I bought a Borg Warner/IHI GM-8 (from a 6.2 L diesel) remanufactured, no shaft play. Compressor A/R is 0.76 w/ a flow rate of 42lbs./min, compressor map is suppose to be close to a T3 super 60 trim; turbine A/R is 0.78. This turbo is suppose to have a max boost of 30 psi. How do you think it will match a VQ35de? Thank you for your inputs.

 

Very very small. Not well matched for the engine at all. BorG Warner turbos are top shelf though, but not a good size for your engine at all.

 

i never understood this. Why buy the turbo then ask us if its good for you? It should b the opposite way. Don't mean to be an @ss but hope u understand where i'm coming from.

.70 compressor sounds ideal for the maxima and that turbine isnt too bad as long as the turbo is big but if its supposed to be similar to a T3, its kind of small.

 

U h Oh.

 

It pays to do extensive research before buying absolutely anything.

 

Its just that when I asked I was told it was a "Borg Warner T3/T4 remanufactured using Garrett internals" but when I got the turbo the spec that is stamped on the turbo was GM-8 SPO; so I called Borg Warner, gave them the spec and their tech. advisor told me the A/Rs.

 

I just did some looking, I don't know where they came up with the fact that 42lb/min is close to a super 60 but its not. Super 60 maxes out at about 35lb/min, its closer to a 46 trim t4. Anyways it's still small for a VQ35. The turbine side is up in the air though, .78 A/R doesn't mean anything without a comparative value. A/R is just a ratio, and without knowing the turbine style it's hard to judge how good or bad it is. It could be like a .78 A/R t25 which is tiny, or a .78 A/R T4 which is much better suited for a vq35.

 

Just follow and post on my thread http://forums.maxima.org/showthread.php?t=451283

 

if your going to spend the money for a turbo setup, just spend the extra money, on a proper sized turbo.

 

Here's some pics of the turbo:

 

Keep in mind that you will want a different sized turbo for drag racing or top speed racing (larger) than you would for a street car or an autocross car (smaller).

So, though this turbo my be small for all out power it may (and probably will) be great for a street car with realistic power goals.

Turbo retailers love to sell customers 800 hp turbos for 400hp cars. Don't believe everything you read.

allen

 

On the other hand if push 400hp worth of air through a turbo that only supports 400hp, you are operating way out of the optimal efficiency range of the turbo, creating more heat than you would if you had a more appropriately sized turbo.

 

To me that turbo belongs on a 4 cylinder not a 3.5L six cylinder. I have used a Turbonetics T70 turbo and just recently put on a Switzer T04E T4 with .70A/R compressor and .96A/R exhaust and both have been just the right size for my application but mine is on a VQ30 not a 3.5L. You could of got a T70 and put out quite a bit of Hp without much lag but it all depends what you want.

 

how does that turbo manage to do well on a 6l truck but not a 3.5l car

 

Because it is being used for a whole different concept. Diesels use turbos to create torque to haul heavy loads or to pull heavy objects. Diesel engines and gasoline engine are quite different. Compression is alot different and fuel systems are different compared to a VQ engine. When finding a turbo for a car you do not want to go to big where your car will not be able to push it and there is alot of lag and not enough fuel to keep up with the forced air but then again you do not want to go to small where you are going to max it out. There is alot of research that you should do when finding the right turbo for your car and what A/R's you want to have which alot of people do not do. I am a Diesel Mechanic for the U.S Navy and work around heavy equipment and turboed diesels everyday and I have learned alot in the years I have been doing this and thats why I browse through these forums to help some ?'s that some may have and because I own a turboed maxima myself and have been in the same situation as alot of the members are going through. Yes that turbo will work but you have to ask yourself what are you putting on the car for, do get alot of horsepower right, so you are going to want to find a turbo that will support quite a bit of horsepower but not be overkill. It will work but I and I believe some others will agree with me that it was not the best choice for his car.

 

Actually, running 400hp on a turbo that is rated for 400 hp should not be out of it's efficiency at all. 500 hp would be though. But I know exactly what your getting at!

allen

 

I'm not talking about being off the map, but you would certainly be out of the highest efficiency islands on the map. You would be at the extreme right of the map, whereas the peak efficiency is in the center of the map.

 

So how do you think will my powerband be w/ this turbo?

 

It would be shifted towards the midrange somewhat, lacking in high rpm power but having more midrange torque.

 

as a supplement to what t70max said, the diesel has a smaller turbo due to lower RPM. if it had a monster turbo it would spend its whole powerband spooling up and never hit the real output.

 

Definitly more midrange and no lag but your car will be quicker not insane spinning through 2nd and 3rd like some of the other turboed max's. Do you already have all your piping for the turbo? There is alot more to turboing a maxima then just finding a turbo and wanting to put it on. You need to change fuel components,exhaust,axles,motor mounts,ect. Just know what you are getting yourself into before you start this project. I have gone through 2 transmissions in mine and a N/A maxima is alot more reliable if you are going to be driving it everyday unless you know your stuff. Mine is actually very reliable now but took some time to get there.

 

Thank you for all your responses guys; I got a 255 lph walbro, and soon to buy superdave's 440 or 555 cc injectors; I already have a SAFC 2 and an R500 wideband installed in my car; we're gonna start cutting and welding all the piping after I install the fuel pump and the injectors; I have front and back MM inserts and a torque engine damper(custom); are there already aftermarket axles for 2002-up altima/maxima?

 

I wouldn't consider buying new axles unless you break them. Some high Hp Maximas are still running stock axles, while others I know go through them like changing oil. www.raxles.com is a good place.