Hi Guys,

I put my car on the rolling road on Saturday and was pleased with the results but I have a got a couple of questions and was wondering if some of you guys with more knowledge than me would be able to help me out.

The print out from Saturdays run is below



The car made 302.6BHP and 276.3LB.FT

The questions I have are firstly the dip in the torque curve between 4K and 4.5K, it’s not something I ever notice when driving but is there anything that would cause it or is it fairly normal?
Secondly the boost is down to what I would expect, it’s very smooth but it peaks at 1.2Bar and tails off to 0.9Bar. Now my car has got a Defi boost gauge fitted and it always shows a peak of around 1.4Bar and then it tails of towards 1.1Bar. What would cause the boost to be lower whilst on the rollers? less load on the engine?? or is it likely that the Defi gauge is out?.....would hope not for the price


I have also got two more graphs from a previous run the car did a few years back. These don’t show any dips in the torque curve. The torque figure is a fair bit higher as well at just over 300Lb.ft but the power is down.






Now I’m more than aware that there is a variation in figures between different rollers so I’m not worried about the actual values but i would have expected the shape of the curves to be more or less the same.

I'm still happy with the results, just looking for a better understanding of what it actually means and why it might be different.
Although if i average the two results then the car pretty much hits the quoted prodrive figures on the head

Any thoughts or comments are welcome

 

Hi mate. I'm no expert of rolling roads, so won't comment on them, except that I've had some big variations between the 2 RRs I've used on the same spec. I would rely on DD figures more.

Defis are well known to over-read, although cars don't always make the same boost on the road as they do on the rollers.

 

Which year an model is this?

as its 302bhp can only assume its the STi hatchback. I've seen them make 315bhp stock, but the torque is normally way up well over 300 ib/ft

 

sorry its a 2003 Blob STi with PPP

 

The only time ive had mine on the rollers it also made 302/287 so seems about right

 

Pat Herborn told me to knock .1 off any readings on my deffi boost guage and that seems to square up with my results on Zen rollers and Butty's road dyno

 

You might have had a wee bit of knock causing the slight dip at 4200rpm's...

Could be down to the fuel used on the day.. (If you've not noticed it before)

my 2003 STI was really sensitive to knock, and it took all of Bob Rawle's skills to get 320bhp out of it, when he was was regularly getting 330+ on other STI's.

 

Cheers for the replies guys,

Can't believe the Defi gauges are inaccurate...for the cost but even the 0.1 rule of thumb the car still made less then they suggest......guess the engine may have been under less load as well.

That don't sound good, surely the ECU would throw up an error code if the engine is constantly knocking??? Fuel was V-Power as always...never put anything else in the car was a fresh tank the night before.
Is there any way to tell if the engine has got a knocking issue??

 

It will not be "constantly knocking", but DET can occur in the mid rev range on WOT and full boost, the ecu will pull the advance quite sharpish if it's loud enough, causing that slight hesitation. No you'll not get any CEL warnings untill it's too late..

Buy a knocklink, fuel varies from place to place and tank to tank... best mod I did.

I was just about to say look at my garage for the knocklink mod...but it's gone... mods? where's my garage gone?

 

Forgive my stupidity but what is WOT?
I didn't hear or notice anything whilst the car was on the rollers and I was stood right next to it.

Also would there not be a dip in the boost curve at the same point as well?

Finally but what is a knocklink???

 

WOT is wide open throttle, a knock link measures knock/det on the engine

 

cheers for the reply.

 

You'd need headphones (cans) on the block to here DET mate

A device that listens for DET (knock) and alerts the driver by a row of lights (green to Red, green being ok, then yellow (ok'ish watch out) to Red, (major DET back off the throttle))

My knocklink install on my old STI (row of lights above stereo and right of cup holder)

 

Yes mate, they are still on

Although I’m thinking of removing them for next year’s show season.....let the car progress to the next stage...more discrete and more power

I’m half and half at the mo....first thing will be get the wheels and brake callipers recoated at some point in the new year (same colour just a to refresh them). After that I will decide as I want the car to undergo a full paint correction so it will either be just on the visible paint work or on the entire car with the graphics gone.

