[Slidewayz]

Hi,

I have come to the 335i after owning an RX-8 with an 18g GReddy turbo. I've got the latest, greatest PROcede Stage 0 map on the 335i.

In comparison, the 335i seems pretty laggy...with a turbo rotary the boost comes on like a BANG if you're running a small turbo.

Once the boost really comes on, the 335i is an absolute hoot!

OK, so here's my question: Is the 335i's gradual boost a stylistic decision by the tuner, or do I just need to get used to the gradual spool?

[vase330]

Get the latest BMW Software installed if you have lag. V32.1 fixed lag for me. But with a Tune like PROCede, you should not get any lag. You sure you are feeling lag? If your RX-8 the boost came on like BANG, wouldn't the RX-8 be the one that lagged then just dumped the boost on? Seems you have this backwards

[OpenFlash]

Originally Posted by Slidewayz

Hi,

I have come to the 335i after owning an RX-8 with an 18g GReddy turbo. I've got the latest, greatest PROcede Stage 0 map on the 335i.

In comparison, the 335i seems pretty laggy...with a turbo rotary the boost comes on like a BANG if you're running a small turbo.

Once the boost really comes on, the 335i is an absolute hoot!

OK, so here's my question: Is the 335i's gradual boost a stylistic decision by the tuner, or do I just need to get used to the gradual spool?

By most turbo engine standards, your v3'd BMW is going to be about as lagless as you are going to get.

Your RX-8 was even more responsive because it used a pretty miserable undersized turbo that could only support 5-6psi up top. Typical of most low-boost aftermarket turbo kits. It made for whiz-bang response but at the expense of top end power. The other advantage is that rotaries have extremely strong exhaust pulses since they have big exhaust ports (not valves).

Shiv

[Slidewayz]

Originally Posted by shiv@vishnu

By most turbo engine standards, your v3'd BMW is going to be about as lagless as you are going to get.

Your RX-8 was even more responsive because it used a pretty miserable undersized turbo that could only support 5-6psi up top. Typical of most low-boost aftermarket turbo kits. It made for whiz-bang response but at the expense of top end power. The other advantage is that rotaries have extremely strong exhaust pulses since they have big exhaust ports (not valves).

Shiv

Shiv, it was more like 2-3 psi up top! Undersized is a far too gentle assessment...that little 18g was running so far outside it's efficiency range it was ridiculous.

So, it's all relative? Will a less restrictive intake and/or exhaust help spool time? Also, I guess the gt28r upgrade will also help spool time for the lucky b*astards that can do it?

[OpenFlash]

Originally Posted by Slidewayz

Shiv, it was more like 2-3 psi up top! Undersized is a far too gentle assessment...that little 18g was running so far outside it's efficiency range it was ridiculous.

So, it's all relative? Will a less restrictive intake and/or exhaust help spool time? Also, I guess the gt28r upgrade will also help spool time for the lucky b*astards that can do it?

Oh that's right. That 18G was even more awful that I remembered. You would never see anything so poorly sized in a modern turbo car. The stock turbos on the n54 are so well matched to the engine that I don't think we are ever going to find something less laggy without sacrificing hp potential. The fact that these cars can make 10psi by just 2200rpm and still make nearly 400whp on pump gas is just outrageous. I don't think any GT28r upgrade will be as responsive. But they should make silly power

Shiv

[Slidewayz]

Originally Posted by shiv@vishnu

Oh that's right. That 18G was even more awful that I remembered. You would never see anything so poorly sized in a modern turbo car. The stock turbos on the n54 are so well matched to the engine that I don't think we are ever going to find something less laggy without sacrificing hp potential. The fact that these cars can make 10psi by just 2200rpm and still make nearly 400whp on pump gas is just outrageous. I don't think any GT28r upgrade will be as responsive. But they should make silly power

Shiv

Yeah, at redline that 18g sounded like it had Parkinson's!

You don't think ball-bearing vs journal bearing would help?

How 'bout intake/exhaust?