Hey guys, a few weeks ago I picked up a cheap mr2 for a project, and I'd like to give an n2o install a go. Has many people on this forum given it a crack? How can you tune the afr without a dyno or aftermarket ecu?
It's a bone stock 3sge 1991 sw20. Hoping to run just a 50 shot, just for a little bit more kick when I need it.
Cheers guys

50 shot hey, 50 days of fun.

ranga97
Hey guys, a few weeks ago I picked up a cheap mr2 for a project, and I'd like to give an n2o install a go. Has many people on this forum given it a crack? How can you tune the afr without a dyno or aftermarket ecu?
It's a bone stock 3sge 1991 sw20. Hoping to run just a 50 shot, just for a little bit more kick when I need it.
Cheers guys

 
You need a dyno and aftermarket ecu to run it safely, otherwise there is a high chance you will cause a lot of detonation.

If you are 100% set on doing a Nos kit, spend the money once, do it right. 
 
Also be aware that Nos kits are extremely illegal in all states (as far as I am aware), and even having the system in the car but not hooked up is illegal. 
 
 

Done it on plenty of cars, but not an mr2. Only way to do it at all reliably would be to get a wet kit, and a wideband gauge. As it is a cheap play around, knock detection can be the window wound down, and id suggest probably pulling 2 or 3 degrees out of the base timing (ie. Wind the dizzy back.)

Best person to speak to on here about nitrous would probably be kameleon

MCT_MR2
Best person to speak to on here about nitrous would probably be kameleon

 
Not knightrous?

TonyMR2
50 shot hey, 50 days of fun.

So 25 only equals 25 days of fun?
 
Thanks for the replies, as for aftermarket ECU's... any recommendations for a low-end/midrange model?

ranga97

TonyMR2
50 shot hey, 50 days of fun.

So 25 only equals 25 days of fun?
 
Thanks for the replies, as for aftermarket ECU's... any recommendations for a low-end/midrange model?

Probably an older Autronic would run it ok.

Is this a street car?

I once upon a time researched nitrous for my 3sge, but the cost was just way too expensive. 
To be set up fully you're looking at:

-Kit with bottle warmer etc etc $600-700
-Aftermarket Computer $400
-Dyno Time $250+
-Wideband $250+

Plus any extras

Then there is filling the bottle itself. Local places in Brisbane charge $16.50/lb and a $15 fee.... so for a 10lb bottle it costs $180 to fill it up... and you wont get much time out of that. 

Not trying to shoot down your ideas, just keeping it real. A lot of people try for bulk power cheap. Unfortunately, this is generally not the case. Unless you're Johnny from WA.

have you looked into doing a turbo swap or selling the car to buy a turbo? This would be a more cost effective means long-term and you will net more than 50hp.
 

Dudeman
 
Not knightrous?

I can't speak for Aaron, but Trav used to use nitrous on a lot of his old cars and played around with it a lot, so he is quite knowledgeable, and im pretty sure a lot of them were without engine management

50 hp shot :) try take out your spare tyre, reduce your fuel down to 1/4 tank, empty all non essential shopping items In your boot, swap your battery to a light weight battery, and feel the effects better than a 50hp shot of nos.

If your mathemetatics is 3sge has 177 Bhp (flywheel) 7000 rpm and a 3sgte has 221 Bhp 6000 rpm, therefore about 50hp difference - it's not that simple and the turbo will still be faster.

Unifortunately 50hp nos is a long way off a 3sge being fast and very close to disaster and fines.

Sensible changes alternatives, change your intake cam to a later generation (cheap if you can find one) or aftermarket cam. There are limits on what you can put in based on your valve springs/shim style. Get adjustable cam gears, dyno tune (advancing timing), lighten the flywheel. Get the car light. More fun wherever you want, sustainable and legal. Cost you the same as the nos, but a lot of time on the tools.

Cheap fast is short lived. Laws of engines.

You can do the above as tony said, or put some good tires and coil overs on it and beat half the field out there. you dont need power to go around corners fast.
 
As an example, Adrian can do a 1.10 arround Wakefield park in his 3SGE SW20 (Approx 130whp). I could only manage a 1.16 with 250whp.