My first trackday session - partially ruined by the f*cking S2!

[iDub]

Just got back from a 20min trackday taster session at Bedford Autodrome. Great experience, and a good intro to track day driving.

First lap was awesome. The car was pretty quick, gripped nicely and braked better than I expected. 2nd lap sucked. Half way down the straight, in 4th at about 5-6k rpm with my foot to the floor, it starts kangarooing! Shat myself. Not a good feeling at that kind of speed. I backed off and put my foot down again. Same thing.

I was able to continue for the rest of the session, but couldn't go over about 0.5/0.6 bar boost. If I did, then it would feel like someone dabbed the brakes really hard as it lurched before giving power again. It would do this every 2 or 3 seconds. Very frustrating!

Temps were all normal, everything else felt fine. Got back to the car park, had a chat and headed home. Boosted as normal all the way to 6k in 3rd and 4th.

Any thoughts?

If it helps diagnose it, I've got a boost problem anyway. I hit 1 bar max at WOT, then it backs off to 0.6. If my foot isn't on the floor, it'll never go above 0.6 bar.

Any input gratefully recieved.

Matt

P.S. Even at 0.4 bar boost (just light throttle application) for the rest of the session I still did a few overtakes! Gotta love the S2 grip!

[Kieron20V]

Sounds like over boost protection interrupting the fuel pump and limiting boost. Get the codes read, check the MAF connector. Most likely its a boost leak. Have a search for boost leak test on here, and get yourself some leak test bungs if you dont have any.

HTH
Kieron.

[Rusty]

Boost leak or dodgy MAF connection. Take your time ironing all the miggles out and you'll have a very capable track car, especially in damp conditions.

[iDub]

Cheers guys. It was pretty good on track even only using part throttle. It'll be awesome once fixed and then homefried...

The car came with a boost leak test kit. I'll do a search on the forum to figure out where they go! How would a boost leak cause overboost? Surely it'll be under boosting!

Not quite sure how to test the maf connector other than a visual check.

[Kieron20V]

You need to check the pins in the connector, sometimes they can be pushed out if they're not aligned properly. Give them a good clean up too. I had the same issues on mine, very scary. My problems were cured by cleaning the connector and making sure it fitted snugly.

If you have a boost leak somewhere then the engine will be pulling more air than normal through the MAF so it figures something is wrong. Also if you have a leak in any of the plumbing between the MAF and the turbo inlet, then you will be drawing in unmetered air which causes problems too.

Kieron.

[iDub]

Makes sense! I'll have a go.

Thanks

[kwlw]

Makes sense! I'll have a go.

Engine goes quite wide in the engine bay during track day. Due to it's mass and abuse. This itself puts a lot of stress on the hoses also only on track boost hoses suffer from prolonged positive boost pressure/sudden vacuum changes. So it can also be boost leak easily. Also blown bov/bypass valve.

Sau

[Rusty]

I'll be selling solid snub mounts soon, that will tighten up the engine, help keep it all in place on track

[Greg_S]

Matt,

let me know when you plan on heading up there again since its not too far from me and i would like to get back out on the track. i need to get some spigot rings for the front first though.

[Audi_CQ]

If OK on first lap and OK when going home after some cooldown it sounds like something overheated. POS and/or coil(s) maybe. If spark gets weak it will not ignite on high boost.

[iDub]

Matt,

let me know when you plan on heading up there again since its not too far from me and i would like to get back out on the track. i need to get some spigot rings for the front first though.

I'll give you a shout fella. Apparently there's another novice session in December, if not it'll be in the new year. I like the idea of these short sessions as they're nice and cheap, plus they allow a decent test of the car. If this problem would have happened to me at the beginning of a full trackday, I'd have been gutted!

If OK on first lap and OK when going home after some cooldown it sounds like something overheated. POS and/or coil(s) maybe. If spark gets weak it will not ignite on high boost.

I thought something similar, it's pretty difficult to test though without going back out on track! What's a POS?

[iDub]

Ok, update...

Looks like everything I'm capable of testing has already been done:

http://www.s2forum.com/forum/showthread.php?t=37490&highlight=leak+test

Mental note - search the forum before buying a car! One of the major problems was collapsed cats. These have now been gutted (by Matt) and it's got a lot better. Still quite clearly not right though.

Looks like MRC will be getting a phone call followed by a large pile cash in the near future.

[AndyP]

I was interested in buying this car, but I knew about the faults, I sent him loads of messages asking if the boost problem was fixed but funnily enough I got no replys. He was obviousley hoping to sell it to someone who didn't read the forum so he could rip them off, nice bloke

[newsh]

Check theres not a leak where the little pipe goes to the ECU or the pipe to the boost gauge.

[Rusty]

Yeah, vacuum lines are always a boost leak favourite. Easy to replace with silicon stuff