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Discussion Starter · #1 ·
Hi all,

Can somebody give me some more insight in the effect of hardware modifications (like intercooler, inlet pipe, sports cat etc..) on a stock programmed T7 ECU? Does the ECU adapt to them in a correct way?

Best regards,
Hans-Martin
 

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A number of people have noted that the T7 engine management does change a/f ratio slightly based on modifications to the engine.

IIRC some people found that installing an upgraded intercooler or exhuast made things run lean.

It should be noted however, that the engine can tolerate a leaner condition with better exhaust scavenging and intercooling. So far I don't know of any harmful effects from just installing a turbo back exhaust and intercooler.

Anything which alters the backpressure will change the Volumetric Efficiency of the engine. Getting more exhaust out of the cyllinders gets more air/fuel into them. Because there is less exhaust, there is less residual heat, so the cyllinders are not any more likely to detonate. However the engine has no way of knowing about the additional air going into the engine since it is programmed with the VE that the car had stock. When cruising the Air Mass Meter determines fueling. But when under load, it's open loop with the pre-programmed map, and I don't think it adapts enough.

At any rate, the T7 engine runs much like the T5 did at full throttle. So if the modification doesn't hurt a T5 engine, it probably won't hurt the T7 engine.

In fact you can run the T7 engine without the Air Mass Meter all together. Then you basically have a T5 engine with different internal bits and pieces, and a number of different ECU codes.

To be safe, buy a wide band a/f ratio meter before making any modifications. This will allow you to make sure you aren't doing anything harmfull. You can source an a/f ratio gauge here:

http://www.zeitronix.com/Products/zt2/zt2.htm

Keep on Saabin'!


Dubbya~
 

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Changing to a 3" exhaust + race cat can cause a CEL to light up with stock software. This info is confirmed by Fredrik of MapTun. Same goes for a big intercooler on stock software.

I had loads of hardware mods with stock software, and no CEL. Car seamed to run fine, but the dyno curve was very bumpy, there was not really much more power gaoin over the unmodified car and Tech reading showed down-adaptation by the ECU.

If you change the hardware, it is better to change the SW, too.

Yours,

Philip
 

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I am going I think for the Maptun Stage 3 and was thinking of getting the Abbott big intake pipe and turbo delivery pipe to get it up to 302bhp (on paper !)

speaking to a supplier for Maptun, he said that by adding the abbott mods it is unlikely that I will get the extra 22bhp as the ECU will compensate and hence still give me 280bhp.

I guess if I went abbott, they would map the ecu to account for the various add ons ??

I think this backs up what you are saying.


regards
 

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Discussion Starter · #5 ·
If you change the hardware, it is better to change the SW, too.[/b]
In the end, that is exactly my plan. I'm aiming at a Hirsch Stage 3 chip but simply can't afford the full hardware+software package at once. So I was considering to buy the hardware parts step-by-step and finish with the modified ECU. What I understand from the above is that I should wait spending money until I can go for all at once
 

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Abbott is not able to make custom ECUs. I am 100% sure of that.

If a supplier states: "This piece of equipement adds 10 hp", the statement is usally wrong.

For example, my car:

MapTun stage III Viggen 285 hp
Race Cat instead of Sport cat + 5 hp
Larger Intake pipe + 5 hp
Very large Race intercooler + 10 hp
Gas flowed head + 15 hp
Fine weighed pistons, fine balanced crankshaft + 5 hp

Total: 325 hp

Dyno result with MapTun Stage III 269 hp
Dyno result with Hirsch Custom ECU 280 hp

Limiting factors are the turbo and the fuel injectors. I could probably get more hp raising the fuel pressure (Vigge´s Viggen, which is quite similiar to mine minus the gas flowed head, dynos 290hp with stock turbo but uprated FPR), but I am driving high Autobahn speeds for longer distances, so this would put to much stress on the turbo. To get more power than I have and still have a reliable performace, I would need a larger turbo - which would introduce more turbo lag.

The Mitsu TD04HL-15T will not support more than 280 hp for a longer period, just for short peaks.

Yours,

Philip
 

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Originally posted by Hanm:
[qb]What I understand from the above is that I should wait spending money until I can go for all at once      [/qb][/b]
Basically, yes - but as I pointed out, adding the big downpipe plus racecat (plus cat back system) as the first modification might work for you. It just won´t give you much more power without the proper ECU programming. It will improve turbo spool up, though.

Although Hirsch was not impressed by my JT exhaust (they called it a "cheap exhaust"), I quite like it. It is cheap, does the same job than the much more expensive stainless steel systems (which, admittedly, will last longer and look even better) and sounds gorgeous.

