what is my speed ? help !

hi guys. i'm a newbie here driving a 180sx once fitted with a ca18det engine. ever since i did an engine swap over to an s15 sr20det together with its six speed gear box and stock ecu, i have experience problems such as very high petrol consumption, a power lag from 2000 to 3000 rpm and my speedometer cant seems to work. ive brought it to several workshops over in my country(singapore) but none of them know what is exactly wrong with the speed meter. some suggested to get it tuned while others recommend me to have change my speed meter panels to s15. another probable solution was to change the rear gear box to the s15 one with LSD as the s15 runs the meter from its rear gearbox.

does anyone here have encountered this problem before or know of the solution ? cos i need to fix this problem fast before the authorities in my country finds out about the engine swap. any help is deeply appreciated. cheers.

the s15 drivetrain has its speed sensor in the differential. you need to use the s15 trans and differential for it to work properly. how are you even getting a speed reading as it is? there is no sensor in the trans.

as for the power lag and fuel comsuption problems, i'm not sure. my work on turbo cars has been very minimal. maybe a boost leak somewhere causing you to run rich and spool late? maybe the s15 turbo just doesn't spool until 3000rpm, i don't know. maybe some other guys on here can help you with that one.

spitz is right. your going to need to use the s15 differential to get a speed reading. so I'm also not quite sure how your getting any speed reading right now....

As for the power lag problems, check all of your vacuum lines and make sure that they are all properly connected. If they are then I reccommend doing a basic tune up (spark plugs, plug wires, fuel filter, etc..) on your motor and seeing if that helps any.

thanx for the info guys. i think i will do a basic tune up on the spark plugs, plug wires and then see how it goes for the lag.

yep, i cant read my speed now on the road so basically just got to follow the speed of other cars and judge from the rpm readings.

you guys mention that i would need to change to the s15 LSD which mean i have to buy the entire s15 rear gearbox or the connecting axle as well ? kindda lost here, or do i have to buy the drive train as well ? spitz7985, u mention of s15 trans, as in transmissions? thanx. :)

you don't even have the s15 transmission? go to www.heavythrottle.com

i apologise for my ignorance, but what exactly is transmission ? read the website u directed but still unsure.

the thing between the engine and the driveshaft, with all the gears and the shifter

are you american?

oh i see. nope, im singaporean actually. i think i do have the the transmission. cos i bought the engine set linking to the gear box. but does it mean that i would just need to buy the LSD for it to work ?

i'm guessing that you didn't do the install yourself. is this a correct assumption?

what year is your 180sx? i think you have to be using the s15 driveshaft if you have the 6-speed installed, right? then yes, you do need the s15 differential. i don't know about the axles. e-mail the guys at www.heavythrottle.com and ask them. they'll know.

yep, i didnt do it myself.
its from the year 91. ok i will mail them. thanx a lot.
:)