R-Spec mbc

**AlanG** · Monday 6th April 2009, 16:00

Has anyone fitted one of these and if so what did you think. Worried it's too good to be true as my car is now a rocket. My worry is that I have it screwed all the way down. Your thoughts please??

**t5 pete** · Monday 6th April 2009, 16:02

I think another new member has just fitted one of these and was happy with it do you happen to have a psi/bar boost gauge fitted to tell you how much pressure you are producing

**AlanG** · Monday 6th April 2009, 16:08

I don't and I also know that I should. Don't want to ruin my car interior with add-ons. Thinking of backing the mbc off as it is ridiculously fast.

**p fandango** · Monday 6th April 2009, 16:16

Originally Posted by AlanG

I don't and I also know that I should. Don't want to ruin my car interior with add-ons. Thinking of backing the mbc off as it is ridiculously fast.

altho its not an accurate measurement, the end of the white section on the factory gauge is normally around 15psi

**AlanG** · Monday 6th April 2009, 16:19

Is that deemed safe? Just feels scary fast.

**p fandango** · Monday 6th April 2009, 16:23

Originally Posted by AlanG

Is that deemed safe? Just feels scary fast.

13psi is normally considered a safe limit, but how much safety margin there is in that i've no idea

an MBC really does transform the car & alot more aggressive than a remap, which is why i love um

**t5 pete** · Monday 6th April 2009, 16:34

for the price of a boost gauge i would just buy one with the piping and connect it just to see hwat pressure you are producing or even better if some you know has got one just borrow that from them while you cheack the pressure.
Ive just seen this one and for £14 delivered to your door and a couple of quid vacume pipe IMHO it worth buying one just to cheack.
Better safe that sorry i have a remap and boost to 16psi with the fuel cut lifted i would say 14psi is a good level of pressure.

http://cgi.ebay.co.uk/Meter-Gauge-BO...1%7C240%3A1318

**PaulZX** · Monday 6th April 2009, 16:38

I run at 12psi, and don't play with the mbc...

for now....

**callyuk** · Monday 6th April 2009, 22:09

i have an R-Spec mbc and its been great although im worried that yours is all the way wound in as mine is know where near that still has around 8-9 threads showing and set at that its boosting to 1 bar about 15psi with it all the way wound in i find it hard to belive that you are not hitting the fuel cut.
just a question are you sure you have it plumbed in correctly

**Big Pete** · Monday 6th April 2009, 22:33

I have HLM 304 re-map and in 3rd gear it goes past the white part on the OEM boost gauge, and so is around 16psi on my aftermarket boost meter.

**polredt5** · Tuesday 7th April 2009, 09:04

i had one of them on my t5 and it was giving to much boost no matter how i adjusted it!I ended up taking the ballbearing out of it in the end.Paul..

**AlanG** · Tuesday 7th April 2009, 14:15

Originally Posted by callyuk

i have an R-Spec mbc and its been great although im worried that yours is all the way wound in as mine is know where near that still has around 8-9 threads showing and set at that its boosting to 1 bar about 15psi with it all the way wound in i find it hard to belive that you are not hitting the fuel cut.
just a question are you sure you have it plumbed in correctly

It's definitely plumbed in correctly. Not sure what to think as it's running beautifully and very powerful. Going easy,it'll do over 30mpg. Hmmm...

**JelT5** · Tuesday 7th April 2009, 14:27

Originally Posted by p fandango

an MBC really does transform the car & alot more aggressive than a remap, which is why i love um

Me too...still grinning mate!!

**AlanG** · Tuesday 7th April 2009, 14:40

Still a bit concerned though. Seems too good to be true.

**t5 pete** · Tuesday 7th April 2009, 14:43

Originally Posted by t5 pete

for the price of a boost gauge i would just buy one with the piping and connect it just to see hwat pressure you are producing or even better if some you know has got one just borrow that from them while you cheack the pressure.
Ive just seen this one and for £14 delivered to your door and a couple of quid vacume pipe IMHO it worth buying one just to cheack.
Better safe that sorry i have a remap and boost to 16psi with the fuel cut lifted i would say 14psi is a good level of pressure.

http://cgi.ebay.co.uk/Meter-Gauge-BO...1%7C240%3A1318

As i have said before you dont need to fit the gauge just use it to find out what pressure your using and if something does go wrong imho you will fell pretty stupid for the sake of £14 that could have showed problems

**Mrsmopp** · Tuesday 7th April 2009, 14:52

A cheap bost gauge wont necessarily be any more acurate than the less than acurate standard gauge - to be sure you will need to spend a few quid on a decent gauge plumb it in, take it for a test drive and then take it off again.

Personally I think you are playing with fire, you already have a remap which should boost to around 1bar which is already verging on pushing it (do you have any idea on the afr??) plus you have wound your MBC right open without checking where pressure its allowing - its it worth it for some tyre shredding?

**t5 pete** · Tuesday 7th April 2009, 15:03

I would say any boost gauge would be more accurate than the standard gauge in the car.
To be able to get a really accutate boost gauge you will be talking serious money and i doubt hes willing to spend that, as he is not wanting to shed out a couple of quid for a cheeper one.
If he allows 1-2 psi either way he will have a good enough estimate of what the car is producing.
Theres another way around this and that is to book the car for a rolling road where he can get the afr's cheacked aswell and that will cost around £50.
If i was in this situation i would want to find things out rather than keeping them in the dark.
pete

**AlanG** · Tuesday 7th April 2009, 15:22

Think I'll back it off some. Don't want to break anything. Thanks to all for your thoughts/comments

**AlanG** · Monday 11th May 2009, 21:11

Well one month on,the old bus is still flying. No oil consumption,30mpg and running perfectly. The re-map is working well and the mbc adjusted to take the dash guage a couple of mm beyond the white. Done a 1000 miles or so and no problems. Running 95RON. Happy days...

**AndysR** · Monday 11th May 2009, 21:22

I would seriously look into getting the boost and fuel levels checked. From your description it sounds like your running 304 boost levels on a 280 remap when the 304 is designed for 97 ron fuel only and as it really can be the end of the engine if either aren't correct. Plus oil consumption is not a test of whether the boost/afr's are correct.

The best thing you can do is ditch the 280 and run the 304 with 97 ron fuel if you want the car to go faster as budget performance isn't usually budget for long

Not a dig as I am pleased you are happy with your car it's just my 2p's worth