Flat spot and re-mapping

[Shane_R27]

Yes I know, another flat spot thread. I know this is common and I have searched the forum high and low and just seem to have a mixed view on this.

Right, I bought the car with a K&N panel filter and a Miltek non-res cat back exhaust system. Both cats still in place and to my knowledge still on the standard map. According to the service history the plugs were changed a year ago. The second lambda sensor does need replacing, new NGK one in the car ready to go on. I've held back on fitting it as I actually plan to remove the main cat and do a lambda bypass so it doesn't throw up a light.

I believe the first lambda measures the mixture and alters as necessary, the second just measures effectiveness of the cat so in theory this shouldn't affect running. Correct me if I'm wrong.

It has an aggressive flat spot and splutters and pops in the usual rev range (2.5k to 3k) hot or cold, runs lumpy when cold but goes like stink when it's warm and on song.

So my questions are:
Does this sound like usual behaviour?
If I remove the cat, will it still be flat even after a remap?
If I go for a generic remap, specifically for a decat, do you think it will solve it?
Is it worth the extra time/money to have a custom remap on a dyno?

I'm not chasing horses I just want the power to be crisp and good throttle response. I do like the noise it makes though so don't really want a resonator put in just to make it run better.

I'm after anyone's personal experience or if we have any tuners that can shed some light on it that would be most helpful.

I'm sorry it's a long question but I just need to know which direction to take.

I thank you all in advance

 

[sevenfourate]

All normal stuff i'm afraid. Removing a cat will likely make it worse without remapping.



Custom map all the way. Absolutely. No question.

You've answered your own question by even thinking about what is the best way to go about it......

I've never known anyone disappointed by a true remap (?). Same can't be said of generic jobs. (And my remap is / was one of the best mods to date in terms of everyday drive-ability / smoothness, torque etc). And if it isn't right - it is something you have to live with every single time you drive it. You cant hide or get away from that !!!

"Do it once - do it properly" is my mantra.

 

[Big Ben]

I had mine live mapped on the Dyno at Engine Dynamics. From memory it's not that much more than a generic map but it will leave your car bang on with no flat spots.

For reference I have a toyosports manifold, KTR induction kit and a Scorpion cat back exhaust.

It sounds like you've spent a few quid on the car so my opinion would be to finish all mods then spend a little bit more on getting it mapped on a dyno.

Good luck with whatever you choose

 

[Shane_R27]

All normal stuff i'm afraid. Removing a cat will likely make it worse without remapping.



Custom map all the way. Absolutely. No question.

You've answered your own question by even thinking about what is the best way to go about it......

I've never known anyone disappointed by a true remap (?). Same can't be said of generic jobs. (And my remap is / was one of the best mods to date in terms of everyday drive-ability / smoothness, torque etc). And if it isn't right - it is something you have to live with every single time you drive it. You cant hide or get away from that !!!

"Do it once - do it properly" is my mantra.

Thanks. Kind of what I was thinking but I just need to hear it from people who have been in the same position. I really love the car as a toy but when it comes to driving normally it actually pisses me off a bit because it isn't that kind of car. Thanks again, I think I've made my mind up

 

[Shane_R27]

I had mine live mapped on the Dyno at Engine Dynamics. From memory it's not that much more than a generic map but it will leave your car bang on with no flat spots.

For reference I have a toyosports manifold, KTR induction kit and a Scorpion cat back exhaust.

It sounds like you've spent a few quid on the car so my opinion would be to finish all mods then spend a little bit more on getting it mapped on a dyno.

Good luck with whatever you choose

Thanks. Yes you're right I have spent a bit on the car and I've not even had it a month yet. The more I drive it the more I'm finding. I won't give up on it it's just my original list of things to do is getting pushed further and further back! Mechanical first, cosmetics second.

 

[sevenfourate]

Thanks. Kind of what I was thinking but I just need to hear it from people who have been in the same position. I really love the car as a toy but when it comes to driving normally it actually pisses me off a bit because it isn't that kind of car. Thanks again, I think I've made my mind up

Transformed my car from the crappo standard fuelling into something thats a pleasure to drive.

Not masses of bhp added. Just plenty of real World extra drive, throttle response and a lack of cold Kangarooing !

I had mine done at Engine Dynamics like Ben above. But any of the big-boys such as ED, EFi, RS Tuning will sort you out.

 

[Shane_R27]

Transformed my car from the crappo standard fuelling into something thats a pleasure to drive.

Not masses of bhp added. Just plenty of real World extra drive, throttle response and a lack of cold Kangarooing !

I had mine done at Engine Dynamics like Ben above. But any of the big-boys such as ED, EFi, RS Tuning will sort you out.

This sounds like just the ticket. Thanks for sharing.