vz rpm limit? dodgy tuner? tuning question

[Dz811]

To anybody that knows a bit about tuning the alloytecs, i have a question.

i have a VZ 190kw sv6 manual, have had it dyno tuned, along with a host of other mods, have run a 14.9 before, so i know it's healthy.

I took it in to a tuner to have the RPM limit upped from 6700 to 7000. which i don't think is a huge ask, ive seen videos and instances of alloytecs revving that hitgh without too much of a problem.

the tuner called me not long after i dropped it off and said that it was already set at 7000, the engine just wouldnt get there... and then tried to tell me it was stretched timing chain and because its a tired old motor etc...

Now, i admit the motor has done 260,000 Kays (alot)... but the coils, plugs, injectors, intake manifold (cpr6), exhaust, 20%underdrive, and a host of other things are less than 20,000 kays old, i did an overhaul not long ago. and as i said, the motor is still as healthy as anything, it's run a 14.9 not long ago and still goes MUCH quicker than standard. It doesn't blow any smoke or anything either.

And i know when i hit the 6700 limit, its still pulling hard, it just hits a brick wall. it doesn't gradually slow down or feel like a drop in power, it just dies as soon as it hits 6700, the same as it did when i bought it standard 150,000 kays ago...

So, anybody that is knowledgable in tuning and these motors, is the tuner pulling my leg, or could it actually just be suddenly stopping at 6700 because of parts? There are no sounds from the engine or codes for timing chain wear, is there possibly a parameter in the computer that the tuner hasn't set properly?

 

[dijm8]

those things you've replaced isnt making any difference, like the tuner said it could be the internals that needs changing, has the timing chain been replaced in the last 150k ? otherwise i would be looking to do that

now i knw SFA about v6's but really but are you expecting? throw in some diff gears if u wanna pull harder otherwise save ur cash for when your off ur P's and get a v8

 

[Dz811]

No the timing chain hasnt been replaced, but regardless there are no rattles or error codes which indicate stretching.
And i wasn't saying the things i replced were going to make a difference, but they definitely wouldnt be causing it.

The idea im getting at is there's no reason why it shouldnt be able to rev higher than standard, especially since it's still more than healthy. And that all signs point to the rev limiter still being there even though he says it isnt.

please dont give me the "go buy a v8", that's got nothing to do with what im asking.
I know these motors quite well, ive pulled a couple apart and worked on many, my family alone has 2 (my brother has a wagon with the 175). That's specifically why I asked for information from an expert.

if you know "SFA" about the v6's then please leave my question to people who know more than me. Not having a go at you, there's plenty of motors i know nothing about, but i know these backwards.

 

[ParkwayDrv]

So what are you trying to achieve by upping the limiter in a 250k old motor?!

 

[Dz811]

So what are you trying to achieve by upping the limiter in a 250k old motor?!

it would bring benefits on the 400m times, because 1st and second gear are much shorter ratios in the manual than the autos, and would be lucky if it spends a grand total of 3-5 seconds there over the course of its entire life.
The internals (valves and valvesprings, cams etc.) are more than capable of running at that limit.
(its only 300rpm higher than stock ffs, there's alloytecs revving higher than that out there)

again, what does this have to do with my original question?

 

[Munz]

250+k engine
aftermarket modifications putting more strain on internals.....seems pretty str8 forward to me

I'd be doing the chain.

 

[DylanWillo]

Ide go with timing chain considering what everyone here is saying, and also agree with the other guy about saving for a V8 although this is alot that goes into putting one in.

do u know how many km's these other SV6's have done? mine just hit 120,000 and ive never hit the limiter but if your always doing it everything in the motor is getting thrashed and stretched, stock internals arnt really built for racing i dont think

 

[vn_v6]

you guys are all fkn stupid, answering un asked questions and stating things that have NOTHING to do with what he asksed, YES it can rev to 7000 and YES ur tuner is full of it, think about it the timing chain wouldnt make it impossible to rev to 7000 itd just be very sluggish up at those revs. take it to someone else

 

[Jesterarts]

you guys are all fkn stupid, answering un asked questions and stating things that have NOTHING to do with what he asksed, YES it can rev to 7000 and YES ur tuner is full of it, think about it the timing chain wouldnt make it impossible to rev to 7000 itd just be very sluggish up at those revs. take it to someone else

Well, obviously it can't otherwise we wouldn't be reading this thread now would we?

I thought that was fairly obvious.

I'm also impressed that you can make such statements without seeing, driving, hearing or working on this particular car.

I also suggest you do some reading in regards to timing chains as a stretched/worn chain can affect a cars ability to rev higher. A stretched chain could be causing a timing issue at higher RPM and just lack of power.

In direct response to the OP. If the tuner said the chain is stretched then why would you have reason to doubt him? And I will agree that considering the engine has been around the block a few times it could be causing it to not rev as high as you want.

If you don't trust him, then go elsewhere but without seeing the car you can't get a definative answer on here. Maybe the engine limiter is set at 7000rpm but some sort of any abuse software is kicking.

 

[torana355]

My limiter was set to 7k when i got my VCM tune done. It revs to 7k with absolute ease and my timing chain rattles quite bad.