Hi there, having discussed this a number of times it's now something which needs to be sorted.
Astra MK3 SPI 1.4, to convert or not to convert...?
To clarify first
1. its for road rallying so twin 40's not permitted.
2. i run in the 1400cc class.
Right, im sure you can guess the problem, the SPI is crap basically.
nova sr 1.4 with no cat and a carb = 75bhp
my car with spi and cat = 62 bhp
Thats 13bhp loss. So, is this mainly due to the spi or the cat?
1. change to a twin choke weber, easy conversion and cheap but how would the cat react when it was replaced for the MOT? would it work correctly enough to pass emissions?
2. change to mpi, quite a pain to do, have to change head, ecu, loom , airflow meter etc... not good fun tbh, especially the loom.
3. keep the spi setup and try to improve it somehow... would using parts from the 1.6 spi unit help anyhow in getting more juice in there?
4. Rip the whole engine out and replace with a pre 1992 jobby that doesn't require a cat for the MOT. If i did this would i have to prove the engine was older... or would the tester have to prove it was newer and should have a cat?
How much power will i gain by replacing the whole exhaust system for a performance jobby?
If any of you can make any sense in what ive said please comment.
btw is it possible to chip this model?