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Discussion Starter #1
After looking forward all week to getting my 93 aero onto the rolling road, I ended up coming away with no dyno results .

The car has a speedparts ECU.

I put it on a rolling road near York, the garage having good equipment.

He couldnt get it up to high revs because the car was boosting to the TOP OF THE RED with the engine management light coming on and the power cutting out.

He has never seen this happen before on a rolling road.

My car has never boosted to top of the red (usually boosts a quarter into the red) and the engine management light has never come on before. After i left the garage the car was fine

So why has my car boosted to top of red on the rolling road, which I assume has triggered some kind of safety cut off?

What do people like Abbott do to get round this problem.

Looks like I am going to have to drive down to Abbott and get them to do it and get a few other mods done


I would appreciate responses as Im baffled and dissapointed

cheers
 

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cannot think whats happened here...
too high a gear perhaps ?
been to a rolling road with a bunch of other saabs and had no probs...
Abbott do not have a rolling road of their own btw so they would have to farm it out ...
Power engineering in uxbridge and emerald cams in norfolk are the ones that have done saabs before
a bit of a trek I know but also check the events as there is another group test at emerald soon...

sorry can't help...
 

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That's very odd, I've probably seen some 30 Saabs being run on a dyno and never seen anyone have problems with overboost-cutout UNLESS their car was overboosting when driving anyway!? Does your car have switchable TCS? Do you run it with the TCS ON for normal driving? If so try driving with the TCS disabled and see if you get overboost cutout.

One more thought, did they have a sufficient engine fan. If the fan wasn't blowing enough air into the rad and IC then the problems could have been due to heatsoak. I had this happen on my CD at a static RR, all it meant was the guy couldn't get it to hold full boost > 5000rpm. So my max power reading was taken from 5000rpm.
 

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Is your car a T5.
If so, I believe you are hitting the "pressure guard". It will activate at 1.35bar, if not disabled. I have seen cases with BSR/SP software where this pressure guard has been disabled.
When on rolling road, cars will boost more due to the added strain. This is normal.
My viggen will boost above 1.5 bar on dyno, but on the road I only get 1.4max.
 

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Discussion Starter #5
thanks chaps

to try and answer your questions:

Its a T7 (2002 aero)

I always drive the car with traction control on. On the rolling road he turned it off. To be honest i cant really tell the difference on the road whether it is on or off.

The fan was Big

He didnt rev high in the gears in fact he was going thru the gears quick up into 5th because of the cut out i.e. he never got to rev high.

Vigge - your point about the cut out seams logical.

I will phone abbott on Monday.

cheers
 

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Did the operator adjust the load on the road?  [/b]
This makes sense to me as my car suffers from overboost cut out when too much wheel spin is encountered,I have never had this when traction is good.
 

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I seem to recall reading of problems others have had when dynoing their T7 vehicles, and had to do with the rear wheel ABS/TCS sensors correlation with the front sensors.
 

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I've seen TCS give a problem before on a DI/APC 9000 but I haven't heard of/seen any problems with other models. At the risk of stating the obvious, I would talk to the Speedparts chappies first- talking to any other potential competitor is not necessarily the best way to solve the problem
 

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Originally posted by Mark E:
[qb]I've seen TCS give a problem before on a DI/APC 9000 but I haven't heard of/seen any problems with other models. At the risk of stating the obvious, I would talk to the Speedparts chappies first- talking to any other potential competitor is not necessarily the best way to solve the problem      [/qb][/b]
What I have hear the new 9-3SS is hard to dyno due to the same problem robert lavergne mentioned above, but with the T7 cars I havent heard of this problem before.

Contact speedparts, I wish you good luck with that.
 

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@mushdaffer,

I had this problem on my std 9-5 for about 30 minutes. The car was fine, I filled up with fuel and it started to really pull well with the needle going all the way into the red and tons of
. It then decided it was giving me too much enjoyment & wouldn't even go into the red at all. I started the car the next day, expecting it would have sorted itself out, but it still wouldn't boost properly. I needed to go somewhere & after about 70 miles it started to work normally again & never missed a beat since. Strange.

Sorry I can't help with a solution, but if you want to try another rolling road, there is a good 4WD one in Thirsk at Autogas 2000.
 

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Abbott don't have rolling road  [/b]
Taken from Abbott site....

Our Test Cell

The test cell is a sound insulated chamber on-site at Abbott Racing UK

I never saw a dyno when I was there but they have full info on their site and they have loads of outbuildings it could be located in.
 

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It's all in the terminology... "Dynamometer" is the generic name for an instrument that measures energy.

"Dyno" usually refers to the sort of test cell that you build an engine in to.
"Rolling Road" is the common name for a chassis dynamometer that you attach the whole vehicle to.
 

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Discussion Starter #16
I spoke to abbott. They said that a) it would be because of the fan is not providing what it should be, B) because of the ABS sensors something to do with the rear wheels not moving and how the sensors are affected

Im going to go to Thor racing in the midlands who dont use a rolling road but take the wheels off and do it that way.

Anyway still dont understand why all you chaps can dyno your car on a rolling road and I cant.

mushdaffer
 

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I think all of us with turbo cars probably see slightly lower than real world figures when RR'ing our cars due to:-

a: the cooling / fans at the rr
b: the load at the rolls provided by the rr
c: the spped of the run not allowing full boost to accrue at a given rpm

But, if you keep going back to the same rr and combine that with static reading's, you will see the differences between runs and the work you've done.

The higher your power (with a turbo and intercooler) the harder it is to get an accurate figure. on the road, cooling and traction will be greater.

Either way, I've been happy with the results i've seen at the RR session's i've been to and they reflect a good reading for the work done.

What work have you had done and what reading do you get??

Andrew
 

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Discussion Starter #18
i have the stage 1 speedparts, abbott back box, new filter and dump valve.

I have not got any results as my car would not dyno (read top of this thread)

cheers
 

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because of the ABS sensors something to do with the rear wheels not moving and how the sensors are affected

 [/b]
I'm curious about putting my Carlsson on the rolling road because of this. Although I know my TCS isn't working at the moment but as I have no warning lights and it hasn't gone into limp home mode I'm happy to leave as is at the moment.

Anyone else put their Carlssons on dyno and had any problems?
 

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Originally posted by Mark in Ireland:
[qb] QUOTE
because of the ABS sensors something to do with the rear wheels not moving and how the sensors are affected

 [/b]
I'm curious about putting my Carlsson on the rolling road because of this. Although I know my TCS isn't working at the moment but as I have no warning lights and it hasn't gone into limp home mode I'm happy to leave as is at the moment.

Anyone else put their Carlssons on dyno and had any problems? [/qb][/b][/quote]Mine has been on twice now.

TCS can sometimes back off the throttle until it gives up and lights the dash warning bulbs (clears ar next start).

The other option is to pull the rear 30A fuse in the little 3 * fuse and 2* relay box by the battery which sort the problems right out.

Andrew
 
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