My 3B Coupe project - Total rebuild

[AndyP]

Well I still can't get to the bottom of why it's boosting so late, I've leak tested it to death, changing the DV springs didn't make any difference. Here's a video of what its doing, this is short shifting into 3rd and the flooring it to the redline, from around 40mph

http://smg.photobucket.com/albums/v222/andys2/?action=view&current=Boostissue.mp4

As you can see it jumps up to 1bar straight away then sticks there until bang on 5000rpm where it builds to 1.5 bar.

Any suggestions greatfully received

[AndyP]

It won't fit in that location due to the fuel lines and FPR, I was looking at fitting an ABY fuel rail and lines but they wouldn't fit either. It seems to fit quite nicely in it's current location and is working a treat No sign of anything in the catch tank sight yet and the MAF to Turbo hose is staying dry.

[Rusty]

The bracket is designed to sit on the 2 stds that go into the IM; did you try it in this location, or did it not fit due to the battery?

All looks to be plumbed in correctly and a little catch tank to monitor effectiveness too

[EspenW]

I've just checked the logs again and it wasn't in 3rd gear, there was a change from 2nd to 3rd in that time. I'll try again this week and short shift to 3rd and let it pull through 3rd and 4th.

Anybody know what speeds the 6 speed box is good for in each gear? The GTech has me changing up from 2nd to 3rd at 65mph, I didn't think it went that fast in 2nd

Weight is 1540Kg inc me and half a tank of fuel.

Assuming 7200rpm limiter and 225/45/17 tyres:
2nd: approx. 68mph
3rd: approx. 98mph
4th: approx. 126mph

[A80Avant]

the problem is not a boost creep, but the lack of boost early on. This turbo on this engine should spool by almost 3000rpm not 5000rpm!

[newsh]

Which WGFV are you using?

Edit, sorry just read back a bit and see you're mapped on a spring.

The boost higher up could be boost creep, the wastegate not able to flow enough at high rpms for the size of the turbo. Hard to map round that without a WGFV.

[AndyP]

through the forge away and get an APR R1. it works much better.

i think the problem is the mapping though, unless the wastegate is creeping and that is why you are not building boost.

I've been trying to get an APR for weeks now. They cancelled my order in the USA because I have to order from a UK dealer, as of today none of the UK dealers I've asked have got back to me with a price
I've now got my cousin in the USA to order one and post it to me!

I also think that the answer is in the mapping, but I need to make sure that when the car goes back it is 100% fit.

[A80Avant]

through the forge away and get an APR R1. it works much better.

i think the problem is the mapping though, unless the wastegate is creeping and that is why you are not building boost.

[AndyP]

hmm 100 bhp missing there, what's the next plan Andy with this?

Not sure at the moment, still weighing my options. I found a couple of small air leaks this week that have now been fixed. This has not solved the overall boosting problem but the car definatley feels better.

I also found that the DV is passing a small amount of air at 1bar and more still at 1.5bar, so I've ordered a spring kit from Forge to see if I can get it air tight under full boost.

[AndyP]

I've just checked the logs again and it wasn't in 3rd gear, there was a change from 2nd to 3rd in that time. I'll try again this week and short shift to 3rd and let it pull through 3rd and 4th.

Anybody know what speeds the 6 speed box is good for in each gear? The GTech has me changing up from 2nd to 3rd at 65mph, I didn't think it went that fast in 2nd

Weight is 1540Kg inc me and half a tank of fuel.

[EspenW]

Did a couple of runs with the GTech this morning, too much tourist traffic about meant that I only got one clean run in each direction. Got a 60-90mph time of 4.4secs and comparing the old power figure ( which was backed up by a dyno run ) I think it has about 350bhp at the crank. Looking at the FATS times on the MRC data base this seems to match up pretty well with the power figure. More work to be done here obviously

The 4.4s 60-90 was a 3rd gear pull, right?
Stock RS2 was magazine tested 60-90mph in 3rd at 5.20s with passenger (test weight 1746kg). I tested a 400hp (Hohenester claimed) stage 5 (K26/27) RS2 to 4.00s 60-90 with passenger, so about 350hp at the crank on your makes sense.
B7 RS4 was tested to 4.50s with driver only (

[Jamo]

hmm 100 bhp missing there, what's the next plan Andy with this?

[AndyP]

Did a couple of runs with the GTech this morning, too much tourist traffic about meant that I only got one clean run in each direction. Got a 60-90mph time of 4.4secs and comparing the old power figure ( which was backed up by a dyno run ) I think it has about 350bhp at the crank. Looking at the FATS times on the MRC data base this seems to match up pretty well with the power figure. More work to be done here obviously

[Rocco]

hope you can discover it the soon as possible,because this stroker deserves it

good luck¡¡

[AndyP]

Tried fitting my old wastegate on Friday night in the hope it would cure the boosting issues in time for the rolling road on Saturday, but it was no different