Scott Posted May 30, 2011 Share Posted May 30, 2011 I'm sure Ryan would be the best person to ask about this but I thought I would try here first to save hassling him privately. I'll use examples for simplicity... Say you have a car mapped to 700hp at 1.8bar. What sort of lower boost levels can you run without having to adjust the map? There are lots of people running dual boost settings without having dual maps. Just wondering what the limitations are. Now I know that dual maps would be the best option but just thinking of cost constraints etc, if I can get away with dual boost settings rather than dual maps I would probably just go with it. Cheers Quote Link to comment Share on other sites More sharing options...
Ricky49 Posted May 30, 2011 Share Posted May 30, 2011 I have 4/5 boost levels which I can flick between using a switch on the dash Quote Link to comment Share on other sites More sharing options...
Scott Posted May 30, 2011 Author Share Posted May 30, 2011 I have 4/5 boost levels which I can flick between using a switch on the dash Do you know what the highest and lowest are Ricky? Are they mapped in or just boost alteration settings? Quote Link to comment Share on other sites More sharing options...
heckler Posted May 30, 2011 Share Posted May 30, 2011 I'm sure Ryan would be the best person to ask about this but I thought I would try here first to save hassling him privately. I'll use examples for simplicity... Say you have a car mapped to 700hp at 1.8bar. What sort of lower boost levels can you run without having to adjust the map? There are lots of people running dual boost settings without having dual maps. Just wondering what the limitations are. Now I know that dual maps would be the best option but just thinking of cost constraints etc, if I can get away with dual boost settings rather than dual maps I would probably just go with it. Cheers I have a dual boost setting on mine, done by a switch. all its does is limit the boost. If you ask me the lower boost limits are irrelivent as the car has been mapped to (in your example) 1.8 bar Quote Link to comment Share on other sites More sharing options...
Scott Posted May 30, 2011 Author Share Posted May 30, 2011 I have a dual boost setting on mine, done by a switch. all its does is limit the boost. If you ask me the lower boost limits are irrelivent as the car has been mapped to (in your example) 1.8 bar If the map is expecting 1.8bar surely if you cut it back too much, say 0.5bar, it would run MEGA rich? I understand that there is automatic headroom in the map, and the ECU will pull the timing/fuel etc to match. It's just a pull though, not a proper map so I wasn't sure how far it can be taken. Quote Link to comment Share on other sites More sharing options...
heckler Posted May 30, 2011 Share Posted May 30, 2011 If the map is expecting 1.8bar surely if you cut it back too much, say 0.5bar, it would run MEGA rich? I understand that there is automatic headroom in the map, and the ECU will pull the timing/fuel etc to match. It's just a pull though, not a proper map so I wasn't sure how far it can be taken. no, becasue during the mapping process, its been mapped at these levels. Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted May 30, 2011 Share Posted May 30, 2011 it will fuel relevant to your map sensor so when the map sees less boost it will lower the inj duty aswell. Quote Link to comment Share on other sites More sharing options...
Ricky49 Posted May 30, 2011 Share Posted May 30, 2011 Do you know what the highest and lowest are Ricky? Are they mapped in or just boost alteration settings? I think its 1.7,1.5,1.4,1.2,1 bar, Im sure these are just boost alteration Quote Link to comment Share on other sites More sharing options...
Scott Posted May 30, 2011 Author Share Posted May 30, 2011 no, becasue during the mapping process, its been mapped at these levels. it will fuel relevant to your map sensor so when the map sees less boost it will lower the inj duty aswell. Right I'm confused then. Why does a car need re-mapped when the boost is increased then? Surely if it was that simple more boost would mean higher injector duty? Map sensor sees more boost, ECU adjusts accordingly? Quote Link to comment Share on other sites More sharing options...
Scott Posted May 30, 2011 Author Share Posted May 30, 2011 I think its 1.7,1.5,1.4,1.2,1 bar, Im sure these are just boost alteration Thanks, that is the sort of thing I'm looking at. I would only be after 2 settings though, I'm thinking around 1.2 and around 1.7 (or whatever gets me to around 700). Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted May 30, 2011 Share Posted May 30, 2011 Right I'm confused then. Why does a car need re-mapped when the boost is increased then? Surely if it was that simple more boost would mean higher injector duty? Map sensor sees more boost, ECU adjusts accordingly? your talking about bpu there getting the maximum out before injectors are flatout. ive had a car mapped to 2.2 bar on a 3 bar map sensor which technically shouldnt be doable but all he did was map it to fuel for 2.2 bar when the map sensor sees 2 bar the problem with this is if you do then run 2 bar it will be rich as theres no actaul 2 bar site in the map, but if i wanted to go down to say 1.6 bar it was fine. my supra was mapped at 2.05 bar and i watched it on the dyno at 1.65 to 2.05 bar on all 3 boost settings and the fueling is fine. at the end of the day any tuned car should have a wideband on the car all the time you know what its doing then as you alter the boost, mine holds around 11.1 afr at wot. Quote Link to comment Share on other sites More sharing options...
