GN/T-Type Turbo For Jeep 4.0l
 

Ive been searching here and on google and cant find much information on this turbo and im trying to decide if its the right size for my 4.0 jeep i6. the turbo was givin to me and im told is the stock turbo from an 87 t-type regal. i would gladly do my own calculations if i could find a compressor map for this crazy thing. lol. Im hoping to run around 5-6 psi and start boosting at as low an rpm as possible. if i missed something in my searching just show me where to go and ill do my own reading and whatnot or if you just have a straight answer for me thats cool too.

So no one has anything to say about this?????

I would say that it's probably a good turbo for just 5-6 psi. The v-6 in the regal was smaller than the 4.0 so you can spool it really easy.

Thanks for the reply . i found a compressor map and was playing calc that plots a graph on it but im not sure if im doing it right. here is the map i got
http://www.***************/turbocalc...product_id=187

well it seems that didnt work. why did it block the name of the website?

Can you email that to me at david.whitney@aviano.af.mil.

email sent. The part im most confused about is how do i know the ve of the engine at a given rpm and also how do i know when the turbo will start to spool and when i will hit max boost?

It's hard to say on the spool time but most articles will tell you to use 80% VE. Try this site Turbocharger Compressor Calculations

with the info you gave me im showing air temp to be around 170 on a 90 degree day and my plotted line goes straight up the middle of the map until max boost at which point it goes straight over and hits the choke line right after max power ( based on n/a max power im assuming) does this mean the turbo is actually to small?

I"m sure it's not the ideal turbo for your engine but when your trying to build a budget system you might have to sacrifice a little here and there.

A Grand National engine is a 3.8 litre V6 and uses a 1800 stall torque converter with the A/R of .63 on the exhaust housing. Its spools up damn near quick with factory setup. If you were to brake torque a stock GN with the 1800 stall coverter you can make6-10 boost just standing on foot brake. With the 4.0 motor it will be easier to spool up. If you are only lookig to make 6-8 psi you should be just fine. What stall is your converter? if its just around 1000 rpm stall then it might be a little slow to spool up just off the line but when you're rolling around 20 mph or so it will spool up ok. Also use a good size wastegate to control the boost down to 6-7 pounds.

HTH
Prasad

Thanks for the info. My jeep is a 5 speed so no converter stall issue to worry about. Any insight on my plotted line on the compressor map? (About 3 post back)

I can't see anything, can you sent me a link to wikedv6@hotmail.com.

Thanks
Prasad