Hello. I'm currently pondering a plan to upgrade soon in the future to possibly a bigger turbo. Currently my mods are as far as performance are:

MAP EF2 turbo
1000cc ID injectors
DW65 fuel pump
AEM intake
ETS intercooler and pipes
Grimspeed EBCS
AMS downpip
Perrin catback

tuned by CBRD via Cobb accessport. I'd like something that minimizes lag and can be safely ran with stock block. I currently have 70000 miles on the engine but last I had a compression check, everything was fine.

 

That's a bit of a pickle because bigger turbo= bigger lag. Plus anything bigger and you're really starting to push the limits of the block. How about an MHI-18k? Or maybe CBRD's Twin Scroll RBX kit.

 

You need to quanrify what you would consider laggy. I'm happy with a setup that comes on in the 4-4500rpm range, like a good turbo kit (ETS, AMS, STM) with a Precision 5858 or Gen2 5558 would. Especially because it will make really good power on pump gas (500ish) and E85 (600ish). All while actually being easier on the engine than any stock frame turbo due to reduced back pressure and heat.

 

Turbo kit is probably best option if cost was not an issue.
But with your current set up you could probably Just do a turbo upgrade to a FP Red or GTX 3576r and manifold , E85 if you have access to it. Proven set ups with those 2 turbos with great results.

 

I was thinking of moving a way from stock frame turbos and maybe looking at a turbo kit such as the ones CBRD offer. Looking for reliability as well since I dont really want to build the motor.

 

I only hear great things about the CBRD kit - kinda wish i went that route if I was to start from the beginning again. 'No ragrets' though

 

I would stay away from EFR turbo's. They don't make the best power per pound of boost, and they make a lot of back pressure. The precision 5858 is a proven great option on the X, the gen2 5558 should aslo be even better. Pair them to a Vband hot parts kit and make awesome power.

 

Would the CBRD RBX twins roll turbo kit be a nice, worthwhile upgrade from a MAP EF2?

 

I second this. With a great tuner, the MHI 18K and BorgWarner 7163 are both the perfect mates for a stock block.

Since you would like to move away from stock frame turbos, BorgWarner 7163 twin-scroll setup (like the kit from CBRD) would be the way to go. And yes, in my opinion, it's definitely worth the upgrade for you.

 

What are your horsepower goals? Hard to recommend a turbo without knowing your goals.

 

His goal is an upgraded turbo on the stock block. He wants the fastest spooling turbo:

 

He already has an upgraded turbo and you also didn't answer my question.

 

400 to 450 would be nice. Want to be reliable as my motor is still stock and don't plan on building it for a while. I have a MAP EF2. Just wondering if the CBRD twins roll rbx be a worthwhile upgrade.

 

Following for a friend, who has the same inquire for not completely rebuilding but maxing out the stock block on his X.

 

EF2 would hit those goals on E85 no problem.

If you want to keep things simple but still want a larger horsepower potential turbo, look into Garrett GTX3017R or GTX3076R Gen 2 bolt on.