Scott Posted May 30, 2011 Author Share Posted May 30, 2011 your talking about bpu there getting the maximum out before injectors are flatout. ive had a car mapped to 2.2 bar on a 3 bar map sensor which technically shouldnt be doable but all he did was map it to fuel for 2.2 bar when the map sensor sees 2 bar the problem with this is if you do then run 2 bar it will be rich as theres no actaul 2 bar site in the map, but if i wanted to go down to say 1.6 bar it was fine. my supra was mapped at 2.05 bar and i watched it on the dyno at 1.65 to 2.05 bar on all 3 boost settings and the fueling is fine. at the end of the day any tuned car should have a wideband on the car all the time you know what its doing then as you alter the boost, mine holds around 11.1 afr at wot. I think you're missing my point. I'm not talking about BPU. Lets take your car as an example though... What would happen if you had your car mapped to 1.2bar, everything running great, and then decided to crank up the boost to 2 bar? Everything would be rosey? Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted May 30, 2011 Share Posted May 30, 2011 I think you're missing my point. I'm not talking about BPU. Lets take your car as an example though... What would happen if you had your car mapped to 1.2bar, everything running great, and then decided to crank up the boost to 2 bar? Everything would be rosey? of coarse not it doesnt work that way it must be mapped at the highest boost setting first. your op is about running lower boost pressures not higher. Quote Link to comment Share on other sites More sharing options...
Scott Posted May 30, 2011 Author Share Posted May 30, 2011 of coarse not it doesnt work that way it must be mapped at the highest boost setting first. So it's ok to run lower boost than the map is catering for, just not higher? It's not making sense to me. You are saying the map sensor sees the boost and the ECU accomodates it, surely if it can accomodate it for lower boost it should accomodate for higher? Do you understand this fully or are you going on what you have been told? Just asking as you aren't putting forward any concepts for the idea. Quote Link to comment Share on other sites More sharing options...
JamieP Posted May 30, 2011 Share Posted May 30, 2011 As long as you dont go over the peak boost its mapped for it makes no odds, you can run it as low as the WG spring will go should you like, ive never seen the point in adjustable boost myself, i keep mine full boost all the time, if i dont want to go fast i dont put my foot right down. Quote Link to comment Share on other sites More sharing options...
Scott Posted May 30, 2011 Author Share Posted May 30, 2011 As long as you dont go over the peak boost its mapped for it makes no odds, you can run it as low as the WG spring will go should you like, ive never seen the point in adjustable boost myself, i keep mine full boost all the time, if i dont want to go fast i dont put my foot right down. Ok so when the car is mapped everything inside the maximum boost level is covered? That's pretty clever stuff then. So would that mean you could remove the turbo and everything would run fine? I guess that's why base maps are quite common to get people to and from mappers? Everything outwith the boost is covered, the car then needs mapped for boost. I was thinking more of engine conservation lol. Keeping the "high" boost for those special occasions if you know what I mean. Running around the 700 mark I think I'll be pushing my luck a little so I don't want to do it too often. Quote Link to comment Share on other sites More sharing options...
JamieP Posted May 30, 2011 Share Posted May 30, 2011 Ok so when the car is mapped everything inside the maximum boost level is covered? That's pretty clever stuff then. So would that mean you could remove the turbo and everything would run fine? I guess that's why base maps are quite common to get people to and from mappers? Everything outwith the boost is covered, the car then needs mapped for boost. Yup, dont ask me how they do it, a good ecu such as the syvecs helps id say, when Ryan was mapping my V8 with the Link ecu he had to map every rpm load on the dyno, took ages compared to when he mapped the black beast. Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted May 30, 2011 Share Posted May 30, 2011 So it's ok to run lower boost than the map is catering for, just not higher? It's not making sense to me. You are saying the map sensor sees the boost and the ECU accomodates it, surely if it can accomodate it for lower boost it should accomodate for higher? Do you understand this fully or are you going on what you have been told? Just asking as you aren't putting forward any concepts for the idea. lol any concepts, do what, what are you talking about man. im not a mapper no but ive had alot of tuned cars and its not the best idea to own and tinker with these cars if you have no clue how they work, just take it to a tuner DO NOT JUST INCREASE THE BOOST ive told you what was done to my car not just hear say things as i said, tbh ask a tuner i cant see any point in me trying to share my understanding of it with you anymore ! Quote Link to comment Share on other sites More sharing options...
