finally got around to driving the Chevrolet Cobalt SS, we were sure that the new engine would be embraced by power-hungry tuners in short order.
Scotia, NY-based Synapse Turbo has taken up the task and created a bolt-on kit for the Cobalt SS that puts out 371 hp and 383 lb-ft of torque. From what we can gather based on forum postings and the video after the jump, the Stage 3 kit consists of a Garrett GT2871R turbo, stainless steel 4-1 exhaust manifold, three-inch downpipe, three-inch intake, TurboXS BOV, a new intercooler and aluminum plumbing. ECU tweaks were provided by the HP Tuner system and redline has been raised to 6,700 rpm. We're itching to get some time behind the wheel, if for no other reason than to see if our wrists can cope with the torque steer, but until then, the video below the fold will have to do.
Gallery: Synapse Turbo Chevrolet Cobalt SS
[Source: MotiveMag]
Reader Comments (Page 1 of 3)
Hanoi Jane 11:08AM (11/15/2008)
Interesting video, that car just flies.
Here's my question, obviously that Cobalt is speeding, so the driver is breaking the law, so my question is who was the genius in Cobalt who took a shot of license plates of that GTI (if i am not mistaken). Also, why would you speed on public road and put the name of you company on the video, just do it at the track.
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happy_penguin 11:23AM (11/15/2008)
You have no idea how fast the car is going. Speeding or not, there is no official witness. Good luck getting that video to stand up in court.
aaron 12:30PM (11/15/2008)
You're more of a buzz kill than Buzz Killington.
Torrent 1:30PM (11/15/2008)
Stop hatin, Gabagool.....
I mean Hanoi Jane.
James Sonne 2:16PM (11/15/2008)
Actually, it would be very easy to determine the speed of the vehicle in the video. All you need is to identify the size of any object in the frame, such as a road sign, sewer cap, or the vehicle itself, and use that to create a virtual yardstick to which the car's motion relative to a stationary point can be measured between frames. You then have an instant velocity for any instant in the video or as small a period as 1/24th of a second. It's an extremely simple thing to do, and no "official witness" made-up legal jargon is needed.
happy_penguin 8:26PM (11/15/2008)
OMG what an engineering nerd. ;)
That's fine and all, perhaps possible. But I still stand behind what I said. It's not going to happen. :)
nist7 11:18AM (11/15/2008)
Wow.....couldn't they have picked a different exhaust system? That sounds exactly like all the other ricers with their coffee-can/weedwhacker exhaust...lol
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Paul 4:44PM (11/15/2008)
The exhaust on this car is stock
times2 11:28AM (11/15/2008)
Exhaust sucks... get an RPi. As for the engine, Solstice tuners already have this thing past 450whp.
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Cameron 11:36AM (11/15/2008)
Beautiful manifold work, and nice to see that they didn't butcher the bumper to fit the intercooler.
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bill jackman 11:39AM (11/15/2008)
Every time I see people like this "testing" on public roads, I cringe. Take it to the track, dbags.
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JeSuZ CicLe 11:50AM (11/15/2008)
Sorry, no matter how much i wanna give respect to the cobalt, i just cant shake the thoughts of all the kids from high school with cavaliers that thought they were sports cars, and riced them up. For godsakes our family minivan is faster than those d- bags.
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That One Person 5:08PM (11/16/2008)
hahaha those same d-bags try drag racing me in my 94 Regal. It's pretty hilarious when I beat them.
I guess those stickers really don't add power :)
why not the LS2LS7? 11:53AM (11/15/2008)
They increase the HP 50% and don't put in bigger fuel injectors? Thus must be an area where direct injection differs from regular fuel injection.
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Tourian 12:33PM (11/15/2008)
That might exactly be the case. Maybe the aftermarket companies haven't developed them yet. That kind of stuff is above the level of most tuner shops and generally comes from Denso, RC Engineering, PTE, etc...
zamafir 1:19PM (11/15/2008)
Yup, very odd, granted it's apples and oranges, but all the kits for VW's 2.0T incl new injectors:
APR's 355hp/368 torque has 'em
APRs' 382hp kit has 'em
Hell everything on the vw side, all the tuners, up to the 600hp kits for the 2.0T are using new ones
I'd be curious to see why this engine doesn't require upgraded injectors
Steve Bennet 1:38PM (11/15/2008)
The injectors run at incredibly low duty cycles, around 25% at wot. Plus the fuel pressure is at 2200psi, this increases their size greatly.
why not the LS2LS7? 4:36PM (11/15/2008)
25% of what? Do you measure against valve open time even in direct injection?
Overall 25% duty cycle would mean they're open the entire intake stroke, which would not be low at all.
25% at what revs? At higher revs the duty cycle usually goes up.
Given that the HP is less than the torque it would seem to imply either the injectors are maxed out at high revs or the turbo is running out of puff. Given that this includes its own replacement turbo, I find the latter kind of unikely.
Steve Bennet 5:45PM (11/15/2008)
What do you mean 25% of what? An injector that is fully open runs at 100% duty cycle, these di injectors run at around 20-25% on a stock car and 25-30% on one with a bit more boost on the stock turbo.
Injector pulse width is around 5-6 msec.
why not the LS2LS7? 6:35PM (11/15/2008)
I mean 25% of what.
Duty cycle is the ratio of on time to total time. What is the total time? The entire 4 strokes? If so, 25% duty cycle is the MAX possible, not "very short". It would mean the injector is on for the entire intake stroke (which is 25% of the total 4 strokes).
In a regular injected car, you can measure duty cycle against the intake valve open time (since the injector firing when the valve is closed doesn't make sense). 25% wouldn't be bad by this measure.
But measuring "true" duty cycle against the entire 4 strokes, 25% would be the maximum for a regular injected car (as the injector cannot be on during the compression or exhaust strokes). Although a DI engine could fire a bit longer, since it can fire during compression stroke. Either way, 25% cannot be considered "very short".
At 6500rpm, 6-7 msec would be about 66% duty cycle, which isn't really possible. It's more than the entire intake and compression strokes (even counting the time after the spark plug fires before you reach TDC).
If this is firing 30% of the time, it's pretty much maxed out. If it's firing 6-7msec, then it explains why the power drops at high revs. The pulses are already maxed out and have to be shortened due to the short stroke times, dropping power and making the car run lean if the boost isn't dropped too (ow!).
So, at 6-7msec or 30%, sounds like it's time for a higher pressure fuel regulator or bigger injectors. Then the torque can stay up at high revs and raise the output.