Easy 20-30 bhp gain from a 3 inch exhaust with 5 stud fittment, you could likely run the same power that you are now with 1.3 bar of boost.

tbh i think its down to a boost leak somewhere as got quite a bad idle when ya your driving say at 4k rpm+ then dump the clutch to come to a stand still it wont go back down and idle perfect it bounces around fora while just keeping itself running sometimes nigel had similar problem and that was few lil oost leaks he found. so gonna check it over and see where and if it is that as its got to be i think as its not flea's mapping as it had that before and it still doing it also counts out the PT map on the unichip cos the unichip is now gone also.

I was thinking that too but it is an RS @ 0.64 so I wouldn’t have expected much more BHP @ 1.5Bar. What torque did it make at PT? With similar mods to yours minus the cams about a year ago i made 335ft/lb 320BHP @ 1.7Bar at PT.

I have the same problem on my Bravo and on Squids 20VT too. Can't be both boost leaks can it? If you sort this let me know.

I've had the same on my car occasionally for 2 years now - I've replaced the AFM, idle control valve, plugs, coils, etc. I think it's down to the SIP personally, it only affects my car for a minute or so after starting, so I decided to leave it as it is.

When you turn up the boost past a certain amount you wont get much more power, just stronger mid range

I'd be worried if it was holding 1.5 bar right to the top anyway...

it affects my car all the time no matter how long its been running. wouldnt think mine has anything to do with the sip.


mattw, it isnt its about 1.2/1.3 at redline

turbo j, will do if i sort it which im hoping will do. also buddy on the old pt map it also made around 300lbs of torque so no change there with 0.15 bar more

what gains would i see if went bigger than 64 housing? or would it just end up being to laggy?

Not a lot - 10-20 bhp, but I reckon the small exhaust would not yield much more from the bigger housing, which will flow more at the top end - which is where the small pipe will strangle it. I doubt that the car would feel that much faster on the road as the extra power would only be in the last 1000 rpms.

You've got a sorted car the way it is now. Personally I would leave it alone and enjoy the car for a while unless you go forged and then GT2871 or GT30, and I would run less boost - but that is only my opinion. If you get all of the forged bits in 'stock' then go for a big turbo and budget for a build when the engine goes.

ive got rods and am in piston group buy



but on another note im self employed and things are really looking bad and as much as id hate it there could be an ink black 20vt for sale if i dnt get some decent work this month

Well - it will be worth a few hundred quid whole if the engine goes.

yeah no where near what its actually worth tho,

+1

As i said on saturday, a 3' exhaust would help

And imho my coupe dont feel very fast so i would'nt think you'll notice the extra power

Ben

Luke in my opinion you have nearly reached the turbo limit anyway. Increasing the boost pressure is only going to increase torque. Your boost level is safe for your setup (non forged). The exhaust made a big change on mine but I don't think you will like a 3" system, when mapping mine Rob said that the backpressure was far too high that’s why I got an exhaust, mine was an N/A exhaust anyway. I don’t think it’s worth changing the exhaust until your rebuild.




I have to agree with Si on this one, no point in changing the turbo until your rebuild. GT2871 or GT3071R is a good start depending.....





Just shows that the remap didn't change anything power wise, in fact it would be fair to say its lost power if you have increased the boost and the torque has dropped off by 3ft/lb and gained 3 BHP. Not to mention that I personally don't really believe the Powerstation dyno, Dastek is far more conservative when doing the flywheel calculations. It maybe down to the fact that flea pulls out more timing than Rob I'm sure Flea will be over to explain in more detail as to why. What were your WBHP at PT and at PS? What were the dyno room temps at PT and PS?


I think this is yet another weak point in the Bosch ECU. I’m glad to hear it’s not just mine and Squids cars behaving this way. I didn’t think it was a boost leak.

A very good point there - and worth bearing in mind is that any dyno I have been too has varied within about 30bhp, PT, PTS, Surrey Rolling road etc. You get an approximation, not a dead right figure.

