NA 1.6 - Top end zing
Discussion
Possibly a dangerous path this but I'll ask anyway.
Car is 93 1.6 NA. Pretty much standard other than an unknown brand back box.
I am not chasing more power particularly. That's a game with no end and I like the fact the car can be thrashed mercilessly within broadly legal boundaries. I also do not want to jeopardise reliability as the turn key, go anywhere nature of the MX-5 is one of the biggest appeals.
But, what I don't love is that the engine builds power progressively to about 6k ish but then seems a bit lazy and a little coarse after that to the redline. I'm kind of hoping there might be some little tweaks I can do that keep the power building smoothly through to the limiter. I generally love revvy, free spinning engines that just seem to beg to be thrashed.
Thoughts so far are along the lines of a lightened flywheel and possibly moving away from the AFM to a cold air induction set up. The latter one, only because I have read in a couple of places that the AFM is the weakest link at higher revs. I don't want to go too far with this but I would consider head work if there were little gains to be made but I'd be reluctant to go to an aftermarket ECU.
I also think my aged engine mounts might not be helping with how coarse the engine feels at higher revs so they need to be replaced too.
Car is 93 1.6 NA. Pretty much standard other than an unknown brand back box.
I am not chasing more power particularly. That's a game with no end and I like the fact the car can be thrashed mercilessly within broadly legal boundaries. I also do not want to jeopardise reliability as the turn key, go anywhere nature of the MX-5 is one of the biggest appeals.
But, what I don't love is that the engine builds power progressively to about 6k ish but then seems a bit lazy and a little coarse after that to the redline. I'm kind of hoping there might be some little tweaks I can do that keep the power building smoothly through to the limiter. I generally love revvy, free spinning engines that just seem to beg to be thrashed.
Thoughts so far are along the lines of a lightened flywheel and possibly moving away from the AFM to a cold air induction set up. The latter one, only because I have read in a couple of places that the AFM is the weakest link at higher revs. I don't want to go too far with this but I would consider head work if there were little gains to be made but I'd be reluctant to go to an aftermarket ECU.
I also think my aged engine mounts might not be helping with how coarse the engine feels at higher revs so they need to be replaced too.
Gad-Westy said:
Possibly a dangerous path this but I'll ask anyway.
Car is 93 1.6 NA. Pretty much standard other than an unknown brand back box.
I am not chasing more power particularly. That's a game with no end and I like the fact the car can be thrashed mercilessly within broadly legal boundaries. I also do not want to jeopardise reliability as the turn key, go anywhere nature of the MX-5 is one of the biggest appeals.
But, what I don't love is that the engine builds power progressively to about 6k ish but then seems a bit lazy and a little coarse after that to the redline. I'm kind of hoping there might be some little tweaks I can do that keep the power building smoothly through to the limiter. I generally love revvy, free spinning engines that just seem to beg to be thrashed.
Thoughts so far are along the lines of a lightened flywheel and possibly moving away from the AFM to a cold air induction set up. The latter one, only because I have read in a couple of places that the AFM is the weakest link at higher revs. I don't want to go too far with this but I would consider head work if there were little gains to be made but I'd be reluctant to go to an aftermarket ECU.
I also think my aged engine mounts might not be helping with how coarse the engine feels at higher revs so they need to be replaced too.
Clean the TBCar is 93 1.6 NA. Pretty much standard other than an unknown brand back box.
I am not chasing more power particularly. That's a game with no end and I like the fact the car can be thrashed mercilessly within broadly legal boundaries. I also do not want to jeopardise reliability as the turn key, go anywhere nature of the MX-5 is one of the biggest appeals.
But, what I don't love is that the engine builds power progressively to about 6k ish but then seems a bit lazy and a little coarse after that to the redline. I'm kind of hoping there might be some little tweaks I can do that keep the power building smoothly through to the limiter. I generally love revvy, free spinning engines that just seem to beg to be thrashed.
Thoughts so far are along the lines of a lightened flywheel and possibly moving away from the AFM to a cold air induction set up. The latter one, only because I have read in a couple of places that the AFM is the weakest link at higher revs. I don't want to go too far with this but I would consider head work if there were little gains to be made but I'd be reluctant to go to an aftermarket ECU.
I also think my aged engine mounts might not be helping with how coarse the engine feels at higher revs so they need to be replaced too.
RustyMX5 said:
A bit extreme but I had a mk2.5 1.8 block dropped in mine with a lightened flywheel. That was quite a bit better. I found that the original 1.6 engine in the NA to be enjoyable but a little lacklustre above about 6000 rpm too.
Cheers. I’d considered it but maybe not the sort of thing I want to get into for now. 1600’s respond well to a head skim and reground cams.
