1.7 or 2.1
 

i have a 88 T2 with a bnr stage 2 s5 trubo and a street ported engine. I was wondering if i could go with the 1.7 and use the 750 cc secondary and be able to up the boost a little or if it would be better to go with the 2.1?

2.1 without a second thought

You can do whatever you want.. Aftermarket turbo, and aftermarket fuel setup I'd go with something that is 'tunable' (as I have). 1.7 would probably be ok, but 2.1 would allow you to KNOW its ok. Or at least have a better Idea whats going on.

Or, go with 1.7 and cross your fingers, but if it goes lean under heavy boost(+10psi), your going to be getting a buying and installing a new set of apex seals possibly.

With 2.1 you can richen it up then pull fuel and adjust the timing too (do some actual tuning).

Almost everyone here will probably tell you 2.1... but it's your money and your car... What do you feel safe running?

Shameless thread plug - https://www.rx7club.com/rtek-forum-168/afr-tuning-methods-827389/

how hard is it to tune it your self also. if i was to go the 1.7 rout would i be fine if i didnt go above 10+?

would this aem wide band be able to work with the rtek even though it doesn't have a gauge ? http://www.aemelectronics.com/index.php?cPath=15_36

I'm running a PLX SMAFR w/o a gauge and logging it on the palm. as long as it has a 0-5v output you should be able to log it and view it correctly. It sounds like its exactly what you want, but check out PLX, it has worked for me...

Yes that will work.

well looking over everything i think i will go with the 2.1 but one last question how hard is it to tune with it?

Dude, you have to be a rocket scientist to figure it out. Like, it's not for little girls. I could barely figure out how to get in my car let alone plug in the ecu and turn the key.

No, wait, you have to be a nuclear scientist.

Really, its not that hard, unless you can't tie your shoes... Then I dunno...

https://www.rx7club.com/showthread.php?t=827389

thanks for all the help i will probably get one here soon and start messing with it.