I have 2003 evo 8 with still stock engine internal. I installed a atp 3071r .63ar kit. I think it can start to kick in low rpm. what is the safe boost pressure and what is the safe minimum rpm for full boost? I dont want to bend my rods soon.

 

Get the car tuned the tuner will determine a safe boost level. Biggest thing on the stock bottom end is to keep the tq down an bit for rods sake

 

i am my own tuner. i had few strong car. i maped them all with good result, but i am new in evo world.

 

Most will want to hit their target boost pressure as early as possible for best spool. And that RPM on a street car is never low enough!

 

Get rid of the ATP kit and install an FP Green or FP Red. Everyone will be much happier with the end result. Do a search for ATP and ATP 3071 kits. In my experience the 3071 is a complete waste of time on an Evo - no matter which kit it's on.

l8r)

 

yes, i know, but low rpm boost(torque) can kill rods.

 

i searched and read a lot. there is few nice thread about this, but i used gt3071r on other 2.0 turbo application. it was fine. Why can be that bad on evo? there was a lot of usefull info. its will be nice, i hope.

 

the 3071 is a little bigger than the stock turbo, so minimum rpm level for max boost shouldn't be a problem. I've seen these turbo's been used to good success (300kwatw, 400whp) on different 2.0ltr engines.

dont be discouraged by "the americans". What i've noticed is that generally the evo engine takes alot of boost to make good power. The combustion chamber is good for high torque, but no so much for top end power. Obviously you can chuck on a monster turbo and feed it 45psi and make 750whp.

alot of people take the stock engines to 500whp etc. but alot of people say 400ft/lb wheel torque is about the limit on stock rods/rod bolts.

In My Opinion if it's tuned properly, and the engine is in good condition, you'll have a hard time killing the engine with that sized turbo.

Good Luck

 

agree with the limit torque at typical peak torque rpm's
you could achieve that by limiting boost or timing

 

I had a 3071 .63ar on my car. It was mated to an AMS exhaust manifold. Spoolup was mediocre, as was power. Spoolup on the ATP kits was notoriously poor, so I can't see that performing any better than what I had. To make matters worse, the 3071 also surged (read: car shaking compressor surge) in 5th gear between 3000 and 3500 RPM. I ended up swapping it out for a 50 trim, lost almost no spoolup and gained a whole lot of power ... and no surging issues.

This is all "old tech" these days, though. With the advent of the stock framed FP turbos, there is absolutely no reason to go with a T3/T4 turbo on an Evo VIII/IX unless you're looking to go with something like an HTA 35R or bigger. An FP Green will dominate a 3071 in all categories; an FP Red will crush it. IMO even my 50 trim is obsolete. Although at 408wtq/480whp it is still a hella lot of fun.

l8r)

 

I am running the AMS 30R(same specs as urs) and I run 27LBS of boost, but as was mentioned by gsrboi80 u need a good tune and that will make ur discision for u.

 

i tuned few engines with smaller hotside turbos. if you try to map your car right under the surge line on 2nd, 3rd and 4th gear, you will have some surge on 5th gear if you push full throt on low rpm. but why do you have to push wot on 3000rpm on 5th gear? that is normal. i allways care about, what is going on inside my engine.

i only want to use this stock engine until the winter. i have stroker parts, but i dont want to be without evo in the summertime.

 

Cruising on the interstate and not wanting to downshift into 4th, that's why... and to me compressor surge is not normal, it is unacceptable. When I modify my car, I want it to perform at least as well as it did when I drove it off the dealer lot. Anything less reeks of backyard "engineering" and is summarily removed from my car. I understand not everybody is a perfectionist, so if surge is acceptable to you, then go right ahead.

l8r)

 

i think i was not clear. all turbos has surge line, as you know. i meant, if your car maped close to the surge line on 3rd gear, its will surge if your push wot at 5th gear on 3000rpm with this small turbine housing. i did not say, surging is good or normal, but if you use your car, like a guy, who are uderstand his car you can manage it. if not, your car has to be map near from surge line, its no way for surge.(like you bought at the dealer).
dont think i am a crappy 18years old baseball hat guy.

 

Turbo is just spooling faster than the engine can consume the air - big cams and a good tune have always helped me overcome this with small hot side turbos... If the ATP kit spools slower it will also help a bit.

Depending on the boost controller you have you can also make the turbo spool less aggressively.

If you already have the ATP turbo on your car just try to limit the peak torque and stay under 1.5bar boost with at least a 100RON fuel and you should be fine, Water Alky injection is a must on the stock block...

.