Combination Synergy
Following are a couple of drive train combinations that should work as described. By no means are these meant to be the definitive combinations of parts. These are merely examples. There are so many turbo varieties, etc. these days that it would be extremely presumptuous for me to say this is the absolute way to do it. Note that these are aimed at Daily Drivers, not race cars. These examples are offered with the assumption that the cars have been verified to be mechanically and electrically solid and have been set up as per the section Fix the Basics!!
Either one of these combinations should be capable of being driven regularly on the street reliably and hit over 20 mph on the highway with the AC blasting. Stop and think for a minute. How many legitimate street cars can run Tens and Elevens at the track while being driven daily on the street? Not that many as far as I know. Of course, this is all predicated upon the drive train being mechanically sound and the owner not being a complete idiot.
Someone once said there were a lot of turbo Buicks out there that were comprised of ten second parts that were running in the twelves because the owner was a fourteen second guy. My experience concurs with this observation.
I titled this page "Combination Synergy". That is because there has to be some thought put into buying parts that work together when installed. It is pointless installing a giant turbo on a car that has a stock torque converter as it will not want to make boost. Or a big turbo on a stock intercooler which will not willing flow the air that the turbo can push. All the parts selected must ultimately complement each other and this is particularly true on a car that is driven on the street. It's embarrassing to be be out run stoplight to stoplight by a Subaru because your car takes a block to build some boost. Think before you buy. Don't set out to build a Nine second car when you have an Eleven second budget. Observe others than have been in the game longer than you and see what is working for them. Don't be in a rush to make some one rich selling parts until you understand what you are buying and how it will work for you. Take your time and be a smart buyer. There are always someone waiting to sell your parts so don't get rushed into buying what may turn out to be wrong for you and your needs.
Personally, I believe the most important two parts of the combination are the turbo and the torque converter. Don't be persuaded to buy a converter from a specific guy because he is a great guy unless you have seen his converters in action and you know they will do the job you desire. Good converters will be closer to a $1000 than they will be $300. Save your money until you can afford to get the one you want. A good converter will spool your bigger turbo under load and give you the boost you need at the line, but, will still drive like a regular converter at light throttle on the street instead of slipping like crazy and giving you 3000 rpm before the car begins to move. The science of converters has really advanced in recent years.
I guess I should mention lock up converters (like the factory) and non-lock up converters. It is my opinion that street cars will do better with a lock up converter where as a race car will do better with a non-lock up unit. If I had to pick a time range, I would say lock up converters down to about 10.5 quarter mile times and non-lock up on cars quicker than that. It really depends upon your goals. If you are aiming for something closer to a Nine second car, then non-lock up is the way to go.
With regard to turbos, don't be tempted to buy a cheap unit from overseas. The explosion may be spectacular. Again, wait and save your money. For street or track, a conventional, cheaper journal bearing turbo will work well when matched up with a good converter. Look at what is working for others and save your money until you can do it right.
The first two things to do before modifying your car for more performance is to be sure the timing chain has been replaced and that it has also had the valve springs replaced. It does not matter if the car has 10k on the engine or 100k. This is vitally important if you expect good results as well as to avoid disaster.
Version 1-Upper Elevens
A 2.5" free flowing exhaust kit
An open K&N air filter
A PowerPlate that matches your plenum
A modern programmable chip. I like the ones that are designed to be driven by the wideband O2 sensor I suggested in the Fix the Basics!! section
A 5831 turbo (has superceded the TA49 or
TE49)
A stock torque converter should work with this turbo if
you tweak the tune on the chip a bit but a converter that stalls around 2600 may
give you a bit more
A set of 60 lb injectors
A single nozzle alky kit
A set of 275/60-15 drag radials (Surprisingly, a number of
people do quite well with 255's--The 275/60 gives you a 28" tall tire which may
help you at both ends of the track.
When you can afford it, ported iron heads, an after-market stock location intercooler, and a 3" downpipe will make it easier to get the times down and will definitely benefit you when you decide you want more.
urbo Note: These are old scho1 which gives basically the same performance...don't get confused by the array of options...you don't need anything ultra-fancy in this range.
Version 2-High Tens/Low Elevens
Version 2-mid Ten Potential
A PowerPlate
An open K&N style air filter
A 6262 turbo (journal bearing will be fine)
A 3200-3400 rpm stall torque converter. Tell your
converter manufacturer what your combo is and he should be able to suggest the
correct stall in his converter
A set of 60-80 lb injectors
A single nozzle alky kit
An aftermarket stock location intercooler
A set
28" slicks
A 3" downpipe
Ported iron heads
A mild roller cam with a duration of 210-212 degs at 0.050" duration
Absolutely no need for aluminum heads in the tens.
At the sake of being redundant, these cars are all about combination and there are no magic parts-only parts that work well when complemented with other parts that match up. This includes the engine, transmission, and suspension.
I want to say a few words about intercoolers. In recent years, there has been a move back toward stock location intercoolers for cars spraying alcohol. This year, there were cars knocking on the door to the Eight's with stock location intercoolers. I am pretty sure that there has been some porting done on both inlet and exit sides to minimize pressure drop across the core. I know on one that is the case for sure.
Now, there is a common misconception about intercoolers. We tend to envision air flowing across the core and pulling heat out while the car is going down the strip. This simply not how it happens in drag racing. Instead, the intercooler core acts as a big heat sink and the hot air temperature coming out of the turbo is absorbed by the aluminum mass of the intercooler and the actual temperature increase coming out of the intercooler is not tremendously significant. Also remember that alcohol is essentially a chemical intercooler as well as a fuel.
When the car is on the return road and in the pit is when the core is cooled down by a fan, or other means of pushing air thru the core. This seems to be hard for some to understand, but, at least a couple of guys running in, or near, the eights have shown they can block the inlet to the intercooler so no air is being pushed across the core and the measured charged air temps coming out of the intercooler are the same as when air is allowed to pass thru the core on the run. Some refuse to believe this but the logged numbers don't lie.
Another benefit of using a stock location intercooler is that with the smaller volume and shorter plumbing, the engine is more responsive to the throttle and it is easier to drive the car consistently on the track and less lag on the street.
The giant front mounts weigh more, cost more, and make coolant temperatures higher when driving in warm weather areas on the street. Again, Note that I am talking about cars that can easily be driven reliably on the street and spraying alcohol to get the boost up to the FUN level.
Turbo Note: There are manause it is a proven unit that will provide great results. Do your research and don't get conned into a turbo that can run Nines just because someone gives you the old, "you won't have to upgrade again" line. The large majority of people will probably never dip deeply into the tens and will never be beat on the street so use some common sense. Get a turbo that spools fast with a tight converter that will provide great drivability and response on the street. These cars are a blast to drive when the combination is right.