Safe Remap Linits

[Gaz205 50]

Car - Hyundai Ix35 2.0 4wd

Economy map 134bhp to 161 bhp, 236 lbft to 272lb ft

Stage one map 134 bhp to 175 bhp, 236 lbft to 305 lb ft

 

I'm chasing economy and improved drive ability as the car struggles with early gear changes that I'm confident similar powered cars cope with. Gearing isn't really an issue as the rpm is around 1500 with not much pull

 

What is a safe % increase? Is torque more of a worry than bhp? The stage one is around a 30% increase, the economy is just under 20%.

 

Clutches aside, what kind of tolerances are worked into the gearbox, diffs, and prop shafts etc? Does any one really know?

 

Out of my depth with modifying diesels, especially crossover 4x4's!

Cheers

Gaz

[welshpug 1,657]

just don't change gear too early?

 

 

 

there's many reasons why they don't make power under 1500, namely that the turbo is on a small capacity engine and wont make enough air flow to go with more fuel!!

 

vibrations, chucking lots of fuel in at low rpm creates lots of harsh vibrations, these can wear out a multitude of components, clutches flywheels crankshaft pulleys, alternators, most modern vehicles have clutched alternator pulleys because of these vibrations.

 

 

these vibrations don't tend to get carried down the drivetrains due to the efforts put into the design of the flywheels engine mounts and ancillaries, its more torque that can wear out/damage those components from running outside their design specifications.


Mild mapping can reap benefits of the safety margins built into the designs, how much you gain depends how well designed and conservative the manufacturers have been.

[welshpug 1,657]

just had a brief look, I'm not surprised a 1700 kg vehicle is a little sluggish with only a 2.0 engine if you out your foot down below boost threshold

 

 

I've driven a borrowed saab 9-3 this week, its a surprising 1600 kilos and 147 bhp 1.9, that too has no guts whatsoever under 1500.

[Gaz205 50]

I think the 1500 is the exaggerated rpm, a change say 3rd to 4th at around 3000 rpm drops the car to around 1500-1800 rpm, it doesn't labour the engine (no vibrations) and the bus begins very gradually to pull. It really feels like it needs an extra 10%.

I've experience similar in many small capacity charged petrols but my main concern is basically how much can the standard components take? Engine aside

[Anthony 1,003]

Really depends on the individual model - a Hyundai forum would probably be a better place to ask about weak points.

 

Generally speaking, the weakest point is usually the clutch, and it's not uncommon for an ageing worn clutch that was coping with a standard tune to be pushed over the edge and slip when asked to deal with 30% odd more torque.

 

Most cars will typically take a stage 1 tune without any issues if everything is in good order, although clearly any parts that are already on their last legs may cry enough if you start asking 30% more power from them.

[Gaz205 50]

I did try a Hyundai forum but with the type of car there wasn't many results. The caravan towers rave about chip boxes - not a chance I say!!

 

If it were 2wd I wouldn't worry, it's the diff and prop shaft set up that worries me as its only a soft roader so how much was engineered into them?

There is a higher power variant of this car (184 bhp and similar lbft to what the stage 1 tune would achieve) but it runs an auto box only, again making me worry the manual box has a lower explosion limit.

I have made my mind up regardless to trial the economy map with very sensible expectations. I will put a line on later with my results.

Thanks for your inputs!

Gaz

Edited November 2, 2016 by Gaz205

[welshpug 1,657]

it depends massively on how well the map is written, as with any map.

 

dcc has a stage 1.5 map on his 9-3 TiD 150, pushing around 185 bhp, due to the way the fuel and boost has been dumped in straight at 2200 it made a year old genuine clutch start slipping!

 

we did find out the 185 bhp ttid variant has a different clutch and flywheel, so a smoother transition from off boost to something like 2.5 bar is needed!!

[Gaz205 50]

it depends massively on how well the map is written, as with any map.

 

dcc has a stage 1.5 map on his 9-3 TiD 150, pushing around 185 bhp, due to the way the fuel and boost has been dumped in straight at 2200 it made a year old genuine clutch start slipping!

 

we did find out the 185 bhp ttid variant has a different clutch and flywheel, so a smoother transition from off boost to something like 2.5 bar is needed!!

Absolutely! I do trust the agent for the map... He has it now so let's see how well it responds. It's more mpg and like I mentioned drive ability I'm after. The ability to tow is a future requirement aswell now I've had a tow bar fitted so load lugging up hills should be good as it has a 2000kg limit

[Gaz205 50]

Does anyone know any good clutch specialists? ????????

[dcc 855]

Haha

 

What map did you go for?

[Gaz205 50]

Economy map, the guy said straight away he's noticed clutch slip. 52k 5 1/2 year old car. Bit premature I think, clearly aggravated by this but that's the risk I guess!

[dcc 855]

Tell him to put old map back on tbh, get clutch done and then go back for rest of map.

 

The problem tends to be how the torque is applied with remaps, too much too quick (like my saab), its 310ftlb and 196bhp, it comes in too hard imho.

 

Good luck

[Gaz205 50]

Tell him to put old map back on tbh, get clutch done and then go back for rest of map.

 

The problem tends to be how the torque is applied with remaps, too much too quick (like my saab), its 310ftlb and 196bhp, it comes in too hard imho.

 

Good luck

I've actually left it on, there is no surge to be honest, as it's the economy map the slip comes at peak torque it feels, around 3k and it pulls through it. No massive feeling of more power, 4th 5th and 6th feels very strong, and it's eradicated the lack of enthusiasm at each gear change - at the sacrifice of the slippy clutch. The map company wanted to charge him twice for the map so to be fair to him I left it on as they said it's not a faulty map.

An oem clutch is looking around 350-400.

It's the Mrs car so.....

God knows how it would've coped with the stage 1 at over 300lb ft!!

Is your Saab the one with the GM motor?

[dcc 855]

Yes, the z19dth 16v diesel.

 

Lots of problems with them generally, much down to egr, dpf and the inlet swirl flaps.

 

Next step for mine is a new inlet manifold and egr removal! The dpf is long gone!