[nicktyler]

How much lag should my 335i have if I was to floor it in 2nd at 20mph?

[B005T3D-G]

About a second then it should start pulling hard

[dxb335d]

In first or second?

[nicktyler]

I'm pretty sure mine is OK then. There is definatly lag but not much over a second. Also it seems to come in 2 waves a bit of lag then a short build and then a huge pull. I thought that was the twin turbo thing. Is that right?

I have some problems mentioned in another thread and I'm trying to figure out if I have alot of lag due to carbon build up or something. If I do the same thing from higher in the rev range it feels very low on boost. Maybe it's the actuators? I think I have read too much and am confused and paranoid now.

I only have 1 month warranty left. Why can't it just break rather than playing silly buggers, not throwing codes and "apparently" behaving perfectly for any mechanic?

[nicktyler]

Originally Posted by dxb335d

In first or second?

In second about 2krpm. Whats weird is if I did it in first from 20 I would sometimes get what feels like no boost. Just the same as 2nd from 35-40mph. But only sometimes. If I pull from lower down rpm and leave foot down it is fine.

I was thinking if there was alot of lag and I thought it was normal it could be a nother symptom of what is going on here:

http://www.e90post.com/forums/showthread.php?t=654232

[Subzero2003]

Mine there is about 0.5seconds lag and it goes, then about another 0.5 seconds later it GOES

[doughboy]

OP

This is where a boost guage is very useful, I take it you don't have a JB4? If you did you could put boost on your fuel gauge, its brilliant!

You can see exactly how the boost responds to your right foot. You'll see how it picks up, either smoothly or otherwise, you can see steps or overboost too.

Flooring it from a no boost or overrun condition is always the worst case and really shows the lag, I avoid it like the plague as it just reminds me how I hate lag.

You only need to tickle the throttle before you accelerate, blip on change down is best IMO, then its ready to go BAM! no lag at all.

The boost guage really shows how fast and accurate the boost targeting is, it just flicks from zero to say 10psi with a little tickle of throttle, then you're ready for off - lag free!

[nicktyler]

I had it in my last car and I do miss having a boost gague. It would make my life alot easier deciding weather the lack of power is a lack of boost. Is there any way of getting it out the OBDII and on to a laptop screen or anything? I suppose the maf would give an indication of low boost as well?

[doughboy]

The N54 has no MAF. It runs an unmetered intake.

You could buy a cheap boost guage from halfords? Just lash it up to use for testing.

[nicktyler]

That is an idea. Would any boost gague work and just need to be wired in? I had Defi before but it was certainly not cheap.

It's just the fitting I am not too confident with. How long do you think it takes?

[doughboy]

You want a simple mechanical analogue gauge that runs directly on a thin rubber hose from the connection point under the bonnet, no wiring etc as its not electrical - it measures REAL boost.

The best place to pick up manifold boost/vacuum is on the divertor valve vacuum lines, just buy a 'T' coupler and add in the line to the boost gauge.

Hardest part would be getting the line into the passenger compartment, as its temporary you could just run it out under the back end of the bonnet, by the wipers, and then in through a slightly open window.

Halfords do one for £30, but you could probably get one of ebay for less. http://www.halfords.com/webapp/wcs/s...ource=shopping

It has an option to wire up for backlighting, but you don't need to use that.

You can get a pod for it too and go the whole Max power thing! http://www.halfords.com/webapp/wcs/s...k&iozone=PDPz1

[phil200tdi]

Just buy a jb4, it overcomes all your problems!

More boost!
Anti lag feature
Boost gauge in dash
Code reading

For £300 you can't beat it..

[nicktyler]

I have considered buying the JB4 but I spent £500 on the Evolve-R tune allready. Is JB4 really that easy to install?

I will get the car diagnosed and fixed before changing the tune as I'm pretty sure that is not the problem.

[phil200tdi]

I didn't realise you had evolve-r cable sorry. Don't want to start a tuner war!!

Jb4 is an easy install though. I just added meth integration to mine on the weekend!

[doughboy]

Originally Posted by phil200tdi

I just added meth integration to mine on the weekend!

.......and? review please Phil!

[AlanYoro35i]

I think my cobb ap also shows boost when connected up.. if your talking about easy install then jb4 is nowwhere near EASY! I wanted to buy jb4 but you need to dismantle the ecu and connect It all up.. I'm afraid I will bugger up a few pins like building a pc..

Anyway since you have evolved map then you should feel abit more lag sincethe turbo pressure has been risen up?

[michaelalex17]

ok what you are experiencing doesnt seem like is being answered. if you car is an auto then i think i know why its doing this. i believe you must shift out of first at around 30mph. so when you are going 20mph in 2nd and floor it, it downshifts to first and then you get the power. that the lag you are talking about. trying going 20mph in first and i guarantee there wont be any lag.

[nicktyler]

Originally Posted by michaelalex17

ok what you are experiencing doesnt seem like is being answered. if you car is an auto then i think i know why its doing this. i believe you must shift out of first at around 30mph. so when you are going 20mph in 2nd and floor it, it downshifts to first and then you get the power. that the lag you are talking about. trying going 20mph in first and i guarantee there wont be any lag.

It's a manual. I just thought if there was too much lag it could be a symptom and help to explain my other problems. Which include (but def not limited to) doing as you suggest in 1st I would get no boost at all sometimes and then other times it works fine.

[michaelalex17]

Originally Posted by nicktyler

It's a manual. I just thought if there was too much lag it could be a symptom and help to explain my other problems. Which include (but def not limited to) doing as you suggest in 1st I would get no boost at all sometimes and then other times it works fine.

well if you dont have a tune then your max boost will be around 9psi. when you passt 6,000 rps then your boost goes down. and by 7,000 rpms your boost is at around 4psi. so if you downshift to around 5,000rpms you will have a lottt of power but over that you will feel no power. if you get a tune then it will allow your boost past 6,000 rpms to be raised and you will feel more power higher in the rev band. i hope that helps

[phil200tdi]

boot it in 1st or 2nd at 20mph on anything but a dry road i'd get DTC coming on to stop the fun.

[B005T3D-G]

Originally Posted by phil200tdi

boot it in 1st or 2nd at 20mph on anything but a dry road i'd get DTC coming on to stop the fun.

Switch it off then

[phil200tdi]

Originally Posted by doughboy

.......and? review please Phil!

Working on it.

I was gonna do some dynolycious runs but then the windscreen washer light came on - low on meth after 3 days, oops..

Suffice it to say its mental. I'm truly stunned by how quick it is according to the butt dyno. Torque especially is huge, like another turbo coming in. All very smooth and seamless too..

Once I've filled up with meth I'll do some power runs and post up the times. Suspect 0-100 in between 9-10secs.