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Discussion Starter · #1 ·
What about fitting a boost controller to limit boost at certain gears and more importantly RPM?

The torque wave of a stage 2 or even hybrid car is lowering at around 4.5-5k RPM. If you set the BC up to provide max boost at this RPM then you'll still get the power top end but bypass the rod bending torque surge low down. Should make the car feel good aswell having the extara power kicking in.

Discuss..
 

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MJ,

As far as I know you do not need a boostcontroler. The standard ECU that comes with the megane is capable of doing most of these things you mention.
Get in contact with a good renault tuner (for remaps that is).

Possibilities that I know of.
- max boost/pressure limitation (not sure if you can adjust these related to RPM)
- calculated torque generated limitation in first gear (may be other gears as well)

I have been thinking the same as you. Why not limit the torque to say 280 or 300lbft from 2500-3000rpm so you have a near horizontal and thus steady torque curve/power delivery al the way to around 5000rpm.
 

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The car on a standard turbo isn't capable of generating 300ft.lb much over 4.5k, so you may as well run a stage 1 map if you are going to boost limit lower in the rev range.
 

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What about fitting a boost controller to limit boost at certain gears and more importantly RPM?

The torque wave of a stage 2 or even hybrid car is lowering at around 4.5-5k RPM. If you set the BC up to provide max boost at this RPM then you'll still get the power top end but bypass the rod bending torque surge low down. Should make the car feel good aswell having the extara power kicking in.

Discuss..
What about using a boost controller called a 'throttle' connected to that big ECU in the bonce.
 

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What about using a boost controller called a 'throttle' connected to that big ECU in the bonce.
That I find a bit too simple thought of Conley.

Disregarding warrenty:
What if Renault standard mapped the car outside it's safety operation limits...and told you to feather the throttle because else you might eventually damage the engine.
I know what you and any other person would have told Renault then.
 

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That I find a bit too simple thought of Conley.

Disregarding warrenty:
What if Renault standard mapped the car outside it's safety operation limits...and told you to feather the throttle because else you might eventually damage the engine.
I know what you and any other person would have told Renault then.
I think that's the point though is us who are operating the car outside its safely limits not Renault who have already defined those limits. my view on it is if you feel the need to go above stage 2 you need to look at weather you need to start uprating engine components not just limiting torque.
if limiting torque is what you believe will increase the lifespan of the car the surly stay at stage 1 as the figures are not a million miles apart and must carry less of a risk.
 

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Discussion Starter · #10 ·
Nice one Lee. What's your plans for it?

Just pay for a custom map. Job done.
I intend to soon but keeping boost at 1.2 bar. That's what prompted the question. AFAIK no one has ran all the stg2 mods (aswell as an intake and injectors) but kept boost at 1.2 bar so I don't know what power and torque I'll be looking at. Looking at Lee's graphs with his stg2+ injectors he was pushing 286bhp where as his stg2 was only 254.8. I'm running more than that on a stage 1 map but 5bhp or so is neither here nor there. Anyway my point - It's totally unknown. The injectors on Lee's car made him an extra 30bhp. How much can they help on a car boosting at 1.2 bar? The outcome of that will help with my next move.

I'm looking to increase the top end power not low down torque. As you've said many times Conley, It means nothing when your canning it around the track and your keeping the engine on song. Ok a fatter midrange will help on the road or on the odd ocasion on track where it's better to take a higher gear through a corner but for this argument I'll keep things simple and talk top end.

As for feeding in the power in low down, Behave!!! ;) Something takes off or you need to get a move on your going to use the power if it's there not worry about If you'll fook the engine.

The car on a standard turbo isn't capable of generating 300ft.lb much over 4.5k, so you may as well run a stage 1 map if you are going to boost limit lower in the rev range.
Not really B. The majority of cars seem to be letting go low down the revs. Stg 2 torque peaks around 3-4k RPM, After this it drops rapidly. If you run 1.2 bar up untill 4.5-5k then let the boost controller crank it up to 1.4 bar for the top end BHP gains thus not seeing any of the unwanted torque. Lee's stg2 + injectors was making almost 280bhp by 4.5k RPM compared to just over 250 with his normal stg2. Saying that it is only .2 bar increase and I'm assuming on a custom stg 1 map the BHP increase won't be all that great - I could be wrong though and in that case yes, It would only make sense on a hybrid car.

