detonation or rev limiter

[st5ve]

My 855 T5 project is going very well, the car is now on the road (although the project is far from finished) and I completed approximately 250 miles in her since fitting the ferrita exhaust and MTE remap. The car has been transformed, acceleration is very quick providing the tyres grip, even on ¼ throttle the car pulls like a dream. There is a bit of cabin noise especially at 2500rpm this stems from the full ferita exhaust system. The turbo spools up very quick and holds boost very well which I am a little concerned about, the standard boost gauge shows boost going past the solid white section and staying there until you lift your foot off. The concern started yesterday when I used the loud pedal to good effect, and as usual the car set off like a scolded cat but the engine revs spluttered ever so slightly as though the rev limiter kicked in. My concern is, was this detonation or just the rev limiter doing it’s job, I am a bit wary of doing the same thing, as the last thing I want is a bent con rod. I can not hear any knocks from the engine so I am hoping there is no internal damage, at the time I was not looking at the rev counter for obvious reasons, any ideas what may have caused this little cough?

[John_C]

Glad to see you've got the car back on the road mate, must be a monster with the DP as well as the cat back plus the remap.

Anyway AFAIK on a mapped car the boost gauge should show the boost going over the top of the white part of the gauge. Mine does

What gear and road speed were you at when you had the splutter, is it possible you span the wheels up so you bounced off the limiter for a second or two?

Have you tried checking to see if any codes have been stored? Not sure if that would show anything but it's an idea at least

Cheers,
John

[Chesh740R]

Could also be Spark Blowout as well.

How old are the plugs and what are the gaps set to???

[st5ve]

Originally Posted by John_C

Glad to see you've got the car back on the road mate, must be a monster with the DP as well as the cat back plus the remap.

Anyway AFAIK on a mapped car the boost gauge should show the boost going over the top of the white part of the gauge. Mine does

What gear and road speed were you at when you had the splutter, is it possible you span the wheels up so you bounced off the limiter for a second or two?

Have you tried checking to see if any codes have been stored? Not sure if that would show anything but it's an idea at least

Cheers,
John

Hi John,

The car has a auto box, I am not sure what gear I was in prob 2nd as I was doing 30mph when I stamped on the loud pedal. The tyres did spin so it is probable that the rev limiter was activated. Was to busy sorting out the torque steer. I have not checked any fault codes as I dont think any will be stored.

You are right John the car is a beast and sounds like one as well, press the loud pedal and the enginge barks off very nicely.

I may do another stage zero tune, I got the garage to do one some time ago aprox 9 months, but the car has done hardly any milage as was in garage for three of those. Will take the plugs out and have a look as Chesh740 has suggested.

[John_C]

I'd bet on you having nudged the limiter mate, once the wheels spin up properly your speedo will just flick round in the low gears. Time to get the suspension sorted for some more grip

Cheers,
John

[st5ve]

Originally Posted by John_C

I'd bet on you having nudged the limiter mate, once the wheels spin up properly your speedo will just flick round in the low gears. Time to get the suspension sorted for some more grip

Cheers,
John

Yep, the suspension does need sorting, although the car does sit fiarly well whilst driving under normal conditions, but as soon as you start to push the car, the weakness of the 12 year old standard springs and shocks can be felt.

Not sure if I want R springs and suspension or go for Eibach or Koni set up. I have 16" Metis Alloys on the 850 and they already fill the arches very nicely. Will have to look at some reviews before deciding me thinks.

[PNuT]

i hit the rev limiter in my car once... you know you have done it thats for sure!

[stusT5]

i had r shocks on mine now have bilstein shocks and eibach springs sport stuff not lowering much more responsive ride did you have the cat back on before putting the d/p on i have ferrita cat back with standard d/p does the d/p make a big difference on it's own mte is on the cards for the distant future

[st5ve]

Originally Posted by stusT5

i had r shocks on mine now have bilstein shocks and eibach springs sport stuff not lowering much more responsive ride did you have the cat back on before putting the d/p on i have ferrita cat back with standard d/p does the d/p make a big difference on it's own mte is on the cards for the distant future

stusT5, thanks for the info re shocks and springs, you say the car is more responsive with blistein shocks & eibach springs. In comparison to the R shocks is it a harder ride and was stability in cornering improved by much?

I had the full ferrita system in one hit and the MTE remap all from Don, the reason I had the down pipe at the same time was due to a conversation with IC, he said the turbo spooled up faster and their was some gain in hp as well, IC if memory serves correct had the catback system then added the dp and noticed a big diffrence. So I went on his recomendation and never looked back, I would recomend going for it, the ferrita system is top quality, you pay top dollar but it is worth it. I would also recomend Don he is a very honest trader and knows his stuff.

[st5ve]

Originally Posted by Chesh740R

Could also be Spark Blowout as well.

How old are the plugs and what are the gaps set to???

Hi Chesh, had a look at the plugs and they look good, the gaps are set to standard for T5 I had Volvo check them when I was getting other stuff sorted.