My Polo GTI

[instigator]

I also think that might have been a disadvantage for him.
because he did not have a intercooler. (stock smic)
i used to have heatsoak on that event last year with stock smic, after the first race it was allready over,
now with IC my polo kept on pulling like an abosulute animal.
so i bet he had heatsoak from the beginning, from first race.
turbo is on higher boost so it must have somthing to do with that.
But i'm also not a fan of heinz chiptuning

so it's possible that we were running on about the same horspower,
race was also at the end of the day, long waiting times between each sprint,
so his heatsoak killed all of his power. to bad for him i guess,
he must have felt pretty bad :-p

[instigator]

hi again,
been along time i updated this thread...

since a couple of weeks ago i added new mods to my still unchipped polo (i know it's about time to do this...)
i know have installed the Forge Divertervalve 007 with the yellow spring.
the Forge throtlle body hose is also installed and the noise pipe is removed.
don't think i feel or notice any diffrence...
but the 007 DV blows much harder as the stock DV.
diddn't expect this as it runs on stock boost still.
i also removed the hood insulation, it was getting dirty and looked like sh*t,
gave me a weight advantage of 400Gr. also
maybe thats also i reason i can hear the DV more?

i also have a Forge TIP laying around for a week or so.
tommorow i will try and fit this.
read alot about it and seems to be a f*cked up job to do?
so i hope it will be worth it...
anyone got any tips for me about what i should or should not do
every bit of info is much welcome!
ps: anyone noticed any diffrence on a stock or even a chiptuned car??

talked to a chiptuner i know,
he will custom map my car arround March.
i hope i will reach about 230Hp and 350nM with my modifications
now the car has about 175Hp, measured with a Vbox, wich suppose to be pretty reliable...?

[sssstew]

So is the 007 worth it on a stock car do you think?

[instigator]

yes, i think it is worth it.
not that the stock one is bad, it will do perfect on stock boost.
but i diddn't expect any diffrence with the 007, but it makes quit a good noise

besides that, it won't be better as the stock one i guess.
my GTI will be mapped around March, so i was going to need it anyhow

[sssstew]

ok cool thanks for the info.

[instigator]

got it custom mapped today.
full stage 2 power

it was mapped on the road so i have no dyno cheet.
this will follow.
stock it made 0.6bar in mid range and @6000rpm 0.3bar.
now it makes 1.2bar in the middle area and @6000 it still got 1bar.
thats verry high for a K03s.
he spent 3hours of finetuning on it
pulls hard and strong all the way to 6500rpm.
did 240Km/u and had to let off due the traffic.

goes verry good and raced against a Golf V GTI Edition 30 with DSG and stock 230Hp.
rolling start in 4th gear and i immediantly took about 3 - 4 cars on him
from standing start i realy did have to wait for it to come by and then get his ass kicked
did a fast Gtech run on the way back.
0-60mph: 5.9sec
1/4mile: 14.4sec
i bet i can do better

only problem is, we think there is something wrong with the N75.
it goes good, but when i use it good a couple of times it gets wierd.
it probably build up heat or so and at 3500rpm it gets "bumpy", it looses power and build up, looses again, build up (verry fast) stuttering.
we don't know what the problem is, no false codes or so.
played with the diverter valve but nothing helped.
later this day i fit my mates diverter and see what it does.
thuesday i will fit a new N75 valve, hopefully it won't be something else.
anyone got ideas??

[noone]

Nice results.
So what was done other than the tune? Injectors, intercooler, etc. What sort of ambient temps.

N75's are a bit odd, you could try a J version, some cars work well with them.

[Plautos]

Go Polo GO!!!

About the N75... I had this problem once... so I changed the N75 for the ECS Race model... the problem was not solved, but it helped…
Try to get the WG tighten a little bit. Probably it is because it is too soft… remember the turbo was develop to charge only 1,2bar max… so the WG could be leaking pressure.
Do you have the downpipe done? With a good exhaust you can reach 1.5bar.

[insanekiwi]

Plauto, what do you mean by tighten up the waste gate? I have bit of fluctuation at top too, thought it was due to advanced timing... My Dyno chart is available on my thread... I don't feel the fluctuation but dyno did. Someone told me n75 is on the way out but not sure if it's correct as my boost is not fluctuating.

[Plautos]

Power fluctuation? I had this problem too… but only in the dyno… at the road I always felt the car strong. I never figured out where and what the problem was.

The n75 is only a tool to control the boost. It is not the right sequence to solve the boost fluctuation problem…

The stock WG only holds 0,4bar, tighten it a little bit, to hold 0,6bar then it will be easier for the n75 do its job.

Han, do you understand how the WG works? Positive pressure gets inside the actuator and opens a door at the turbo housing…. But some people forget that the turbo housing is also pressurized… so, if the actuator is not tightened properly, or the turbo is boosting more than it supposed to, exhaust gases will leak through the WG door… Causing the turbo fluctuations…

Try to tighten your WG… give it one or two turns… it is very easy, you can reach the turbo behind the engine… using a 8 or 10 wrench you can loosen the upper nut and tighten the lower nut.

[instigator]

thank for the comments and info.

today the car had it much worse as yesterday.

diddn't test in first gear as it was wet outside.
yesterday it was 26C°
today only 12.5C°
but it is noticable froml second gear (sometimes)
but from 3th - 4the and 5 it gets realy bad.
you can hear the turbo working, it wants to go, but somthing holds it back.
so once at 3 - 3500rpm it realy starts to fluctuate verry bad.
the whole car is shaking.
it has trouble to go pass the 3500rpm but when it does, it goes a bit better with minor fluctuations, but at 5000rpm it starts again, but not that bad as on
3500rpm.

i stay under 3000rpm with it because i realy don't want to destroy anything.
hope we find out what it is...

i don't think the tuner has done anything to the wastgate.
he said something about it, practicly the same as said here.
but stil he thinks there is something with the N75?
maybe a bit of both?
theusday a mechanic will drive it and see what he thinks of it.
i talked to him on the phone and he thinks it has to do with "not enough fuell"
so maybe injectors or so...? or placing a 4bar FPR?
but its hard to diagnose a problem over the phone.

upgrades i have now are:

Full milltek: downpipe with sportcat, non resonated
K&N airfilter 57i open cone (maybe the oil damaged the MAF sensor??)
Forge turbo inlet pipe
Forge throtlle body hose
Seat sport intercooler (does the job guit well, intake temp was 32C° with outside temp of 26C° and driving hard while mapping it)

maybe you guys have a better view on things now and help me out to find out the problem?
i'll def. look into the WG thing.
thanks for that!

[kangfu]

If its the stock N75 i think that may be the problem. I had better results with the N75J, but then better again with the N75 Race.

I have a spare N75J i could lend you but i see you're in Belgium :p

[noone]

Very difficult to diagnose remotely... As the N75 was fine before I don't think I would assume that is the issue, although could be...

Check all your pipes are properly connected, the added boost may have caused a leak.

[instigator]

i did a pressure test the day before, had 2 leaks but everything is sorted out.

when the car is getting mapped or finetuned and a new program is loading in,
the car runs good and fine, strong and powerfull for about 5 minutes, then he starts to get the fluctuations

going back to the tuner today, hope he can fix it

[Spec83]

Are you running the stock diverter valve... That could be opening causing problems?? If it is n atmospheric one, I would be trying a plub back and see how you go!!

Sounds like a heat related issue if it is only occurring after 5 or so minutes!!