Yours,

Philip
 

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Originally posted by MarkA (Saab 'M-F' 9-3):
[qb]As ever Philip, an excellent post. Off topic : what the heck are you doing in bosnia? [/qb][/b]
Thank you very much. Regarding my "short trip to Bosnia" (I will be there until the middle of September), I´m on a NATO peace keeping mission. Of course, I won´t go into details on a public forum, but I will get back to you tomorrow via PN. Sadly, I had to leave my Saab at home. Driving around in the Bundeswehr´s Mercedes G-model Jeep is already annoying me


Yours,

Philip
 

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Originally posted by philip hs:
[qb]Abbott is not able to make custom ECUs. I am 100% sure of that.

For example, my car:

MapTun stage III Viggen 285 hp
Race Cat instead of Sport cat  + 5 hp
Larger Intake pipe + 5 hp
Very large Race intercooler + 10 hp
Gas flowed head + 15 hp
Fine weighed pistons, fine balanced crankshaft + 5 hp

Total: 325 hp

Dyno result with MapTun Stage III 269 hp
Dyno result with Hirsch Custom ECU 280 hp

Philip [/qb][/b]
Hello, I'm new in this forum but already know personally some of the members.
I only wanted to "correct" some data posted here as I have the printout of the bench where this car has been dynoed:

Dyno result with Maptun Stage III 178kW at approx 4500rpm
Dyno result with Hirsch software 206kw at approx 5600rpm

This values are uncorrected power at the flywheel on a Bosch FLA203 bench.

So the powerdifference between MapTun and Hirsch Sw on the same car, same day is not 11 HP but nearly 30 kW and a huge rpm difference.
Would like to post this Dynoruns but I dont know how to do it.

Trionic
 

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Originally posted by philip hs:
[qb]Changing to a 3" exhaust + race cat can cause a CEL to light up with stock software. This info is confirmed by Fredrik of MapTun. Same goes for a big intercooler on stock software.

I had loads of hardware mods with stock software, and no CEL. Car seamed to run fine, but the dyno curve was very bumpy, there was not really much more power gaoin over the unmodified car and Tech reading showed down-adaptation by the ECU.

If you change the hardware, it is better to change the SW, too.

Yours,

Philip [/qb][/b]
One of the first things I was going to do when I get my 9-5 Aero soon, would have been fitting the full JT 3" system + d/p + sport cat with possibly the high flow intercooler.....

In light of the above....perhaps not now
 

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Originally posted by Trionic:
[qb]I only wanted to "correct" some data posted here as I have the printout of the bench where this car has been dynoed:[/qb][/b]
Do you mean my car? Please explain how you got the printouts? Did you break into my house?
The Dyno runs I am refering to were on May 27th 2004 at Heisel Motorsport in Merzig, Germany. The MapTun Software dynoed 198 kW and not 178 kW (better to compare the whp, as they are not corrected: 228 whp MapTun vs. 243 whp Hirsch).

While I was at Hirsch´s place, I did not have the MapTun ECU with me, so there was no comparison possible.

If you want more detail, please have a look at http://www.saabscene.co.uk/ubb/ultimatebb....pic/23/850.html

Yours,

Philip
 

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It is a little off-topic, but here it is



Yours,

Philip

P.S. It is in fact not very fair to compare these two graphs, as the MapTun software is a standard Stage III program, which is not aware of the changed intercooler and cylinder head. MapTun offered to make a Custom Program, too, but I´m very happy with the Hirsch program and not yet sure if it is really worth the travel from Germany to Sweden: MapTun might reach higher peak power, but the Hirsch program is very nice to drive and "playing it safe" for the engine.
 

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Let me also take part in this conversation since my car mentioned above by phillip.
These results have been posted before, but I'll do it again just for remainder. I have the same mods on my viggen (parts also, exhaust and IC) as Philip does, FPR is extra and no gas flowed head. SW by Maptun
 

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Of course all of this is very very slightly off topic.

I think the question is how the stock software would adapt, wasn't it?

Nicholas Taliafferro managed 230 whp on completely stock software with a larger intercooler, 3" downpipe, and BSR intake (I think).

Since the car dyno's at 212-214 whp stock, I think it would be fair to say he gained some whp from the modifications. Downpipes, intercoolers, and intakes don't make much hp on their own on most turbo'd cars. So the gains make it look like the stock ecu can manage them just fine.

I think many modified ECU's use a set-unadaptive program for the wastegate duty cycle. This has been the case in nearly any piece of aftermarket software I've seen. Very rarely are they as adaptive as the factory setup. The factory setup has to be able to deal with different conditions, wear and tear on turbo parts and other engine parts, and varying fuel grades.

If anyone has bad experience with the factory software they could prove me wrong, but I think the factory Saab setup is probably a bit better at adaptation than most aftermarket setups.

Here is a link to Nick's stock and stage 1 SpeedParts dyno chart. The stock is blue.

http://www.genuinesaab.com/dyno/Charts/Gra...ck%20chart.html

And here's a link to my stock dyno chart.

http://img5.photobucket.com/albums/v14/SaabTuner/211-206.jpg

The difference between mine and Nick's is about what I'd expect from the stock T7 software. The line remains fairly smooth. Then he goes and instals a SpeedParts stage 1 ECU, and because he is not at a stage 1 setup, it doesn't net much more hp over the stock ECU with his modifications.

