#1
|
|||
|
|||
Using WI on RX7 Turbo 1991???
Hi everyone,
I'm new on this forum cause I really want to learn a lot about this technology. I have a Mazda RX7 Turbo 1991, and after some test of other persons it seams that water injection has a lot of benefit for the rotary engine and solves all his defaults...ALL!! So I'm really interest to do this on my car. My car has a complete setup for about 12 psi and 280hp with the stock Turbo and ECU. It has the APEXI SAFC NEO with stock primary injectors (550cc) and 880cc secondary. I would like to know first if its possible to install a WI kit on my car, even if I dont have a standalone? And which kit would be the best for me....considering that maybe in the future I wont stay with my stock turbo and engine management and go for bigger turbo with standalone to get about 400whp....because I would like to keep the same kit and just tuning it not to buy another one for my bigger setup? Thank you all for your help! Kenny |
#2
|
|||
|
|||
RX7 engine in a clamped engine bay can really do with any form of water injetcion cooling. You are right
In most cases, a simple on/off water injection system will be good enough, triggered abive a certain boost. Injecting at a rate of 10-15% water to fuel will not require a tune. Based on your total fuel flow of 2860cc/min, you can inject between 286 to 429cc/min. Looking ahead of future modifications where fuel injectors and turbo will be replaced. Once you have a larger turbo, your power range will be broader. For this reason, you need a progressive system, preferrably follows the boost pressure and RPM. WM system options: 1. Single stage system (SS-S): full spray after triggering 2. Double stage system (DS-S): A second nozzle is activated at a higher engine load 3. Progressive pump speed system (PPS-S): A motor speed controller progressively increasing pump speed to attain high line pressure to increase flow. 4. PWM valve system (PWM-V): Same principle as a standard fuel injection system, flow is controller by an inline valve. WM system availability from WM manufacturers: 5. Single stage: All manufactures make them 6. Two stage system: Often needs a second pressure switch added to the single stage system 7. Progressive pumps system: all manufacturers except FJO and Aquamist 8. PWM valve system: FJO (cell by cell) and Aquamist (IDC tracking) only. Not all the progressive systems are the same 9. A PPS system normally costs about 30% less than the PWM valve system. 10. A PPS (progressive pump speed) system cannot be compared to a PWM valve (similar to an OE fuel injection system) system. At best the dynamic flow range of a PPS system is x2. This calculation is based on a pressure change of 60psi to 240psi. For a "pressure change" of x4, you will only get x2 flow change. 11. For "PPS" system to work as well as a "PWM valve" system (at worse x10 dynamic flow range), the PPS system needs to have a pressure change of 60 psi to 600psi!!! 12. The other important factor most people missed is the response time to a load transient. A rotation mass as in a PPS cannot suddenly speed up and slow down. This leads to a delay in a "ramp up" and a delay in "ramp down". A PWM valve system response to load change in a "thousandth of" a seconds compare to "tenth-of" seconds. This leads to inconsistant AFR during load or gear change. .
__________________
Richard L aquamist technical support |
|
|