First of all sorry for such a long post but...

I put my car on the rollers at yesterdays rolling road day at AmD, I have had a hesitation for a while on boost but thought I would see what its producing as it had a Jabba custom map 2 years ago by the previous owner (should be 214 bhp and 223 ft/lb torque). Well the first run yesterday showed 180 bhp and 215 ft/lb and the second run was 170 bhp and 205 ft/lb.

When he drove it off the rollers there was a small amount of white smoke, he drove it round the car park and parked it up and there was nothing. A couple of hours later the guy from AmD hooked it up to VAG-com as they were shocked by the lack of power and the big difference in the two runs and there was no fault codes but when he started it there was more white smoke for about 10 seconds and it then cleared.

He took it for a drive and said there was nothing obvious showing on VAG-com but he said the white smoke could be the turbo seals!!! Would you not also get smoke when driving if it were that?? Anyway, he did also spot a hose under the manifold at the front of the engine that had a lot of oil deposited on it and he did say that could be leaking so I will have a look at the when I get a spare hour or so!!

The car still drives as normal since and there has been no more smoke at all, I have let the car to stand and cool for 5-6 hours last night and did a short journey home from my girlfriends (about 8 miles) and there was no smoke at all. I started the car again this morning to check and still no smoke.

Do you think this could have just been build up of something in the exhaust as I really drive slowly normally and never thrash it or could it be something like the turbo is about to go bang??

I don't reckon it is the turbo oil seals mate, you would be seeing loads of white smoke out of the exhaust every time you booted it and it would be drinking oil like nobodys business (ask Westallc). The white smoke I would say is just a bit of condensation getting burnt off as you say you don't drive it hard that often.

I too would like to find out how my car (which RR'd at 188bhp at Impossible Performance) only managed to make 173bhp at AmD :S

Was there black smoke from the exhaust before the white smoke?

On lower mileage cars with good catalysts the soot gets caught in the cat which then starts to burn off as white smoke, this eventually clears if it's driven and cleared through kind of thing.

Still doesn't explain the figures though..

Kev

Strange results there! My first thought was you don't have a remap, and the seller made it up, since you conveniently made 180bhp.

But 215lbft is too much for a standard car. Standard is 173lbft. Do you know what peak boost you are running?

What other engine mods do you have?

I too would like to find out how my car (which RR'd at 188bhp at Impossible Performance) only managed to make 173bhp at AmD :S

This seems to be worrying you as you've mentioned it in a couple of threads. Maybe it's just the difference in rollers that people mention from time to time?

My first thought was you don't have a remap, and the seller made it up, since you conveniently made 180bhp.

Thats the wierd thing Bodge, I went out in Nicks car in April I think it was with my Liquid Gauge plugged in and it made something like 210bhp 223 ft/lbs torque, and 14psi boost, Nick had just bought the car and had been told by the garage it was standard, this was what prompted him to get in touch with the previous owner and found out it was remapped by Jabba.

For the OP, is the car using oil? If not, then you're just seeing build-up from the PCV and soot from the cat burning off.

On the point about RRs, it is a fact that power is affected by air temperature. pressure and relative humidity. Ok, typically only by 2 or 3% unless one of the RRs is several thousand feet up a mountain but there's a start on the difference. Similarly, all RRs measure power and torque at the driven wheels, so a new set of tyres vs a well-worn set could find another 1 or 2%. Also, different RR operators use different correction factors for transmission losses to get the flywheel figures they will quote you, and it's well-known that Jabba use one of the most optomistic corrections (I'm not saying their figure is wrong; just that you could "lose" several flywheel bhp by doing a power run at Jabba, driving over to Dave Walker at Emerald, and doing another run on his rollers, when both dynos return the same wheel figures).

When it was on the rollers there was a bit of black/carbon yes, again I put this down to the fact I never really get above 4500 rpm and that it was just carbon build up lol fingers crossed the smoke was nothing to worry about then!!

The only mods on the car are a green filter fitted by Jabba at the time of the map and a forge 007p dump valve fitted since.

The oil level was ok when I last checked it (a couple of weeks ago) I will check it again tonight though.

Once I found out it was mapped I did phone Jabba and they confirmed it had been custom mapped by them.

Edited 14 June, 201016 yr by Nickbes

14psi sounds too low to get 214bhp on a standard engine to me, maybe that's where the problem is. Maybe you have a boost leak Nick, but then you'd expect to see that on the VCDS.

APR Stage 1 ran 17psi, and Shark Stage 1 runs 19psi on my car. It used to boost to 11psi when on the standard map.

Weird one!

14psi sounds too low to get 214bhp on a standard engine to me, maybe that's where the problem is. Maybe you have a boost leak Nick, but then you'd expect to see that on the VCDS.

APR Stage 1 ran 17psi, and Shark Stage 1 runs 19psi on my car. It used to boost to 11psi when on the standard map.

Weird one!

You do not have to run high boost to get good BHP from a correctly mapped engine.

Also as Ken O'Neill has correctly pointed out, the temperature inside the dyno makes a big difference to the bhp figures, Chicken_eyebrow again asks where his fifteen horses have escaped to in the last two years when comparing the dyno at AMD against Racing Chariots one, but he would obviously have seen the great hole in the wall with an enormous power fan drawing in fresh cold air at Racing Chariots where as at AMD although they were using large fans, there was no direct link to these fans with the outside colder air., and when walking in there, it was a lot hotter than outside in the yard.

You do not have to run high boost to get good BHP from a correctly mapped engine.

Totally agree, but I've just never heard of anyone running such low boost on a remap before. It just stood out from the rest of the figures.

