Remapping a 90BHP to 140BHP

[B5-Passat-1988]

Seeking genuine advice. I've had a standard 110BHP to 140BHP remap on a B5 Passat before but i've never went over the standard limit. I heard about ones changing the 90BHP injectors and remapping the car, thus giving 140BHP. There is quite a few good re-mappers around where I live and they all will remap the car from 90BHP to 140BHP, fitting bigger injectors first. However I have been strongly urged not to fit bigger injectors by a family friend. He states that there is a highly likely chance this will ultimately lead to the destruction of the car. He says that the intercooler on my 90BHP would not be adequate and he was fairly positive that the egr valve would go through time, leading to a blown turbo and a massive bill. Perhaps I would be wiser not re-mapping at all or sticking to the standard 90BHP remap of anywhere from 118 to 125, depending on the quality/condition of my injectors at present.

Cheers!

[Eshrules]

I'd listen to your friend.

what's the vehicle mileage?

[adamss24]

I'd listen to your friend.

what's the vehicle mileage?
Esh, don't give advice without any research !

To the OP, mapping -if done properly- won't do any harm to the engine and the good old VE engines will double the power with just bolt on mods ! Larger injectors and a stronger turbo (from golf gt tdi for example) will unleash more power without any side effects bar slipping clutch IF the torque is not kept in stock !

[B5-Passat-1988]

Sorry I have been offline a while due to family bereavement. The mileage is 185K, 100% genuine. No issues or problems whatsoever with car. Smooth sharp wee car for a 90BHP. She just lacks a wee bit of umpf lol I am tempted to gather up a bit extra and go for a 130PD instead. Bore straight exhaust, remap "chooooooooooooooo" lol

[Eshrules]

Esh, don't give advice without any research !

To the OP, mapping -if done properly- won't do any harm to the engine and the good old VE engines will double the power with just bolt on mods ! Larger injectors and a stronger turbo (from golf gt tdi for example) will unleash more power without any side effects bar slipping clutch IF the torque is not kept in stock !

It was my opinion - you're entitled to disagree with it (as you often do) but it doesn't make mine any less valid than yours.

IMHO leaving an ageing engine alone (in regards to modifications, not general maintenance) is often the best route to take if you depend on it for a daily runner.

Assuming the decision made is to the contrary, the issue you're then presented with is finding a 'decent' remapper who isn't a fly by night outfit working on a cash only basis with no rolling roads to support their claims.

So when I said 'listen to your friend', I was referring to the sentiment - not the accuracy (or lack thereof) of his 'YOUR ENGINEZ WILL DIEZ' statement.

[B5-Passat-1988]

Thanks.

He didn't exactly say it will die, more that due to a combination of likely consequences of bigger injectors and remap that it would. He claims that the intercooler on a 90bhp wouldn't (long term) be beneficial to the bigger 110Bhp injectors as well as the remap. Thus leading to egr failure, blown turbo etc. His exact words were, "Volkswagen set it at a certain BHP for a reason, and messing around with injectors and remapping decreases the reliability of the engine long term."

[adamss24]

Thanks.

He didn't exactly say it will die, more that due to a combination of likely consequences of bigger injectors and remap that it would. He claims that the intercooler on a 90bhp wouldn't (long term) be beneficial to the bigger 110Bhp injectors as well as the remap. Thus leading to egr failure, blown turbo etc. His exact words were, "Volkswagen set it at a certain BHP for a reason, and messing around with injectors and remapping decreases the reliability of the engine long term."
I would be adamant to tweak one of the modern diesels- ie the 1.6 Tdi engine ! The old 90 Bhp engine is as tough as old boots, the rods will take 250Bhp all day long and- if you read my above statement- it will double the power with JUST bolt on mods ! Intercooler is good for 200 Bhp or thereabouts but the weak link is the clutch !
Contrary to what esh or your friend say, the old VE engine comes from an era when audi built cars not runabouts and because it made it to 185k without major issues proves my sentence ! I have seen 500k motors driven within an inch of their life with engines still original, the old ve engine is built for about 30000 hours which at an average of 30Mph is shy of a 1000000 miles...

[adamss24]

Also, the 90 Bhp engine is identical to the 110Bhp engine with the exception of turbo, nozzles and map- intercooler and most other bits are identical... The 110 Bhp engine tunes to over 150 with just a map...

[B5-Passat-1988]

Cheers pal. I did think everything bar what you mentioned was the same in the 90 and 110 model. One more quick question, please and cheers. Straight pipes? We all know cutting off back boxes is a big no no but I have heard that on a diesel older than 2002/2001 it is not compulsorary or necessary to have a back box or cats, as all diesels over this age fall into a heavy taxation bracket. Is there any point or would it be worthwhile installing a straight through pipe? Ive heard contrasting stories about 90bhps having little or no "choooo".

cheers again

[adamss24]

A straight trough pipe will be beneficial but the chocking point is still the small turbo ! Air velocity still apply but when tuning you need a decent compromise between spool and exhaust size, even though a large bore exhaust is better in theory- in practice is not that beneficial: just imagine a fluid flowing trough a large pipe and a small one !
The gt1749v as fitted on the 1.9Tdi engine is prone to boost creep in high rpm's so even with the vanes fully open the boost still raises, hence you need a larger turbo with a better flow map in order to minimize boost spikes. The gt1749vb off the 150Bhp PD Tdi ARL engine will do very nicely and it will support 200Bhp if you use 0.216 nozzles or larger...