hi i was wondering since im getting a sr20det installed into my 1990 240sx with greddy front mount, would i need to relocate the battery? im looking to go for a optium battery so it i were to get a smaller size would it be better or is there any other solutions, besides relocating in the trunk? and does any one know if i would have to relocate the windshield washer reservoir? if so where and how? thanks
You can potentialy leave everything where it is, you jus need to do your piping appropriatly. Put the battery in and make the piping around t. It can be done. Lots of people have their battery in the stock location with a fmic.
Putting the battery in the trunk can potenially cause a lot of headaches over technicalities at the race track. I’ll still probably relocate when I install my FMIC in the spring.
Do you have a FMIC kit? If so you will need to move the battery. If you have just the intercooler, then you can make your own piping and squeeze it by!
If you have a FMIC kit then you could relocate the battery, but a smaller battery will also work. I bought a yellow top Optima battery designed for a older civic. It’s very small and can be mounted sideways without moving my washer fluid resevoir, so the piping should fit no problem!(I haven’t accually installed these yet but they should work fine). Alot of people go this route, and it works fine for them, I didn’t want to give up some Electrical power when using a smaller battery, that’s why I went with the more expensive Yellow top, it should be able to handle the power demands of the car and a small stereo just as good as the old battey which was twice the size. However it did cost over $200 !!
it will fit without relocation! and i have the place to get the dynamite small batterys! they are small and still give u enough power to start in -30 if needed 
Part number is NS240Z. I pay about $65 for them and you can get them from any battery store unless there stupid and just dont want to help you out:S Mount it like mine. Here is pic