Scott Posted May 30, 2011 Author Share Posted May 30, 2011 lol any concepts, do what, what are you talking about man. im not a mapper no but ive had alot of tuned cars and its not the best idea to own and tinker with these cars if you have no clue how they work, just take it to a tuner DO NOT JUST INCREASE THE BOOST ive told you what was done to my car not just hear say things as i said, tbh ask a tuner i cant see any point in me trying to share my understanding of it with you anymore ! In fairness Jamie covered it in one post, exactly what I was asking. Si mentioned it earlier also but didn't reply again when I queried the inner workings of it all. I think you would be surprised what I understand and don't understand about fuelling and the issues regarding mapping etc. This is the reason I asked for an explanation rather than a "just because" response from you. You had the "just because" well covered, but the understanding of it was sadly lacking hence why I had to keep probing... and eventually just came out and asked you if you knew or whether you were feeding from second hand information. You can tell me you know something, but until you give a reason why I won't just settle for it as being the truth. I'm just an engineer at heart, I want to know how and why things work... not just that they do Quote Link to comment Share on other sites More sharing options...
bigbloodyturbo Posted May 30, 2011 Share Posted May 30, 2011 If the map is expecting 1.8bar surely if you cut it back too much, say 0.5bar, it would run MEGA rich? I understand that there is automatic headroom in the map, and the ECU will pull the timing/fuel etc to match. It's just a pull though, not a proper map so I wasn't sure how far it can be taken. I would have thought if the car was developing 1.3bar instead of 1.8bar then the ecu would use the injector pulse width next to the load cell at 1.3 instead of 1.8bar. Surely at WOT the ecu will be in closed loop and looking up tables according to load/rpm/manifold pressure? If the manifold pressure is lower then it would just look up the figure for that value, thats how i understood it, prob wrong though:) Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted May 30, 2011 Share Posted May 30, 2011 lol what exactly has been explained then ? nothing as far as i can see other than map it at full boost and it will sort itself out for everything below it, what else exactly has been explained ? lol Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted May 30, 2011 Share Posted May 30, 2011 I would have thought if the car was developing 1.3bar instead of 1.8bar then the ecu would use the injector pulse width next to the load cell at 1.3 instead of 1.8bar. Surely at WOT the ecu will be in closed loop and looking up tables according to load/rpm/manifold pressure? If the manifold pressure is lower then it would just look up the figure for that value, thats how i understood it, prob wrong though:) no ecu will be in closed loop at wot it will be in open loop reading off the map table that was mapped at time of mapping. closed loop is for light throttle applications off boost to hold fueling around schiometric 14.7 afr, to help fuel economy. Quote Link to comment Share on other sites More sharing options...
Scott Posted May 30, 2011 Author Share Posted May 30, 2011 lol what exactly has been explained then ? nothing as far as i can see other than map it at full boost and it will sort itself out for everything below it, what else exactly has been explained ? lol You think? You honestly think you explained what was written there? Maybe as you can see it working in your head you think you are explaining it when you write brief responses but I can assure you I didn't follow. Nothing else was really said by the way. It was just put forward in a logical, reasoned response rather than just throwing a couple of words together in each reply. Got there in the end though Quote Link to comment Share on other sites More sharing options...
bigbloodyturbo Posted May 30, 2011 Share Posted May 30, 2011 no ecu will be in closed loop at wot it will be in open loop reading off the map table that was mapped at time of mapping. closed loop is for light throttle applications off boost to hold fueling around schiometric 14.7 afr, to help fuel economy. I got the two mixed up but my understanding of it was sound atleast. Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted May 30, 2011 Share Posted May 30, 2011 You think? You honestly think you explained what was written there? Maybe as you can see it working in your head you think you are explaining it when you write brief responses but I can assure you I didn't follow. Nothing else was really said by the way. It was just put forward in a logical, reasoned response rather than just throwing a couple of words together in each reply. Got there in the end though i guess i am not the best at explaining things, just trying to help though fella Quote Link to comment Share on other sites More sharing options...
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