Anyone have any different experiences with the stock software?

Dubbya~
 

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Originally posted by Adrian W:
[qb]If anyone has bad experience with the factory software they could prove me wrong, but I think the factory Saab setup is probably a bit better at adaptation than most aftermarket setups.
[/qb][/b]
Yes and no.

1 - Stock software is better than those setups that don´t adapt or try to gain hp by tricking the engine by faking sensor data. Hirsch software keeps full adaptation possibilities.

2 - On modified hardware, the stock software will always adapt down (we already discussed that in the other thread). On longer high speed runs or on bad fuel, it has not much room left for further down adaptation, which may cause trouble, if you know what I mean.

Yours,

Philip
 

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Originally posted by philip hs:
[qb] QUOTE
Originally posted by Adrian W:
[qb] If anyone has bad experience with the factory software they could prove me wrong, but I think the factory Saab setup is probably a bit better at adaptation than most aftermarket setups.
[/qb][/b]
Yes and no.

1 - Stock software is better than those setups that don´t adapt or try to gain hp by tricking the engine by faking sensor data. Hirsch software keeps full adaptation possibilities.

2 - On modified hardware, the stock software will always adapt down (we already discussed that in the other thread). On longer high speed runs or on bad fuel, it has not much room left for further down adaptation, which may cause trouble, if you know what I mean.

Yours,

Philip [/qb][/b][/quote]I hardly think it's fair to say that the software will always adapt down given some of the experiences of different people.

Probably going to rock the boat a little here, so bear with me.

Hirsch claim that the stock software always adapts down. Hirsch are also trying to sell you modified software. Even if they tell the truth in every case, there is a conflict of interest in relying on their word alone.

People who've done back to back dyno runs with the stock software using modified hardware claim that the stock ECU works just fine. They are also trying to show off the parts they just bought. Same conflict of interest.

So far I haven't really heard any reasons behind either line of reasoning.

If the stock ECU learns down, maybe sometime someone could get Hirsch to give an explanation to why.

If it learns up I'd like to see some explanation for that. (Aside from the usual reasons that are generally asociated with hardware mods.)

I personally am a little skeptical of the car learning down. It definitely learns up when you put some good gasoline in it.

I also think some hardware modifications could cause trouble. For instance a 3" exhaust and intercooler will significantly increase the VE of the engine. When the engine switches to MAP mode at WOT it will be using the stock VE as reference and could consequently run slightly lean-er and on poor gas this slight difference could case detonation, which would cause boost reduction and timing retard. IE, learning down.

But in the latter case, given sufficient octane, there wouldn't have been detonation, and a leaner mixture would have generated more power, rather than less. (Since the difference would be relatively small, perhaps from 12.5:1 to 13:1. Nothing drastic.)

Also a 3" exhaust can cause boost creep. It tends to raise the base boost, and few people adjust the base boost when the receive a new exhaust. So now instead of say 8 psi, it's 10 psi, and the computer can no longer drop it below 10 psi even if there is detonation from the leaner mixture and heat soaked intercooler at 120 mph on the autobahn ... you get the idea.

Buuuuut ... does that mean that the stock software learns down? Or does it mean that the modified hardware was not properly designed for the stock software?

Seen some evidence both ways. And don't just consider T7 cars. T7, as mentioned before, works very similarly to T5 at WOT. Those same changes to VE will affect T5, though perhaps in a different way.

If anyone has any qualitative reason why T5 would adapt up (which has been seen in nearly all cases) and T7 down, that would be most helpful! So far it seems to be a bit of a mystery.

Not that I'm comaplaining. I rather like the T7 stock software and hardware.


Any other ideas?

Dubbya~
 

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Originally posted by Adrian W:
[qb]Hirsch claim that the stock software always adapts down.  Hirsch are also trying to sell you modified software.  Even if they tell the truth in every case, there is a conflict of interest in relying on their word alone.
[/qb][/b]
I think you're bordering on the slanderous with that statement.

Can you actually recount documented cases of Hirsch not telling the truth or as having a conflict of interest?

Hirsch are the only Saab factory recognised tuner right now. Also, when it comes to trionic mapping, not only do they have complete access to Saab's documentation - they also have access to Saab's trionic development team, as is evidenced by the Saab factory trionic engineer present at Hirsch's when Philip's car's software was being custom written.

As is seen here :

http://www.saabscene.co.uk/cgi-bin/ultimat...pic/23/850.html

So given they have full cooperation with the Saab Factory, how can there be a conflict of interest?

And given that their access and knowledge of the subject (as evidenced by the fact that they actually write trionic software for a living) results in a defined working certified product, rather than some debatable anecdotal theories and experiments you have presented, might Hirsch actually be correct?
 
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