MY NOTES ON TURBOCHARGING
This should answer some of your questions regarding turbocharging your car and would save people especially newbies asking the same old turbo questions again & again.
Engine
Normally aspirated engines are not happy with the heat and pressure of turbocharging. You need to lower the compression to a level manageable by the engine and ignition control you are using. Generally 7.5:1 to 8.0:1 will do what you want on today's terrible pump gas.
Pistons and Rings
Always use Forged Pistons that are properly designed for the engine you are building. We use JE Pistons and Total-Seal Rings in all our engines. If you cannot afford the forged pistons and you are building an engine that has a factory Turbocharged equivalent then use the factory Turbo pistons. They are never all that great for serious duty use but they are a good affordable alternative to normally aspirated high compression pistons. We use Total-Seal rings because they have proven to keep all the power in the cylinders and minimize blow by under hard boost conditions.
Block
Generally the block is fine for streetable boost levels. Very high boost pressures or race applications are a different story. If a steel shim gasket is available for your particular application, use it. They are expensive but well worth the money.
Cylinder Head and Porting
Good quality valve jobs and Stainless Steel valves. If Stainless Steel valves are not available or not in your budget at least get the stock ones high heat coated. This is generally inexpensive and will extend the life of the valve considerably. Porting varies with the head and engine. Generally for most street applications a nice clean up port with most of the attention being paid to the bowl area around the head of the valve and good match porting of the manifold and head surfaces. We try to do a high polish on the exhaust port to promote exhaust flow and minimize buildup and a swirl finish on the intake for better fuel atomization.
Ignition Timing Control
This is the key to Turbo cars running on pump gas. You cannot use a normally aspirated ignition distributor or engine control for a Turbo application. You will detonate and hurt even the best of pistons and rings. Most factory Turbo cars have excellent ignition systems with very conservative timing curves that are great for higher boost applications. If you are doing a normally aspirated to Turbo conversion you need to either incorporate the ignition into your fuel injection or use a timing control such as an MSD or JACOBS to insure you have proper boost retard for the level of boost you are running.
Fuel Management
We do not believe in turbocharging any car without it being Fuel Injected first. Yeah, we know it's not impossible to have a carbureted Turbo system, we've even done it ourselves plenty of times, but it will have drivability and heat problems not to mention float and seal failures ( Just ask someone that owns a Maserati Biturbo ). Programmable management is really the answer to a simple and effective installation on a normally aspirated car. We use either the Electromotive TEC-II or the HALTECH F9A units. Retrofitting a factory F.I. system into a normally aspirated car or into a car with a different style of management is not impossible but it is very complicated, so be sure and have a very good working knowledge of the cars electrical system before undertaking such a task. We recommend an on-board air fuel ratio monitor in all applications to make sure you do not lean out the engine under boost and put big holes in things. We use the HALMETER AF/30. It is almost always necessary to install a larger volume high-pressure fuel pump and some form of Boost Referenced Rising Rate Fuel Pressure Regulator to insure proper fuel delivery under boost.
CARB to TURBO EFI
Ok if you want a turbo, you need to do the
EFI SWAP.
The next step after you convert to EFI there's a shitload of things you need to consider,
firstly the condition of your engine. How many km's has it done? Is it blowing smoke? How much boost does the stock pistons, rods handle? - To answer that, generally the accord stock would be safe around 5-6psi at the most, I wouldn't push it anymore. And if it's a really heavily used motor, well...look to a rebuild with forged pistons, and all the other crap.
How much boost do you want to go? anything beyond 6+ look to rebuilding your engine first, secondly look at upgrading the fuel delivery, injectors, pumps, FPR, etc. The last thing you EVER want is running lean, you run lean and BOOM! there goes a piston, or worse.
Your transmission, the accord transmissions from what I've gained are all right for their stock purposes but aren't that strong. I know Justin ( 88Turboaccord ) has been through a few 5spd manuals. So with these if you want to avoid that, perhaps rebuilding it with stronger internals may be a way to go. I don't know how the gen2 prelude ones are like, but a promising option is rebuilding the accord 5spd with the internals from the Integra. I wouldn't want to turbo an accord running the auto, quite frankly our auto's are pretty crappy, and weak. Plus 5spd manual is more fun...but if you want to go that route, then perhaps look into putting a high-stall torque converter and maybe rebuilding the transmission.
Next, the turbo you want, best to go T3, I reckon the Mitsubishi TC05 or TC06 would be a good option. Those are the turbos off the Australian spec Starion and Cordia. I got a TC06 on my other car, but a TC05 that spools a lot quicker, I think boost falls off though above 5500rpm on the 2ltr Starion, but it would be ideal for an accord.
Next a turbo manifold, since an aftermarket turbo kit was never developed for the accord, you need a custom made manifold, and they can get pricey depending on what you want. So get a few quotes.
Other things you need to look at, tricking the stock ECU as it doesn't like boost that can be done through by generally bleeding boost pressure off the MAP sensor through the use of check valves. But an option with more tunability is definitely an aftermarket computer, like a Haltech, Microtech, wolf3d, etc. Do some research.
And definitely look at trying to do a lot of the work yourself, you'll save plenty of cash.
Even though I'm not doing any serious work on the accord, my Starion is keeping me busy and I'm learning lots of good new shit, but if I've had to even get a half of it done by someone else I'd be up for some big $$$ already, and that's only for basic shit. Things like engine and turbo rebuilds, etc I wouldn't touch, not unless you REALLY know what your doing, and have all the right tools. Otherwise, leave it to someone who knows what they're doing, coz if you fuck up! well....you know.
So yeah...that's it.
I probably missed a few things, but if anything else, just ask the people on this board, Justin and Sean are the foremost turbo experts.
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