Turbo Lag from Piggyback or Flash?

[WhereItsAt]

A thread that was previously locked had a couple posts concerning lag from adding the PROcede. I thought it was best to clear this up. It seems that many people are new to turbo cars and confused to what the electronic mods to. Below you can clearly see the power curves of a car (stock than PROcede). There doesn't appear to be any lag - just gobs of power. This was taken from an e90post thread - http://www.e90post.com/forums/showth...=V2+Dyno+stock

Thought I would share.

[Evolved]

In the other thread I said all that was needed was a dyno graph or a boost plot to show if there was lag or not. Thanks for that.

[mikeo]

Gobs of power is right! Aren't turbos wonderful?

[WhereItsAt]

No doubt, this engine is wonderful. Everyday I jump from one side of the fence (buy the 335 or 135) to the other (cheap, money grubbing Bastard!).

[WAY]

But stock is substantially better than Procede up to 2500rpm, which could account for a lot of start and stop city driving. Other ECU reflash like the one on my GTI has better power and torque almost all the way from 1300rpm from memory.

[larryn]

In that other closed thread, I had mentioned a few times that there was a definite, perceptible lag form when you hit the accelerator to when you get power on an autocross course...

I just read a new thread on e90post that backs that up:

People probably notice that sometimes when you hit the throttle there is quite a bit of hesitation. I’m not saying it eliminated turbo lag, I’m talking about that second or so where you pretty much stand still after hitting the throttle. This is especially noticeable if you’re hitting the throttle from higher RPMs. This applies to both off to on throttle and from cruising part throttle. If you’re going on-off-on for some reason it’s amplified even more (see below).

This is exactly what I experienced on the tuned 335's that I've driven.

It seems that this new aftermarket diverter valve removes a lot of that initial hesitation.

I did NOT post this to open the proverbial can 'o worms, but to state that the tunes that I drove (v1.47 and v2) did have that feeling of lag, backed by dyno or not. :smile:

[mikeo]

I doubt a chasis dyno would show the issue you have experienced, Larry. Chasis dynos aren't great duplicators of the real-world. Is that the Forge diverter valve?

So what, exactly, do we think is happening to cause that significant hesitation with chipped cars vs. stock in an on-off-on throttle sequence?

[larryn]

Yes it is. I may wind up getting one, if we see a few more posts like that one... It's relatively cheap too, at ~$335. I wonder if the one for our cars will cost ~$135.

[ARES45]

How much?

[mikeo]

Here is and interesting review of the Forge DV by O-cha.

[larryn]

Originally Posted by mikeo

Here is and interesting review of the Forge DV by O-cha.

That's a cut-n-paste review from the review he posted at e90post, that I linked to (above). I guess he liked it... :smile:

[ARES45]

What does it take to install?

[larryn]

Not sure. The area where this goes is quite a bit tighter on the 135i, than the 335i. On the 335i I've read it is about an hour to install. I'd expect it to take a good bit longer on the 135i, unless you can train your 3 month old kid with tiny hands to do it for you.

[ARES45]

So I will need to get a circus monkey, dang those are hard to come by.

[mikeo]

Sorry for the double link, Larry.

I read some manufactruer's installation instructions for their piggy-back chip where they said that while the 335 install can be done completely from the top, the 135 requires removal of the under-pan and then install is performed from underneath the car. They mentioned that after taking 5-minutes to remove the under-pan the install was actually easier on the 135 working from the bottom (if you have a lift, anyway).

I suspect we'll be under the car doing work more than 335 owners.

[larryn]

Originally Posted by ARES45

So I will need to get a circus monkey, dang those are hard to come by.

[larryn]

Originally Posted by mikeo

I suspect we'll be under the car doing work more than 335 owners.

Very true! The SSTT mod on the 135i requires you to get under the car, but it's still the simplest installing tune (other than the Dinan, which you simply drive up and have them reflash your car).

With the Dinan, if you don't have the oil cooler, they will install one for you (since they require it), for another $2000...

[mikeo]

Remember the days when the 1955 Chevy V-8 looked small in the engine compartment? Nowadays you either have to own that trained monkey or be multi-double-jointed.

[mikeo]

Originally Posted by larryn

Very true! The SSTT mod on the 135i requires you to get under the car, but it's still the simplest installing tune (other than the Dinan, which you simply drive up and have them reflash your car).

With the Dinan, if you don't have the oil cooler, they will install one for you (since they require it), for another $2000...

Lets see, $2000 + $2000 + Labor + Tax = INSANE.

I'm still considering the Dinan flash, but only if our 135s have the factory oil cooler.

[larryn]

Originally Posted by mikeo

Lets see, $2000 + $2000 + Labor + Tax = INSANE.

I'm still considering the Dinan flash, but only if our 135s have the factory oil cooler.

Don't forget their $1600 intercooler upgrade while you're there... :biggrin: Totally worth it, if you want the Dinan badge on the back. :wink:

[mikeo]

Dinan should just sell us all their aftermarket 135 parts then just throw the car in as a freebie.

Don't misunderstand, I've bought many Dinan parts and think they are top quality stuff. But I thought the Stage 5 software for my E36 M3 was expensive at $900.

[atr_hugo]

Here's a writeup of the valve on the Forge site:
http://www.forgemotorsport.co.uk/con...oduct=FMDVBM35

And here's the text stolen from the Forge site:

Developed specifically for BMW’s all-new N54 twin turbo motor, as found in the BMW 135,335 and 535 models, Forge Motorsport adds another replacement valve application to our already extensive vehicle specific and universal valve lineup. While virtually identical in operation to the Bosch style valves as used from the factory on many other turbocharged applications, primarily Volkswagen and Audi, BMW has utilized a very different type of valve connection mechanism that makes their product and our replacement components very unique. Starting with the world’s best selling direct replacement Bosch style valve, our own 007P piston-based design, we have revised virtually every single component of the valve body, (except the internal piston), in order to retain BMW’s unique connection mechanism yet offer improved functionality in every other possible way. The entire valve assembly is precision CNC machined from T6-6061 billet aluminum alloy on our very own Mazak CNC milling machines. Again, the valve is an aluminum piston based design, offering significantly improved reliability over the failure prone OEM diaphragm valves, yet with no change to valve response time. We utilize ultra high temperature Viton brand silicone o-rings for sealing and Mobil1 fully synthetic bearing grease for lubrication. The valves are fully tunable for both boost holding capacity and response by way of proprietary interchangeable springs and shims (washers to marginally adjust preload). By utilizing this method of valve tuning with multiple custom spring rates, the valves will retain the maximum range of piston travel and flow volume regardless of which spring rate is used. Valves with a singular spring requiring that adjustments be made by continually adding preload will suffer from decreased piston or diaphragm travel as the spring tension is increased. Though these types of valves may hold high boost levels under load, they will actually suffer from limited flow volume at throttle lift when the valve vents. The hoses included in the kit are a custom made multi-layer fabric reinforced flexible silicone hose that are designed to allow compatibility with the stock airbox and charge piping setup without any permanent modification being required to adapt our replacement valves. Even the included hose clamps are overkill. They are specifically designed for use with silicone hoses, utilizing a beveled band edge and a pressed in drive mechanism rather than perforated. They are even approved by NATO for international military use. All told, this direct replacement valve kit will be suitable for a bone stock car to one that is heavily modified. They can be installed on the car right on the showroom floor and they will last well past having upgraded your intake, exhaust, and ECU software. They are capable of handling an infinitely wider range of boost pressure, more reliably, than the OEM valves, and they carry an unlimited lifetime warranty and money back guarantee.