I don't think you can limit the boost by gear or RPM on the meg ECU Feelx but yes. That's what I'm thinking anyway.

Lee's power graphs for anyone that's interested - http://www.meganesport.net/community/showthread.php?46217-stage-2-yesterday/page5&highlight=cams
 

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Surely to god MJ you must know the answer to your own question from the amount you must of read on here, of course it the torque , a standard internal engine won't take high torque figures for long, you know that.
 

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Basicly MJ you sugest that the standard 225 turbo can boost up to 1.4 bar @ 4500 untill higher rpm.
Or is the 1.4 bar needed to produces the 360lbft torque at 3k-4k rpm. I always assumed that the standard turbo boost tailed off after 4500rpm.
Do you have a powergraph including boost of a stage 2+?

Just me being interested, how much work is involved with fitting a boostcontroler? And what about the costs?
 

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Discussion Starter · #13 · (Edited)
Surely to god MJ you must know the answer to your own question from the amount you must of read on here, of course it the torque , a standard internal engine won't take high torque figures for long, you know that.
Correct A16 but since nothing has been tested properly we can only assume from what we have found and most recently that has been a rod shaped like a bananna = too much torque.

Yes Feelx. For example - Have the car boosting at 1.2 bar from 0-4k or even 4.5k RPM then at 4 (or 4.5k RPM) have it boosting to 1.4 bar to reach bigger BHP. The standard turbo does start to drop torque at 4k RPM but it can still keep making power If you go for bigger injectors + an intake along with other mods.

I'm going to see what the car will make with all the mods (injectors, intake, FMIC, decat, recirc, actuator) running 1.2 bar for all the rev range first. As I said before no one seems to of tried this before. Most seem to go stage 2 on the standard injectors and then wonder why the car is only making 260-265 BHP but **** loads of torque.

You can see some power graphs here - http://www.meganesport.net/community/showthread.php?46217-stage-2-yesterday/page5&highlight=cams

I stated the injectors made an extra 30bhp in my other post. My mistake. I was looking at the wrong power. It's about an extra 10bhp and holds power better.
 

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MJ
Firstly I've bought the boost controller to suit the engine bits I've ordered & also the turbo I'll soon be ordering.
Secondly the 256 graph is stage 1 the 276 is stage 2
Stage 3 makes roughly 1.2 bar upto 4500 rpm then drops to 0.8bar to the limiter.
:):):):)
Thanks lee
 

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Discussion Starter · #15 ·
MJ
Firstly I've bought the boost controller to suit the engine bits I've ordered & also the turbo I'll soon be ordering.
Secondly the 256 graph is stage 1 the 276 is stage 2
Stage 3 makes roughly 1.2 bar upto 4500 rpm then drops to 0.8bar to the limiter.
:):):):)
Thanks lee
I did notice when I had another look at the graphs. I thought 30bhp seemed abit high! I thought you may be turning the boost on te hybrid aswell :sweatdrop:

Does the hybrid run at 1.2 bar normally? I thought I read somewhere it was 0.8 bar. That's why I was wondering how would a hybrid car drive low down on a boost controller but If it needs 1.2 bar to reach 300bhp then a lower boost up to 4k RPM or so could be an option.
 

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No the 1.2 bar early on is to get the torque up. If it stayed at 1.2 all the way through the rev range it would be making about 330 bhp. The boost is backed off to 0.8 bar up top to keep the bhp down
 

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Discussion Starter · #17 ·
Ah, I see. Did you do a run of it at a constant 0.8 bar. What was peak torque? Can the ECU adjust boost by RPM then If your's starts at 1.2 bar then drops down to 0.8?
 
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