How easy is an SP replica?

[bootz]

Maybe Bigdog or others can confirm this:

Driving through a standard 6-speed 'box and 3.64:1 Torsen LSD, the 1119 kilogram SP Turbo offered - not surprisingly - awesome straight-line performance. 0 - 100 km/h sprints took mid 6-seconds and the quarter mile a scant 14.6-seconds.


Does that mean my '02 also has a Torsen LSD that I didn't know about?

[AJ]

SP's did NOT have an LSD from the factory.

[Locutus]

I am not interested in thrashing my car on the track. What I need is to get safely away from that 2 tonne Jeep Cherokee crowding my arse on the highway and the 5's accelleration does not inspire me with confidence.

sorry, but if you can't pull away from a cherokee in an MX5, either you're driving it wrong or something is wrong with your car.

[bootz]

I am not interested in thrashing my car on the track. What I need is to get safely away from that 2 tonne Jeep Cherokee crowding my arse on the highway and the 5's accelleration does not inspire me with confidence.

sorry, but if you can't pull away from a cherokee in an MX5, either you're driving it wrong or something is wrong with your car.

How the flower can you say that?
The Cherokee is packing a guzzling 3.0 turbo diesel V6, with wait for it 510nm torque. No matter how it stacks up, in traffic the MX-5 acceleration is going to be outclassed.

I just used the Jeep as one example. It is just as embarrassing being blown away by a Polo GTI.

[Locutus]

How the flower can you say that?
The Cherokee is packing a guzzling 3.0 turbo diesel V6, with wait for it 510nm torque. No matter how it stacks up, in traffic the MX-5 acceleration is going to be outclassed.

I just used the Jeep as one example. It is just as embarrassing being blown away by a Polo GTI.

for acceleration, power is more important than torque.
http://autospeed.com/A_108648/cms/article.html

2010 cherokee 3.7L V6
151kw, 1935kg = 78kw/tonne

2002 mx5 1.8L I4
102kw, 1085kg = 94kw/tonne (20% more)


no, a standard mx5 is not a fast car in a straight line by any stretch of the imagination - and yes, it will lose the traffic light grand prix to most current hot hatches.


to bring this back on topic, if you want an SP, sell your car and buy an SP. there is a very nice example for sale in this forum this very moment for a good price. by the time you get your car up to SP levels of power and driveability you will easily have a $10k hole in your pocket. as far as i know, tuning the VVT engine can't done on the cheap.

[bootz]

Good article, it makes the point I wanted to make:

* for best acceleration, maximise power
* for best driveability, a high torque, non-peaky engine is better

" An engine with high torque throughout the rev range will have good low-rev and part throttle response; this is the reason that cars like 4.1-litre Cortinas feel that they are very quick, even though they are not in absolute terms. That 4.1 has a very flat torque curve, with a maximum torque similar to the Commodore Ecotec V6 - but I know which engine I would prefer in outright acceleration terms (the V6 has about 50% more power)!"

This is why the VW cabrio is so nice to drive and also why the SP is so good with its nice fat torque delivery.

[Locutus]

yep, that's why your VW feels faster. no doubt, it has a more flexible engine for city driving.

keep in mind that although the SP has a nice torque curve it doesn't pull hard from down low. the turbo starts to spool at around 2300rpm, so you don't get a proper a kick in the pants until 3000rpm+. in the city, this means you still need to drop a gear or two for overtaking.

have you considered a supercharger setup? there are a few guys thinking about a group buy of FFS kits.

[bigdog]

One of the older SP contributors on here recorded a 13.8 sec ET at WSID on 17 rims and no name tyres, only the $5 hose mod and a Guru LSD on the car, same as mine, and pulled 150rwkw on the dyno. Dave (my brother) has also done a 13.8, but his car has been tweaked with boost control and ecu. They are quick cars straight out of the box, but suffer from lack of grip on the drag strip. No LSD standard on SPs, many owners have fitted them though.

[bigdog]

On the subject of overtaking, I rarely have to drop a gear. On the M4 at 100kmh 6th is just fine for passing, and I climb most steep hills without downshifting too much, these are torquey cars.

[MX5-SP]

.... only the $5 hose mod ...

Bloody Hell! It seems like only yesterday that mod cost $2.50.... I guess that's inflation for you.

[Locutus]

yeah the lack of LSD as standard in an SP is a small annoyance, but easily fixed.

agree that they are brilliant at highway speeds (90km/h+). been to newcastle and back a few times with a fully loaded car + passenger and have never needed to drop out of 6th on the F3.

i guess it depends on your driving style in the city. unless you cruise at 60km/h in 4th, you will need drop into 3rd or 4th for a brisk overtake.

[bootz]

One of the older SP contributors on here recorded a 13.8 sec ET at WSID on 17 rims and no name tyres, only the $5 hose mod and a Guru LSD on the car, same as mine, and pulled 150rwkw on the dyno. Dave (my brother) has also done a 13.8, but his car has been tweaked with boost control and ecu. They are quick cars straight out of the box, but suffer from lack of grip on the drag strip. No LSD standard on SPs, many owners have fitted them though.

That is FREAKIN' fast. Wow, Bigdog what Guru do you have, guessing 3.9?

On the topic of drivability, forumites tend to say putting an LSD in the mx5 is the best thing since sliced bread, so what does everyone think about this? Looks good to me. (I don't believe it is from an Aust model, prob Jap? Unfortunately sold.)

SE Diff conversion 4.1 ratio....it's a SE set up so it has the Bosch Torsen, heavy duty axles and tail shaft.
Will fit any model NA or NB MX5....it's all the bits you neeed..
Dont miss out these dont come up often ..

$1500

[Benny]

I've got a Guru in my SP, and it would probably cost you a little over $2K to buy and get fitted.
Don't try and fit it yourself, as diffs are quite specialised items to install and set up properly and the whole lot has to be dissassembled to install.

My SP has bags of torque even just off idle - thanks to Daniel!
I reckon mine would run in the very low 13's, or even maybe high 12's compared to some of the cars I've come up against.
Mine put out 183RWkW at the last dyno day, so it is a bit healthier than most.

Once you drive an SP, nothing else even comes close.
What do you think Bad Bong?

[davekmoore]

must....keep...fingers...under......control

Would this be anything to do with the other factory turbo version whose name we shall not mention?

[MX5-SP]

must....keep...fingers...under......control

Would this be anything to do with the other factory turbo version whose name we shall not mention?

Nah!.... It's just AJ's way of getting himself excited.