Running Lean, 4G63 Build and More - Import Tuner Magazine

Facts you might not have known about Eric Hsu:
1. Your car has keyless entry. The code can be either one of Eric Hsu's fists.
2. Eric Hsu can sit in the driver's seat of any car, and by holding its steering wheel firmly in his left hand, and placing his right index finger at a point on one of its visors, increase its torque output by 367%. Permanently.
3. Eric Hsu is invisible to radar.
4. Some tuners love C16. Others swear by E85. Eric Hsu likes both, but Q16 is his pick to pair with a rare steak.

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questionit@importtuner.com
and put your helmets on.

Leaning Out
I own an '00 Integra with basic bolt-ons that include an intake, header, and exhaust. She has about 125,000 miles and has been running lean on bank number one. My friends and I have attempted to spray water around the engine while running to see if the problem was caused by a vacuum leak, but nothing turned up. Could the culprit be a faulty O2 sensor or a bad catalytic converter? I figured I'd ask the pros before buying any replacement parts I might not need.
-Ahmad Carter
Duluth, GA

The first thing to do is to check the engine's compression with a compression tester. While the spark plugs are out, you can do a good old-fashioned plug read to see if they are all similar in color. You mentioned "bank number one," but there's only one bank on an inline-four engine. If it does really say "bank number one" then it is likely that the short-term fuel correction and/or long-term fuel corrections are beyond the ECU's ability to correct. You can view these OBD-II parameters in real time if you have a capable scanner. This problem could be caused by the modifications you made to the car or a sensor issue, such as a bad oxygen sensor, bad air flow meter, or other mechanical issue like a collapsed catalytic converter or a faulty injector. Unfortunately, there's no way to correctly diagnose the car via magazine, so I would recommend you take the car to a knowledgeable mechanic for a proper diagnosis.

Low-Compression Build
I'm building up a 4G63 engine for my Eclipse GSX and I have a couple of questions: I'm looking to stroke it out to 2.3L but all of the stroker kits I've found are rated at either an 8.8:1 or 8.5:1 compression ratio. I want to get closer to 8.0:1 for my turbo setup and it's looking like I will have to buy pistons separately to achieve my desired compression ratio. Do you have any suggestions on the parts I should buy? Also, do you know of a good place to get a JDM steering rack? I want to do a RHD swap into my GSX to make it somewhat unique. The best I can figure is that the steering rack out of a Mitsubishi FTO will work because they have relatively the same wheelbase.
-Marc
via importtuner.com

What was the determining factor that made you decide that you must have an 8.0:1 compression ratio? I'm not saying it wouldn't work, just wondering how you came to that decision-8.5:1 should be fine. If you really must have a 8.0:1 compression ratio, the easiest way might be to buy an off-the-shelf 8.5:1 piston and then have an automotive machine shop take some material out of the dish. A good way to do this and to improve the piston is to increase the radius and depth of the valve pockets to increase the valve-to-piston clearance (especially if you are running bigger valves and cams). This way you can kill two birds with one stone. I don't recommend the RHD conversion because that would be a serious clusterfuck. I'm pretty sure all Eclipses were sold as LHD cars all around the world. But if you must have an FTO steering column, you might want to try some of the JDM engine suppliers in your area.

Blow-off Surging Dilemmas
I own an SR20DET-powered S13 using 480cc/min injectors, a GT2560R turbo, Walboro 255lph fuel pump, Nismo fuel pressure regulator, front-mount intercooler, HKS SSQ blow-off valve (BOV), Z32 MAF sensor, and tuned ECU. The engine is encountering compressor surge at low rpm. I can hear an erratic "whooshing" sound coming from my air filter and not the BOV. The engine surges at around 3,000 rpm and beyond when I shift from First to Second off boost. Interestingly enough, I notice no surge under full boost and checked my vacuum lines repeatedly to verify the manifold vacuum is at proper vacuum at idle. A lot of people I've talked to say it's OK for the HKS SSQV to surge at low rpm, but I can't stand the sound because I'm afraid I'm going to kill the turbo. I should also note that the BOV is connected to the fuel pressure vacuum hose. Does it affect where I install the BOV and do I need to install it closer to the throttle body?
-Cynthia Padilla
via importtuner.com

It sounds like your SSQV isn't opening around 3,000 rpm. Unfortunately, the jam nut located on the older models wasn't designed by HKS for preload adjustment. The screw was designed to supply a better seat if it was found to be leaking at idle; tightening it with intentions to increase pressure can damage the internal valve. The Garrett GT's bearing section is plenty strong so you're not going to damage it at 3,000 rpm with moderate levels of boost. Race cars with Garrett GT turbo(s) that rev to 9,000 rpm and run over 40 psi of boost sometimes don't run BOVs. One thing I recommend is that you run an individual vacuum line to your fuel pressure regulator that is as short as possible. This ensures the fuel pressure regulator responds quickly to throttle transients to provide adequate fuel pressure during the ECU's acceleration enrichment events.

Injection Selection
I want to boost my '87 Celica GT. The engine is stock except for an HKS head gasket. I was interested in installing a 3S-GTE turbo and manifold assembly, along with a set of 320cc/min injectors from an MA70 Supra. Can this setup run with the factory ECU?
-Jesus Alberto Alvarez Huerta
via importtuner.com

No, the stock ECU is only designed to run a stock engine with stock injectors and only in stock form. The cheapest way to get around the stock ECU would be to use a Vortech or Blox Racing FMU and a high-pressure fuel pump. This combo will spike the fuel pressure to compensate for the addition of boost. Older cars like yours can benefit from piggyback fuel controllers due to their lack of closed-loop correction factors. So for additional fine-tuning, you can also use an A'pexi AFC-Neo or a Greddy E-Manage.

Project Horsepower
I just bought an '08 Mazda6 2.3, and was wondering what size turbo I should select to make between 400 and 500 whp. I've just started this project and know I need plenty more parts to complete this build. Could you help get me started on intercoolers, turbos, wastegates, blow-off valves, etc., and who makes them?
-James Poff
Ft. Riley, KS

The answers to your questions can fill an entire book. The budget and scope of your project really needs to be determined before I can answer them. But to start, talk to the people at Focus Sport and Tri-Point Engineering for Duratec and MZR engine turbo kits, respectively. You may be able to adapt some of their components to your project. Good luck with your build.

Frankenstein Engine Build
I came across a forum thread discussing the Frankenstein G23 motor build, which consists of an F23 block and H22 VTEC head. I decided to build my own G23 and retain the stock bottom end but build the head with Blox valve springs and retainers, JDM Type-S cams, and a Cometic head gasket with ARP head studs. I ran into problems trying to change the pulleys and just about ran out of money. Do you know anyone that would be willing to finish the build for me?
-Dewey Stafford
Perris, CA

Your first step should be to log onto importtuner.com and search for "G23", to find the Feb '09 issue with 2NR's tech article on how to build a G23, its benefits and drawbacks versus popular K-series engines, the parts you'll need to do so, and who to contact for guidance. But in all honesty . . . if you ran out of money, how do you expect to pay a shop to finish the car?