Oversized Throttle Body Upgrade - Satria GTi 4G93 TB Modification

12th September 2008

From the previous collection, I have posted the pics on my car engine major overhaul. After the overhaul, the air intake has been dramatically increased and the main restriction to the entire system would be the TB itself.

One of my friends adviced my to replace the TB to a larger size to optimised the engine performance. So I got this larger TB from a Satria GTi 1.8L which share the same mounting positions. But there is a little problem for this TB as the bottom harness socket is not compatible with my car. Well, this can be solved by just swapping the bottom part with my original one from the 1.5L version.

During the engine overhaul before, I already bypassed the water hoses into the TB. So there is no problems swapping the bottom end of the TB. If you notice the 1st picture, the water channels are not exatly the same for both TBs.

After the installation, the TB works fine without any idling problems. The only thing i need to do is to adjust the throttle able tension and adjust the idling screw to get the correct idling speed. Then some serious porting need to be done on the intake manifold to match the new TB port.

The results?? Matched with my other engine mods, this upgrade is simply amazing!! The low-end torque increased tremendously and the powerband had never been so great! Money well spent.

Wira MMC 4G15 (46mm) vs Satria GTi 4G93 (54mm) 800x600	A temporary gasket for the new TB. 800x600	Thanx to Drex who custom made a plastic cover for the bottom part of the TB which seems to be "melting". 800x600
The throttle plate and inner walls polished to bling! 800x600	Bling bling TB inner walls! 800x600	Another bling bling!! The inner walls polishing are done by my own fingers. 800x600
8mm difference in port size, resulting a 4mm circular restriction into the intake manifold. 800x600	This is quite bad if the throttle valve plate is opened slightly or cruising slowly. 800x600	This is the mark on the intake manifold after using a week. Time to do some serious porting. 800x600
My 1st attempt to port the intake manifold. Yeah! It works and the acceleration became smoother. 800x600	So far I only ported the bottom part. 800x600	The intake manifold is then polished till smooth n shiny for better airflow. 800x600
Surface is smoothen. Ready to be polished to mirror finish. 800x600	Polished with metal polish. Bling bling!! 800x600	Another bling bling!! 800x600
Second stage polishing for the TB inner walls. This time i use an electric drill. 800x600	TB back in place. 800x600	Here are the tools i used for porting and polishing. Soon, i'm gonna port the entire restriction to match with the TB port. Stay tuned. 800x600