For a long time I had considered the possible advantages of the ScienceofSpeed Big Bore Throttle Body. It seems that opinions on this modifications are somewhat divided. I had already added Taitec headers and had just mounted the Cantrell air intake scoop. With those mods, the car was revving very nicely with a mean sound added to it from the intake. I decided that adding a BBTB might not deliver any real gains in terms of horsepower but that it sure wouldn't hurt my engine in reaching its revlimiter just a little quicker. And a quicker revving engine should mean faster acceleration now shouldn't it. So I ordered the BBTB, sat back and waited. When the package came in out came a very shiny throttle body that looked like new. The butterfly valve especially was shining like a mirror.
For changing the throttle body only a few tools are needed. One or two screwdrivers, a wrench and a pair of pliers will do. The first thing to do is loosen the hooses attached to it. For this, screwdriver and a pair of pliers is all that is needed. The large air hoose is clamped so for this you need the screwdriver. The smaller hooses have a spring clamp on them. Squeeze the clamp with the pliers and you should be able to pull the hoose free without too much problems.
After the main air hoose is loose you have to remove the complete airbox. Loosen the four screws with a long screwdriver and remove the airbox. After that, there are four nuts holding the trottle body, two on top and two below. Loosen them with a wrench. Make sure that you loosen the lower hoose which can be a bit tight.
Pulling the top cooling hoose free will result in the loose of a little of cooling fluid. At first I was a little concerned about this but my mechanic said it was so little it would not cause any problems when starting the car.
After the removal of the four nuts you have to remove the throttle cable. This you have to do carefully to make sure you will not bend or damage it. With one hand, you can pull the throttle all the way open and then remove the throttle cable. It is attached in the same way as the door lock cable is attached to the door handle. After this, you can remove the complete throttle body.
The picture below shows the original throttle body compared with the Big Bore TB from Science of Speed. You can clearly see how the inlet has been machined out to a greater diameter over its full length.
Mouting of the new BBTB is as simple as removing it. I first cleaned the mating surfaces on the engine before fitting the BBTB. Also, there is not gasket to worry and the BBTB slides on easily. As is often the case, putting back the nuts, hooses and airbox was much easier than removing them. The final result looks like this.
After checking that I had not forgotten any hooses I started the engine and then check again for any leaks to make sure. Then, I double checked the level of cooling fluid and added just a little to make up for whatever I spilled.
Total time for this task was a little over an hour and taking it easy. It is absolutely not difficult to do. However, make sure you put some cover on the car to protect the paint as you are bending over constantly and also beware of your knuckles when working on the hooses.
And for those who are interested, the throttle body weighs 5.3 lbs (2.4kg).
The big question now on everyones mind is of course, did you notice a difference?
I had first planned on dynoing the car before changing the throttle body and then do it again after. Unfortunately, my car was not fully ready to drive at that moment so I did not have a change to do this even though I would be very interested in the results.
The car certainly revs very quickly but I cannot tell for sure if it does this any faster than before. But then again, even if it didn't help it also sure did not hurt :smile:
For changing the throttle body only a few tools are needed. One or two screwdrivers, a wrench and a pair of pliers will do. The first thing to do is loosen the hooses attached to it. For this, screwdriver and a pair of pliers is all that is needed. The large air hoose is clamped so for this you need the screwdriver. The smaller hooses have a spring clamp on them. Squeeze the clamp with the pliers and you should be able to pull the hoose free without too much problems.
After the main air hoose is loose you have to remove the complete airbox. Loosen the four screws with a long screwdriver and remove the airbox. After that, there are four nuts holding the trottle body, two on top and two below. Loosen them with a wrench. Make sure that you loosen the lower hoose which can be a bit tight.
Pulling the top cooling hoose free will result in the loose of a little of cooling fluid. At first I was a little concerned about this but my mechanic said it was so little it would not cause any problems when starting the car.
After the removal of the four nuts you have to remove the throttle cable. This you have to do carefully to make sure you will not bend or damage it. With one hand, you can pull the throttle all the way open and then remove the throttle cable. It is attached in the same way as the door lock cable is attached to the door handle. After this, you can remove the complete throttle body.
The picture below shows the original throttle body compared with the Big Bore TB from Science of Speed. You can clearly see how the inlet has been machined out to a greater diameter over its full length.
Mouting of the new BBTB is as simple as removing it. I first cleaned the mating surfaces on the engine before fitting the BBTB. Also, there is not gasket to worry and the BBTB slides on easily. As is often the case, putting back the nuts, hooses and airbox was much easier than removing them. The final result looks like this.
After checking that I had not forgotten any hooses I started the engine and then check again for any leaks to make sure. Then, I double checked the level of cooling fluid and added just a little to make up for whatever I spilled.
Total time for this task was a little over an hour and taking it easy. It is absolutely not difficult to do. However, make sure you put some cover on the car to protect the paint as you are bending over constantly and also beware of your knuckles when working on the hooses.
And for those who are interested, the throttle body weighs 5.3 lbs (2.4kg).
The big question now on everyones mind is of course, did you notice a difference?
I had first planned on dynoing the car before changing the throttle body and then do it again after. Unfortunately, my car was not fully ready to drive at that moment so I did not have a change to do this even though I would be very interested in the results.
The car certainly revs very quickly but I cannot tell for sure if it does this any faster than before. But then again, even if it didn't help it also sure did not hurt :smile:
I dunno, what do ya'll think?
