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Speed four after market exhaust mapping

6K views 34 replies 7 participants last post by  OraDBAforPsoft 
#1 ·
Hello there I'm back again.mid last year I bought a s4 in bits.I got her working fine apart the jerky bit between 3-4K rpms.After loads of reading it seems like this is a normal problem for the s4.i have tune ecu I just need help with adjusting the fueling to smooth out that bit. Apologies if this is in the wrong place.thanks in advance
 
#2 · (Edited)
Increase the fuel idle trim a little at a time. That should help. The other thing is to fill in the "hole" in the ignition timing between about 400 rpm and 4000 rpm. That should also help. Vacuum leaks and problems with the IACV also cause running problems, but it doesn't sound like that's your issue.

If your throttle bodies are not synched up, that causes similar problems. If the throttle bodies are feeding in different fuel and air at a given opening, that causes some throttle response issues as well.
 
#6 · (Edited)
You need to load the map you want to adjust into tuneecu first... from the pictures you have not loaded a map..

Best work practice is to load/read the map from your ecu first, then BEFORE you touch anything save it as the map number.backup eg: (200385.backup)

This way if you stuff it you have the original.

Sent from my SM-G930F using Tapatalk
 
#7 ·
Hi thanks for your posts. Last night I looked at the map that came with bike. I thought it was standard but it was the standard one that had been tweaked. So all I'm going to do is increase the fuel in the trouble areas and see if this helps. I also filled the hole on the other table. Thanks for everyones reply.
 
#10 ·
If it runs hot and idles lumpy, that's the usual sign of a lean condition. Since I don't know what map you have, that's all I can say. If the map is messed up, then all bets are off. I tried all kinds of experiments with no dyno to tell me what I was doing, and some things worked. Most did not. If that's a map somebody like me cobbled up, it's hard to know what works and what doesn't.
 
#15 ·
What year is your bike? I have a 2000 TT600 and had the dreaded 3 - 4k flat spot. My remedy was obtaining Triumph's map 10089 (2000 TT600 with aftermarket exhaust) and tweaking it with TuneECU. 10089 was a major improvement but far from perfect. I added fuel a few percent at a time concentrating in the 3 - 4k range and lower throttle settings initially. Over time my adjustments included "eyeballing" adjacent values and smoothing the curves in both the horizontally and vertical axis. After each change I road tested then made further tiny adjustments. After 9 generations it was perfect. You can compare my beginning and end points in the pictures below.

Note there were changes to the ECU for different years of the 600cc engine. I believe model year 2000 uses Sagem fuel injection that was replaced with something else later. You can still get an idea of where a stock Triumph map is lean by looking at the pictures.
 

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#17 ·
All S4s and TT600s used Sagem. Daytona 600 and 650s had Keihin.

The other place to look is at the timing map. When I had a 2001 and then a 2000 TT600, I ran the 2002 and later injection map with the timing curve altered. There's a "hole" in the timing around 3-4K rpm. I think that's a bigger issue than fueling. Just my opinion, so take it for what it is worth. What I did was even out the timing by changing those values to match the adjacent values. That made a big difference. Adding fuel can cause a rich condition which fouls plugs over time.

My take on what to do about a snatchy throttle - in order:

1. Make sure the IACV is sealed and all of the vacuum tubes are intact and connected.
2. Make sure the airbox is sealed up with no openings between the filter and throttle bodies.
3. Make sure the throttle bodies are synched up.
4. Adjust the fuel idle trim (CO) a little at a time.
5. Fill in the timing hole as mentioned above.
6. Adjust the fuel map to smooth things out.

There are other ways to do it and other sequences that will work. This is the sequence I used.
 
#18 ·
Thanks Will. I think i may have too much fuel in that area because the hotter the engine gets the worse it gets. I think im going to take out some fuel in them areas and see what happens. Last night i increased the fuel a bit and it started being snatchy straight away. So i think i will go the other way. Thanks for your reply.
 
#20 ·
Hi i know its been a while. My findings so far is ive been playing around with the map and not much progress. Ive realised that when the bike is on the warm up cycle and is reving about 2k i can smoothly rev it up to 3k without out it jumping straight to 3.5k from 2.5k. When the engine warms up a bit i cant hold 3k it just shoots from 2.5k to 3.5k.im guessing its something to do with more fuel on the warm up. Can anybody shed some light.

Finding no. 2 is that ive 2 things above the manifold that im guessing is some sort of emissions valve. They both have no hoses to them and are just open to the atmosphere. Im guessing they go back to the air box. Any help will be much appreciated. Thankyou.
 
#22 ·
Yea i put them back to the air box. No change to my lurching problem. Hopefully weekend i can strip apart the hoses and make sure everything is air tight then balance. Just was wondering its weird that it doesnt really do it untill the bikes idle drops down after warm up.
 
#23 ·
Check the stepper motor in the IACV and make sure the IACV is sealed up good and tight as well. It has a seam in its housing. You can reseal that with any RTV that works.
 
#25 ·
I don't remember exactly how everything went together on a TT600. It's been way too long since I bought the Daytona. I have thought about looking for a TT600 again, not because I really need one, but I kinda want one around to ride every now and then.
 
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