i just bought my first grand national a week ago and i have a few questions about it. first i noticed when looking through cold air intakes that you can fit an LS1 MAF sensor on it, does anyone have this on there GN and if so is it worth the money? second how much PSI can the whole stock engine safly take on the stock turbo, in other words am i going to blow something the minute i adjust the boost? finally my friend said i could but a blowoff valve on it i doubt i would ever do it but i just wanted to know if it was possible
Congrats on your new found joy!
First of all YES,..you can use a LS1 MAF, However youll need the translater you can find info here:
http://www.gnttype.org/techarea/ecmsensors/translator.html
Second, You can put as much as 25 psi of boost or more in it as long as you have the fuel to go with. Another words you'll have to modify your fuel system.(stock MAX boost 14 psi) The first thing you should do is buy a scanner of some sort. I.E. "Turbolink" so you can tune the car the way it should be. (and a few toys such as an adjustible wastegate and Fuel pump/regulator) you can find that info here:
http://www.turbo-link.com
You'll also need to do a little studying on
"How-to" Tune/tame your beast you can learn alot from this link:
http://www.gnttype.org/techarea/recipes/recipepage.html
Just remeber never get hasty,..thats when you start blowing stuff up...just take your time and get to know YOUR CAR, there all different in alot of ways and when you wake her up you'll know it! real damn quick!!! You might even need some clean shorts afterwards..lol
GOOD LUCK!
thanks man ill be sure to check those sites out
IMO, the T+/3" MAF is worth the money, particularly if your stock MAF dies, as mine did. (Some would argue that it is worth going to the 3" (or 3.5") setup BEFORE the stocker dies, considering the lack of availability of the stocker. Then just hang on to it for the smog tests.) After trying 3 stockers, all of which were horribly off on the calibration, I bit the $$ bullet & went with the T/3". ~1 year later, I sold the T and went to the T+ for the additional adjustments. Having adjustability of base spark & fueling, and separately WOT spark & fueling has been very nice to have.
Dean
Just to clarify what Mick said, "Second, You can put as much as 25 psi of boost or more in it as long as you have the fuel to go with" AND you aren't getting any knock. Going by the formula for fuel pressure, base = 40, then if running 25psi of boost, you want 65 psi, even if you are getting the right amount of fuel pressure AND you have injectors that can flow that amount, you aren't safe unless you have the correct octane, I prefer 116 for safety. I wouldn't adjust anything on the car until you've read just about everything on this site, especially the tuning portions. If tuned correctly, you can run a lot of boost on a stock engine, but even a strip terror built motor won't last at low boost if not tuned correctly. Another thing to note, and I'm sure some one will chime in about this if I screw it up, the stock turbo and intercooler setup does have some limits as far as efficiency goes. With the right tune you could put 30psi through them but the stock turbo will be heating up the air a very large amount, and the stock intercooler can only pull out so much heat. So if you go too high, you're just hurting performance. I've been told that about 21-22psi is about as high as you want to go with a stock intercooler. If I'm incorrect I hope someone straightens me out.
