Driving Impressions, 3sgte with Gt28RS Options

[jgreening]

Well, I have had my car with the new turbo for 3 full days and I thought I would give you all my impressions so far.

First, the turbo completely changes the character of the car. With the ct-26 on the 3sgte, the car felt fast - alot faster than the 5sfe. However, even at 14psi, the car was "within spec". I think Lagos said it best when he said its the engine that should have come with the car. There is plenty of power to pass folks without downshifting. The ct-26 gives the car very nice torque down low and is fairly responsive. With the gt28rs, the car just feels angry. Stomp on the gas in any gear and the car completely wakes up and growls throwing me back in my seat like I didn't even imagine. At any place in first or second, wide open throttle spins the tires WITHOUT use of the clutch. Today I spun the tires in second gear at 6000 RPMs just by pressing on the gas. In all candor, I am afraid of the car in some ways.

Second, the difference above 5500 RPMs is stunning. With the ct-26, the power and torque drop off is so pronounced that an upshift is prematurely REQUIRED before redline. For those of you with 3sgte's, you know what I mean. With the gt28rs, the car pulls all the way to redline, peak torque happening a little later than the ct-26 but spool to 200 ft/lbs actually sooner. The power band is over 2000 rpms wider and this point cannot be understated. Despite the broader power band, the shifts are much faster - even at about 50% throttle due to how fast the tach moves. Its amazing the amount of air that gets pushed through that little T25-size turbo.

Third, and this was the biggest surprise of all, is performance downshifts. If I am cruising at 45mph in 4th gear and drop to third and punch it, the experience is absolutely breathtaking. I have heard others talk about bigger turbos feeling like you got rear ended when boost kicks in. I can say that the experience of the GT28RS is similar when downshifting. I actually moved my seat one notch closer to the steering wheel so I can keep good control of the car when this happens.

Today I turned the boost up to 17psi for a bit just for fun. The car felt so powerful that I flat out did not feel safe. I turned it back down to 14psi almost immediately just to tame the thing.

Given this experience, I can't even imagine what a 350+ hp engine in our cars would feel like. I estimate that I am somewhere in the 260 whp range at 14psi and I honestly can't imagine wanting more any time soon.

This post has been edited by jgreening: Dec 1, 2005 - 1:55 AM

[jgreening]

My tuning is nothing. I have 540cc injectors on a stock AFM and JDM ECU. The car is rediculously rich in closed loop but actually pulls AFR's in the 11's under WOT in 3rd and 4th gear. I was very happy about that. While going to a standalone or even a ROM tune from ATS would probably give me 20 extra whp and alot better milage, I don't think I will.

The turbo kit is a bolt on and can be installed by any competent person with a wrench. It is made by Carl Crawford at speed-source who is truly talented. He is placing it in production and will be taking orders. It includes a 3" ceramic coated down-pipe. He uses silver soldered hard water lines which look and perform like OEM. The manifold adapter in the production kit will be CNC machined (although mine is the prototype) and ceramic coated. The adapter has an offset center section so that the stock 3sgte heat shield can be maintained which is a real bonus IMO.

Information about the GT28RS or "disco potato" as its sometimes called can be obtained from the Garrett or ATP's website.

When my boost controller is "off", I run 14psi. I would need a different spring to run less which I might go to because the boost controller is almost useless in the current form. I would like to run this thing at 10psi for daily driving just for sanity and safety reasons. I am not sure a new spring would be effective though since the gt28rs is internally gated and, with the full 3" exhaust, I am not sure if enough exhaust gasses can be diverted through the wastegate.

This post has been edited by jgreening: Dec 1, 2005 - 1:23 AM