 

Knocklink is so 90's

New bells and whistles knock detection kit: AZTEC PERFORMANCE ONLINE STORE - WHOLESALE PRICES DIRECT TO THE PUBLIC - Knock Analysers :: KS3 Knock Analyser

 

It's not unusual to see more boost on the road than on the dyno. On my previous level of tune, the boost max. level after a rolling road session showed up on the PSi3 meter as 1.35bar but I'd seen 1.45bar on the road.

JohnD

 

Now if that had been a blue tooth KL I'd have been impressed

 

roflol.... stick to selling HID's and Clutches then!!!!

Nowt wrong with MAHA RR's if used correctly.

Knocklinks work, but of course you don't sell them do you! IMO any of these devices for this level of tune are not warranted for a normal owner.

CWB,
Looks like some ignition maybe being pulled at the top end.... TMIC heat issues on the rollers. Non ideal cooling on the RR etc etc. Quite normal for a PPP map though.

Always good to ask for DET CANS to be used by the operator when you have a RR run done. The operator can then check for DET during a run and it won't cost you anymore to have them do this. Fueling should also be checked.

If you are concerned about the dip take your car to an ECUTEK dealer and they can use a software package called Deltadash to log what is going on. Either on the road or dyno. They will then be able to diagnose any issues.

 

The first run done on zen's rollers would have been using Paul's superb fan - don't think heat would be an issue there. As Shaun said though it does look like timing is being removed at the top ( and in the mid rpm range) possibly from det that is occuring at that time or has occured recently and learnt.

If Paul has not mapped the car, then I am not sure he would have the det cans hooked up for just a power run.

Not only ecutek dealers can log a car and advise on what needs to be done to improve/correct it.

As said about Defi's, I know they look nice but really they are hopeless as far as gauges are concerned as they are almost always inaccurate.

 

As I've been running dyno cells longer than just about anybody I suppose I'm entitled to comment on threads like this. But I don't and I won't. If you're not there using the equipment in a touchy feely way you can't really give any kind of opinion on it. It's the difference between using a flight simulator on your home PC and actually grappling with the joystick on short finals with a crosswind component. If there are any questions to be answered, the dyno pilot is the only one to ask.

 

Sorry Shaun,

but I have to disagree with your KS3 statement, mine saved my engine when it went crazy on the M62 recently, a second later the Defi boost gauge joined in, and I got off asap.... Lucky win for the Monaro then ?

Turned out my 18 month old silicon pipe from turbo to actuator had split and fallen off, causing the boost to reach a slightly worrying 2.1 bar (approx.).....

So to sum up a KS3 is useful on any car that is used hard or modified, IMHO

dunx

 

bells and whistles knock detection sounds great. i think ill find it easier if i heard the det rather than look for CEL when traveling at speed

i thought on any dyno run done you should hook up the det cans just incase

 

Joker. Won't take the thread off topic, but a VHS player performs the same basic function as a Bluray player but you wouldn't go out and buy one

As you're the resident dyno queen, do you know what RR PTS in Luton use?

 

ROFLOL @ Bob.

I have no idea what PTS have now, but they did have (back in the days when I owned Cossies) some fairly old piece of equipment.



I hope they have at least updated their cooling fan!!!!

I'm not sure if it was an old SUN dyno iirc.

Dunx,
We are on about a PPP car here, which is the level I was referring to. Wouldn't the boost cut come in if this specific car started to overboost to 2.1bar.

 

Dunno Shaun,

but just saying there isn't a car out there that COULDN'T benefit from said device..... well o.k. a sport maybe



dunx

P.S. That isn't your Rover 200 on there is it ?

 

You love it Shaun

I had mine at PTS a few years back (before I knew any better) and it made 352bhp with just 290ft/lbs of torque (from memory). Took it to a DD and it made a more realistic 340/340 with a dash of meth and no map changes.

Not the most professional outfit I must say, the owner of another car (FWD) wasn't too happy when his front bumper was being yanked off at just over 300bhp