the old favourite - super charges & Turbos but....

[steve bowen]

One simple question, mx5s with their lack of grip do they really suit lots of power low down in the rev range, so are small turbos and superchargers really suitable for the car?

I've heard hundreds of stories of people loosing them out of roundabouts as the power just can't be put down etc. Infact what prompted this question is last night I took a chap out in my car, his car has a jackson racing supercharger, chargecooler, MoTec management etc produces 180bhp and he said he couldn't imagine the car with more power as the backend is all over the place when you don't want it to be when your pootling around as theres to much low down power. My car on the other hand has 250bhp from a big relatively laggy turbo, theres not much power there until 4500rpm then you have over 200bhp for the rest of the rev range. This means pootling about as you normally would not reving the car its tame as a little lamb, but bury the throttle and it goes like hell, but as its over 4000rpm your already rolling so getting the power down isn't as hard, suddenly after a ride in my car he's coming round to the idea maybe a bit of lag is no bad thing.

What are people opinions?

[MX-5 Lazza]

Hi Steve

My car has an MP62 SC and plenty of torque at low, mid & high revs (150lb/ft from about 2500 to redline with a peak of 170lb/ft - should be more once the exhaust & fuelling is finally sorted). The power is there all the time as if I'd fitted a bigger engine instead of forced induction.
I never have any traction problems either accelerating or cornering. I mean yes I can burn out the tyres if I really want to but then you can do that without FI.

My car is a Mk2.5 Sport so has the Torsen LSD and Goodyear F1 GSD3 195 profile on my track wheels and 205 profile on my road wheels.

[anonymous-user]

Steve's friend's foot, yesterday:

[steve bowen]

Could well be

Its just such a regular comment, even on a little club run just between dyno and pub, someone following me commented they had a little "moment" exiting a roundabout, their car was about 60bhp down on me yet i had no such issues.

[MX-5 Lazza]

I've followed people on drives where they were clearly only just holding on to the back end whereas I was just pootling around barely even trying...

Probably a combination of:
> Driving style
> Poor alignment
> Tyre type
> Tyre condition/pressure

[steve bowen]

Maybe its as simple as that.

I've not driven a supercharged mx5 but I can understand how having a lot of power say by 2750rpm could be a pain in that morning half asleep drive to work in the depths of winter when you push the pedal to leave the roundabout, .. and well we hear the rest regularly. Quite possibly is just poorly setup cars & driving style.

[MX-5 Lazza]

MX-5 Lazza said:

I've followed people on drives where they were clearly only just holding on to the back end whereas I was just pootling around barely even trying...

Probably a combination of:
> Driving style
> Poor alignment
> Tyre type
> Tyre condition/pressure

I forgot the most important one...
> Limited Slip Diff'

[MX-5 Lazza]

steve bowen said:

Maybe its as simple as that.

I've not driven a supercharged mx5 but I can understand how having a lot of power say by 2750rpm could be a pain in that morning half asleep drive to work in the depths of winter when you push the pedal to leave the roundabout, .. and well we hear the rest regularly. Quite possibly is just poorly setup cars & driving style.

Tell you what Steve; next time we get together I'll let you have a drive of my car and you'll see just how easy it is to drive a supercharged car, slow or fast. there is no reason at all that an SC car should catch anyone out on a roundabout.

[Firestar_3x]

Sounds like someone needs to learn now to drive a RWD car.

Any RWD car will catch you out on a corner or roundabout if you do something silly, regardless of how much power it has.

Mine drives no diff from when it was standard.

[redgriff500]

MX-5 Lazza said:

I forgot the most important one...
> Limited Slip Diff'

Actually the LSD makes you MORE likely to throw the back out and have a moment.

That is exactly why I fitted mine (I can that fun) and they are good for good drivers but a complete liability for poor ones.

[Matt230]

I have a superacharged 5 similar spec to Lazza's and would agree that even driven enthusiastically grip is mostly available. I would put it down to poor alignment and a misunderstanding of weight transfer or RWD dynamics if suffering with traction that badly

Matt

[Firestar_3x]

Or really pants tyres!

[phatmanace]

hmm, with my turbo, I can definatley slide the back round if I want to... but then I could before I had the turbo fitted.

I think that the problem is that not that many people have RWD cars as their first couple of cars that they own. folks tend to go up through hot hatches. Certainly this is the first one that I have owned. I was used to FWD cars and being able to hoon it round bends, round abouts or slip roads and it just stuck. Fact is: you can't do that in a RWD

after 2 walshy days, I've learned a little about how to feel when my car is going to slide and how to control it. it has made me hugley more respectful when driving around, esp in the wet.

basic mantra for me, is that I don't nail it, unless I'm pointing straight forwards!!

-Ace

[tybo]

Since mine's been supercharged, i've found traction has really improved over standard!!

Pre SC, in the wet, you could have the back end out on every corner without trying.

Just seems a lot more predictable now...don't know why.

Edited by tybo on Monday 9th July 21:33

[MX-5 Lazza]

My car history:

Vauxhall Viva: RWD
Ford Cortina MkIII: RWD
Rover P6 2000 SC: RWD
Vauxhall Chevette: RWD
Rover P6 2000 TC: RWD
Ford Cortina MkIII: RWD
Rover P6 2200 TC: RWD
Rover 216: FWD
Toyota Carina: FWD
Mazda MX-5 Mk1: RWD

Currently
Mazda MX-5 Mk2.5 (supercharged): RWD
Ford Focus 1.8 Zetec: FWD

So yes, I do have a fair bit of RWD experience and know how to control the rear grip and general attitude using the throttle. The thing is the grip levels of my current car are way higher than anything else I've ever owned (except possibly the Focus - no really, it has great grip just not the handling of the MX-5) so the speeds have to be that much higher to require any throttle corretion unless it's very wet or cold.

The motorbike experience in the early years probably helps understand grip levels and how it's affected by road surface changes too.

Edited by MX-5 Lazza on Monday 9th July 22:14

[skinny]

i know what you mean about the focus laz - had one last week and if you're sensitive with weight transfer, the thing really does grip, and handling not too bad either