Obviously mapping without using increased boost has serious limitations. I wonder how much extra power you could get by remapping a totally standard engine, with the standard boost limit of 10psi. That would be really interesting to see actually. I'm guessing it wouldn't be much. Anyway......

Chickens standard map still made more power than Nick's custom Jabba map! So there must be something up with the engine somewhere!

I just checked the notes on my phone from when I Liquid Gauge'd Nicks car in April and it was 15psi, but I'm not sure if that was the peak figure or what it held. and the actual bhp and torque figures were 209bhp and 221 ft/lb torque so very close to what Jabba said it was when it was remapped.

Gerry I can see your (and Kens) point about the temps probably applies to my car and checking the paperwork the temp in the bay at AmD was 31 degrees whereas when we were at Impossible it was only 23 degrees. But I can't believe that high temperature would cause a 40bhp drop as is the case with Nicks car.

Shame we didn't get boost and AFR plots on the day too :|

Totally agree, but I've just never heard of anyone running such low boost on a remap before. It just stood out from the rest of the figures.

Obviously mapping without using increased boost has serious limitations. I wonder how much extra power you could get by remapping a totally standard engine, with the standard boost limit of 10psi. That would be really interesting to see actually. I'm guessing it wouldn't be much. Anyway......

Chickens standard map still made more power than Nick's custom Jabba map! So there must be something up with the engine somewhere!

My old Mk1 Octy vRS ran 238bhp and 250 lb ft torque at Marlins in Bletchley (Briskey RR day), and 233 bhp and 233 lb ft torque at Power Engineering at Uxbridge with under one bar (15psi) , so it is possible to get good figures with a balanced map, I do have dynos somewhere, and I think they were on the forum at one time, but the print out at Marlins was witnessed by all there.

The drop between run one and two on Nicks two runs seems to indicate heat soak more than anything else, for although there were two fans at AmD, there was no cold air feed to them from outside, so the hot air was just being recirculated, and, as stated when you walked in from the yard it was really a lot hotter inside than out.

As for the fourty (40) bhp drop in two years, did Nick get a dyno from the previous owner, or was it word of mouth?

Edited 14 June, 201016 yr by TheMethodFeeder

I just checked the notes on my phone from when I Liquid Gauge'd Nicks car in April and it was 15psi, but I'm not sure if that was the peak figure or what it held. and the actual bhp and torque figures were 209bhp and 221 ft/lb torque so very close to what Jabba said it was when it was remapped.

Gerry I can see your (and Kens) point about the temps probably applies to my car and checking the paperwork the temp in the bay at AmD was 31 degrees whereas when we were at Impossible it was only 23 degrees. But I can't believe that high temperature would cause a 40bhp drop as is the case with Nicks car.

Shame we didn't get boost and AFR plots on the day too :|

Yes, and if you remember yesterday, my first question to you about your drop in BHP was to ask if an AFR/Boost plot had been done?

The biggest problem is that all dynos figures should be taken with a pinch of salt, as they are only as good as the operator, the weather, the temperature and a host of other things that can all alter the figures you get between one RR and another.

You did state that your car seems faster than ever, well enjoy it for what it is, and don't worry about the lost horses, for if the RR at Amd had read fifteen more than at Racing Chariots, would you have asked for them to be removed, I think not.......LOL

Edited 14 June, 201016 yr by TheMethodFeeder

Well I had a look at the oil level last night and it was the same as a few weeks ago so don’t think its using much if any oil. I drove to my girlfriends, and back a few hours later and there was still no smoke of any sort and the car felt normal (well as normal as it can with the hasitation lol)

When myself and chicken did the liquid gauge test I remember it peeked at something like 18 psi and held at something like 15.5 psi and as he has said above the gauge was almost the same figures that the previous owner told me over the phone. When I called Jabba they did confirm that the map was done by them and the date it was done but said they had a new computer system since then and although they can tell from the invoice what/when it was done they no longer had the copy of the graph (as I asked them if I could get a copy).

Well hopefully the smoke was nothing to worry about as it seems to have been a one off, I just need to have a closer look at the pipe work for leaks etc. and if that doesn’t sort the hesitation I might try changing the N75?

Sounds promising on the oil front, looks like you have nothing to worry about there then.

That peak boost sounds spot on for a reading from a remapped standard car. Looks like Chicken found your car to be performing as it should. Just a case of figuring out how you've lost power since April! Must be related to this hesitation issue. The hunt begins.......

So that we're clear, I'm not saying if there is or isn't an issue with a specific car; what I'm saying is that a different flywheel figure taken on a different dyno, on a different day, with a different set of tyres, is a red herring when it comes to talking power gains or losses.

The hesitation can be helping things and that needs to get sorted then maybe see were you are at.

Dont get me wrong I love the idea of the road being Hot in there and thats the reason your power was a bit down as it means I would have more Hp in my car! Might have got me over 200 with-out a remap!

Great for pub talk!

But Chicken, like method feeder says there are variable etc and a result of 173 is only 4% off 180 so when you think about accuracy levels its not all that bad. Maybe you had a bad bit of fuel or something.

But when you think tibbs made stock and I made roughly what you would think with my mods. they cant have been that off. But heat levels in there prob do change quiet a bit so I dont know what accuracy level you would think it should be, but 4% isnt too bad I guess.

Yep that’s the plan, I am not that worried about the bhp it produces as long as I can clear the hesitation and then I will see how it is.

I had a spare half hour last night so I took the engine cover and the smaller plastic cover off. I could see a couple of pipes under the plate near the dipstick (the one with the N249 and N112 underneath) that were very oily, I think they both looked like they attached to the bottom of the intake manifold. I want to replace them so does anyone know the part numbers and also how the hell can I get to them as there is a lot in the way!!

Edited 16 June, 201016 yr by Nickbes