Hello all. Some of you had asked for more information on this project following the car's debut at The Bash. My just-turned 17 year old son Adam and I have been flogging the car mercilessly in the weeks since, and the overall results have exceeded even my expectations, both for the car itself, and for him driving!
Initially, this car was run in 2003, with a best of 12.12 @ 118 mph. We've made many changes to it since then, most of which consisted of removal of items we deemed excessive in terms of complexity and expense. We removed:
1. Programmable DFI engine management
2. Super 20G turbocharger
3. Crane ignition amplifier
4. Seperate coilpack and wires
5. Nitrous oxide
This time around, we wished to show how to do the most with the least, and demonstrate the capability of our standard Stage II turbosystem on a mildly built Ecotec, using more boost than the stock engine will allow:
1. We used our new PortFueler system in place of the DFI, while retaining the stock computer and injectors.
2. A Super 16G unit went in (standard in our Stage I and II systems)
3. Stock ignition was retained
4. Stock coilpack retained
5. No nitrous!
In addition, the car was heavy in its previous iteration, 2900 lbs. with a 220 lb driver. Adam worked hard all winter in our home garage doing weight reduction. Anything he could unbolt that would not make the car race-only came off. I performed some plasma-surgery to cut another 20 pounds off non-critical areas, and taking off the heavy billet rear wheels in favor of lightweight Keizer skinnies helped too, for a new weight of 2600 with a 160 lb driver (it all adds up!). It's important to note that the car did not benefit from any exotic or expensive weight reduction, most of it achieved by a 17 year old following my directions. The car still carries a rollbar and full interior.
We also reduced rotating weight in the engine by removing the balance shafts using a nifty method we developed which retains the chain drive (essential, as it drives the water pump too). Beyond the Eagle rods and JE pistons, the engine is stock.
The Getrag 5-speed transmission remains stock, coupled to a ClutchMasters Stage IV clutch with stock flywheel, and DriveShaft Shop axles. RKSport lower control arms and Eibach lowering springs round out the minimal supension mods. We machined a trick ABS-eliminator block that also allowed us to plumb in a SSBC adjustable proportioning valve as well as a line-lock for burnouts. This also enabled us to remove the entire e-brake system, good for about 20 more pounds. In our part of the world (upper midwest), it's flat as a pool table, so the loss of the E-brake for parking was not a problem.
As Ecotec engines are stock with a plastic intake manifold, we did opt to retain the aluminum short-runner intake the car had previously when it was DFI equipped. Unlike some of our other PortFueler applications where we can add the four additional injectors with a billet plate between the head and the intake, Ecotec engines have their stock injectors in the head (rather than the intake manifold, which is much more common). This design prevents our plate approach, as there's just no room for the additional injectors. As we felt that any high-boost Ecotecs would be better off replacing the stock plastic intake for safety and enhanced performance, we simply incorporated the PortFueler injectors into our manifold. The manifold uses the stock throttle-body for simplicity and retention of stock IAC and TPS. We plan to offer this aluminum manifold/PortFueler combo to the public if demand proves ample.
We also wanted to demonstrate what can be achieved with unleaded gas and a catalytic converter. The car runs on 93 octane at low boost (up to 11 PSI), with 100 unpeaded at high boost (up to 22 PSI). One of our 3" HiFlow cats is utilized with a cool prototype side-exit exhaust (saves weight compared to going over the axle and out the rear). Like an SRT-4, it has no muffler, just the turbo and the cat to keep it street-quiet.
What's it all add up to? At the wheels, about 325 HP, so figure 370 or so crank. So far, we've run 11.87 @ 118 MPH, with a backup pass of 11.91. Yes, that's about .25 second quicker than the previous 20G-DFI-N2O iteration, with the same MPH. Miraculous? Well, keep in mind, we only made a few passes with the car in its previous setup, whereas with the current combo, we've made about 80, as well as a couple dozen dyno pulls. This time around, it's highly optimized, and a fair amount lighter.
It's now become our first-ever 100% emissions-legal 11 second car. That's significant, as we've been at this for a while, with Neons, DSM's, and many others. You could bolt the street tires on after an 11 second pass, drive to the test lane, and pass not only an OBD-II scan, but even the tailpipe anyalysis. Even the downstream o2 sensor stays happy, with no check-engine light thanks to the unleaded gas and cat.
Adam has done a killer job for a young fellow, with excellent reaction times and quick passes galore. The car works SO well, with a best 60 foot of 1.71 seconds. For a basically stock suspension, that's admirable for ANY car. It goes straight, doesn't sway or jump around, and has been wowing crowds everywhere at NOPI events as well as our home tracks with its performance and good manners. Keep in mind...this transmission now has about NINETY 11- and 12-second passes on it, as well as dozens of dyno runs, with no signs of trouble. We intend to swap in another unit soon so that we can take apart this exemplary Getrag for inspection and analysis.
Mission accomplished! Adam and I built this Sunfire to have fun, but also to prove to the world that there is great potential in not only our Stage II turbosystem, but the Eco 5-speed J-body as well. The props the car has garnered so far are many, from domestic and import fans alike, and we are far from done...
Now that we have run 11's with such a mild combo, the gloves are about to come off. Next we are chasing our own 11.70 second 16G turbo record that we set several years ago with a Neon. To achieve this, we are putting the DFI system back on, which will allow us to run as much as 32 PSI boost with the 16G. Yes, the cat will have to come off, as that's leaded hi-octane territory. If my calculations are correct, this should allow us to run in the 11.40 - 50 range, with trap speeds approaching 125 MPH. If all goes well there, then the Big Kahuna goes on...a Super 25G which will give us about 650 crank HP max potential. Can we run 10's with a street-legal J? Stay tuned...
Bill Hahn Jr.
Hahn RaceCraft
World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com
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