I ran a track car with a 30 thou head skim,a pair of Piper 270 cams,JR exhaust manifold,AK automotive exhaust and a JR cold air intake.Standard ecu and AFM.
The cams drop straight in without need for verniers and coupled with the head skim really livened up the top end. Instead of flattening out at 6k it just kept pulling all the way to the 7250 limit,great fun.
It was totally reliable and you could beat on it lap after lap without worry of it melting itself,I always ended up giving in before it did!
If you’re reasonably competent with spanners it’s not a difficult thing to do and I would suggest you’d be able to carry out the work for under a grand including water pump, timing belt, genuine head gasket and cam seals,etc.
I never had the car on a dyno but would guesstimate somewhere around 135 to 140 bhp.
I ran a track car with a 30 thou head skim,a pair of Piper 270 cams,JR exhaust manifold,AK automotive exhaust and a JR cold air intake.Standard ecu and AFM.
The cams drop straight in without need for verniers and coupled with the head skim really livened up the top end. Instead of flattening out at 6k it just kept pulling all the way to the 7250 limit,great fun.
It was totally reliable and you could beat on it lap after lap without worry of it melting itself,I always ended up giving in before it did!
If you’re reasonably competent with spanners it’s not a difficult thing to do and I would suggest you’d be able to carry out the work for under a grand including water pump, timing belt, genuine head gasket and cam seals,etc.
I never had the car on a dyno but would guesstimate somewhere around 135 to 140 bhp.
Belle427 said:
It's a common issue on the 1.6 engines, I'd maybe look at a set of cams that can iron that out but is is a slippery slope!
Have a look at the Bofi racing website.
Have a look at the Bofi racing website.
Cardo said:
1600’s respond well to a head skim and reground cams.
I ran a track car with a 30 thou head skim,a pair of Piper 270 cams,JR exhaust manifold,AK automotive exhaust and a JR cold air intake.Standard ecu and AFM.
The cams drop straight in without need for verniers and coupled with the head skim really livened up the top end. Instead of flattening out at 6k it just kept pulling all the way to the 7250 limit,great fun.
It was totally reliable and you could beat on it lap after lap without worry of it melting itself,I always ended up giving in before it did!
If you’re reasonably competent with spanners it’s not a difficult thing to do and I would suggest you’d be able to carry out the work for under a grand including water pump, timing belt, genuine head gasket and cam seals,etc.
I never had the car on a dyno but would guesstimate somewhere around 135 to 140 bhp.
Thanks both. I quite the like the sound of this sort of option. I'm handy with the spanners but head skimming not so much! But I'm sure I could find somewhere to do that sort of work. I actually like the idea of doing this at my leisure on a spare engine and taking my time to check over everything else at the same time. How much noise does a typical aftermarket manifold add and how important is it in this recipe? Trying to maintain civility and keep costs in control a little. I ran a track car with a 30 thou head skim,a pair of Piper 270 cams,JR exhaust manifold,AK automotive exhaust and a JR cold air intake.Standard ecu and AFM.
The cams drop straight in without need for verniers and coupled with the head skim really livened up the top end. Instead of flattening out at 6k it just kept pulling all the way to the 7250 limit,great fun.
It was totally reliable and you could beat on it lap after lap without worry of it melting itself,I always ended up giving in before it did!
If you’re reasonably competent with spanners it’s not a difficult thing to do and I would suggest you’d be able to carry out the work for under a grand including water pump, timing belt, genuine head gasket and cam seals,etc.
I never had the car on a dyno but would guesstimate somewhere around 135 to 140 bhp.
An aftermarket manifold won’t make a huge difference to noise but if you’re on a budget you could replicate the mods that the Mazda cup racers use on standard manifolds. Basically involves welding up the internal joints at the factory collector then smoothing out the welds for better flow. Costs nothing but time! The cup cars tend to make 130bhp on standard cams with a head skim,3 angle valve seats and tweaked AFM to lean out the top end.You would basically be replicating that spec with a pair of cams added. I know Blink motorsport used to offer the AFM mods but I’m not sure who you would go to now…try getting in touch with some of the current teams? Or AK Automotive maybe?
A decent local engine machine shop will skim the head for you for a reasonable sum and Piper will regrind your existing cams. The 270’s idle like standard and have no adverse effect to the low down (non existent
)torque.
If you pick up a spare head and cams it would be a nice little project to do a bit at a time before swapping it for the standard one.
A decent local engine machine shop will skim the head for you for a reasonable sum and Piper will regrind your existing cams. The 270’s idle like standard and have no adverse effect to the low down (non existent
)torque.If you pick up a spare head and cams it would be a nice little project to do a bit at a time before swapping it for the standard one.
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