Interesting, Luke's car went on a Dastek dyno with the PT map which had recently been calibrated by Dastek. It made 290bhp & 258lbs/ft @ 1.35bar. Nigel had never tested his car on any other dyno other than PT Dastek until last year, it made 270bhp on a Dyno Dynamics with the PT map and that's not forgetting he couldn't drive it more than a few miles without the map going off! I have tested 3 cars with PT maps and not one made the same power as they did on the PT Dastek dyno, indeed as Suba has mentioned, he and Highwayman lost around 20-30bhp on their PT dyno runs at SRR Dyno Dynamics. Fact is Jason, until you get your car on another Dyno then we'll really never know what your car is making other than "PT figures"



Another vacuous comment, how have you attributed this to the Bosch ecu? I have mapped 15 cars now and only 3 cars exhibit this idle behaviour.

Indeed - treat a rolling road as an opportunity to test the car is running right and an approximation of the power that it is producing.

I am going by the figures luke told me. I always ask for WBHP figures anyway as that is what is actually being measured. Flea we are never going to see eye to eye on the whole dyno thing. I will put my car on the DynoDynamics rollers at uni soon just to compare Dastek & DynoDynamics.



The question should be why wouldn’t it be the ECU?

Well that makes, Nigel, Me, Suba, Luke, Squid all experiencing the same issue. What do we all have in common....A remap on the Bosch ECU, if it was mechanical it should have been picked up by now. I just have a feeling it’s the ECU and if I’m right I hope you can find it & fix it. Not that I'm bothered now if you know what I mean

Mine is not mapped on the ECU - it's mapped on a unichip.

How about a 20v turbo engine with similar mods? If it was the ecu then they would all do it, but they don't. For those that do have idle issues, it is the same whether you have a bog standard chip, Unichip or remap.

True but the unichip only intercepts certain address lines to change values. The actual processing/map factors are still Bosch so if it is to do with the ECU I’m certain it would also affect unichip also.



It’s the same for the adaption, not all bosch adapts the map to an undrivable state. There are people having/had issues with adaption and others not. Nigels was a problem mine is not that bad, Squids in non existent.

I don't think the ECU can be ruled out. What do you think it could be then?

I can assure you 100% categorically that this is purely by chance.

Incidentally, what power has Squid made with his GT2871R 0.86?

Good point - I believe my unichip only changes the map open loop anyway.

we now know the multiple causes of my ECU behaviour - the PT map, whilst giving good power figures, was sufficiently rich elsewhere to cause the ECU to drift - Leighton has sorted it.

We also know that my poor idele was caused by two boost leaks, including a fairly substantial split in the intake rubber

Neither of these running problems could be attributed directly to the ECU

Turboj i can ssure you want flea done to my car didnt just change the car power wise 40bhp+ it changed the car totally to drive and how its soo much more responsive low down and its got it all round now and feels like an animal on the road compared to how it was when it put put 298 on the old Pt map.

im not getting involved with this not seeing eye 2 eye with u/flea but i will say flea has like he said done 15 coupes now and all he receives afterwards is praise about how hes changed the feel of there car. Look at carphone (DAN) at powerstation on sat. flea managed to get a standard car bunning at nearly 259bhp just from his remap and dan said the car feels great when i spoke to him.

turboj if you on unichip/PT map bite ya tounge take ya car to flea and see for yourself! what u got to lose. i assure you will be very happy with the outcome.

which at the end of the day is what its all about! There is always going to be debates over figures!

I'm not disputing the work flea has done to your car, it probably is more drivable I did say "power wise" I’m sure he has done a good job I am only going by the evidence you presented here:



The eye to eye with flea is only about what dynos were used nothing else. I don't have a problem with flea at all. In fact I much enjoy bartering with him

I don't need flea to map my car although I did consider it. My reasons are justified and it has nothing to do with his mapping ability. I will be mapping my car myself (Flea knows why)

Ok all that aside now I am more interested in the not being able to idle issue. Ok so with Nigel’s being down to a boost leak that still leaves me, luke, suba & squid with the same problem. Maybe I should start another thread regarding this.....

Either way I would be happy with your results luke

I think J is a little stunned that people didn't get their "pub figures" at Powerstation, he was soooo sure it was going to be a riot and then suddenly no.

Anyway, you still haven't said what you got at your last remap session or Squid? Stop dodging the question

Just to add into the idling debate, my car idled fine, until i fitted the SIP. I have a suspicion it is something to do with the positioning of the MAF

Leighton's way is the best way IMHO.

Unless of course I Unichip your car.