186bhp@wheels and the wee Eunos handles it fine

186bhp@wheels and the wee Eunos handles it fine

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steve bowen

Original Poster:

1,268 posts

226 months

Sunday 1st April 2007
quotequote all
Just had a day of B & unclassified blatting in the Eunos that returned to me from tuning where it produced 186bhp@the wheels, so about 210bhp at the fly.

The car handles it easily, got to say the chassis doesn't even feel slightly stretched. If anything the increase in torque means it actually feels more planted

RedCabbage

3,606 posts

234 months

Sunday 1st April 2007
quotequote all
Better than your MR2 Turbo?

steve bowen

Original Poster:

1,268 posts

226 months

Sunday 1st April 2007
quotequote all
far more confident booting it throught the bends than in the MR2, the MR2 demanded a lot of respect when "making time" the Eunos is more Kart like just throw it in a corner and you know you'll be fine regardless if the backs twitching.

phatmanace

670 posts

211 months

Monday 2nd April 2007
quotequote all
That's really interesting.

I'm thinking of swapping my stock 1.6 mx5 for an MR2 turbo - as it's much cheaper that upgrading the mx [was gonna do a turbo and get the suspension done]. do you think that's an error?

my other car's a golf 1.8T gti and I always feel safer on a bend in that that in the mx5 which seems to bounce more round the road - this is one of the other reasons I was thinking of swapping it for an MR2

as well as the power increase - have you changed the suspension on your '5?

Cheers
-ace

steve bowen

Original Poster:

1,268 posts

226 months

Monday 2nd April 2007
quotequote all
yes, its got AGX adjustable dampers & Eibach springs.

Don't get me wrong, the MR2's are good and I always got it round tracks pleasingly fast but it was never as confident on the road as the MX5, my MR2 had H&R adjustable coilovers with topmounts and lightweight 16" RAYS wheels so it was better than standard as well.

phatmanace

670 posts

211 months

Monday 2nd April 2007
quotequote all
( at the risk of over analysing my decision! )

what made you swap from mr2 to mx5?

also was it a T-Bar? (Curious how T-bar with the panels off compares with top off mx5!)

steve bowen

Original Poster:

1,268 posts

226 months

Tuesday 3rd April 2007
quotequote all
No I didn't have a T-Bar, I can't stand the look of them I think they spoil the lines of the car and look very 70's also the buffeting at anything over 50mph is absurb, it's worse at 50mph than at 110mph in the mx5.

I just got tired of the MR2, was the most unreliable car i've ever owned. I suppose its really just down to its age, mine was a 1992 rev2 so 14 years old when I sold it.

I'd have another, but only a 1994 or younger GT-S Tin Top and i'd need to do about £5K's worth of mods and refreshing the day I got it.

phatmanace

670 posts

211 months

Wednesday 4th April 2007
quotequote all
ok - you've convinced me - I think i'm gonna get my mx5 turbo'd instead of the MR2

:-)

-a

iaint

10,040 posts

240 months

Wednesday 4th April 2007
quotequote all
steve bowen said:
Just had a day of B & unclassified blatting in the Eunos that returned to me from tuning where it produced 186bhp@the wheels, so about 210bhp at the fly.


The fly estimate seems a little pessimistic to me. I'd expect there to be more like 40bhp+ lost in transmission and tyres. As a general rule of thumb the rx-7 loses about 18% or 55bhp (both numbers work well for translation).

Still a very healthy number for a light car.

vixpy1

42,630 posts

266 months

Wednesday 4th April 2007
quotequote all
iaint said:
steve bowen said:
Just had a day of B & unclassified blatting in the Eunos that returned to me from tuning where it produced 186bhp@the wheels, so about 210bhp at the fly.


The fly estimate seems a little pessimistic to me. I'd expect there to be more like 40bhp+ lost in transmission and tyres. As a general rule of thumb the rx-7 loses about 18% or 55bhp (both numbers work well for translation).

Still a very healthy number for a light car.


Depends very much on the Dyno Iain

steve bowen

Original Poster:

1,268 posts

226 months

Wednesday 4th April 2007
quotequote all
It was a PowerDyne Mustang dyno. They didn't give flywheel power just wheel, I prefer be conservative with the flywheel guesses, wouldn't want a supposedly less powerful car keeping up

iaint

10,040 posts

240 months

Thursday 5th April 2007
quotequote all
vixpy1 said:
iaint said:
steve bowen said:
Just had a day of B & unclassified blatting in the Eunos that returned to me from tuning where it produced 186bhp@the wheels, so about 210bhp at the fly.


The fly estimate seems a little pessimistic to me. I'd expect there to be more like 40bhp+ lost in transmission and tyres. As a general rule of thumb the rx-7 loses about 18% or 55bhp (both numbers work well for translation).

Still a very healthy number for a light car.


Depends very much on the Dyno Iain


I know what you're getting at (I think) but, to be pedantic, the Dyno doesn't have any bearing on the amount of power 'lost' to the transmission and tyres (unless you're talking engine/hub vs rollers...)

How it calculated loss from run-down or whatever is another thing altogether!

From some fairly extensive dyno data over on MRC it's fairly clear that the estimated losses are pretty constant which indicates that mostly they're not to bad (or all equally crap).

Only thing we can say for sure is the wheels fighure is the only known and that it's all pub-talk anyway!

vixpy1

42,630 posts

266 months

Thursday 5th April 2007
quotequote all
iaint said:
vixpy1 said:
iaint said:
steve bowen said:
Just had a day of B & unclassified blatting in the Eunos that returned to me from tuning where it produced 186bhp@the wheels, so about 210bhp at the fly.


The fly estimate seems a little pessimistic to me. I'd expect there to be more like 40bhp+ lost in transmission and tyres. As a general rule of thumb the rx-7 loses about 18% or 55bhp (both numbers work well for translation).

Still a very healthy number for a light car.


Depends very much on the Dyno Iain


I know what you're getting at (I think) but, to be pedantic, the Dyno doesn't have any bearing on the amount of power 'lost' to the transmission and tyres (unless you're talking engine/hub vs rollers...)

How it calculated loss from run-down or whatever is another thing altogether!

From some fairly extensive dyno data over on MRC it's fairly clear that the estimated losses are pretty constant which indicates that mostly they're not to bad (or all equally crap).

Only thing we can say for sure is the wheels fighure is the only known and that it's all pub-talk anyway!


No, but different dynos read totally differently in the wheels, in particular the American made dynos (such as the Mustang), give much higher wheel figs, hence the smaller loss used here.


iaint

10,040 posts

240 months

Thursday 5th April 2007
quotequote all
vixpy1 said:
No, but different dynos read totally differently in the wheels, in particular the American made dynos (such as the Mustang), give much higher wheel figs, hence the smaller loss used here.


Really??? I guess they must use a different formula for the calculation of power Silly yanks!

steve bowen

Original Poster:

1,268 posts

226 months

Thursday 5th April 2007
quotequote all
something interesting regarding dynos, the guy that mapped my car on the road and the powerdyne rollers used to work at Thor and he said thor would have given me about 20bhp more at the wheels...

vixpy1

42,630 posts

266 months

Thursday 5th April 2007
quotequote all
steve bowen said:
something interesting regarding dynos, the guy that mapped my car on the road and the powerdyne rollers used to work at Thor and he said thor would have given me about 20bhp more at the wheels...


Not rollers, hubs.. and he's right, no losses through the tyres = higher number at the hubs.

Simple equation we work on which seems to work well:

Take the wheel power your achieve on a Dyno Dynamics

Take the loss given out by the dyno dynamics and split it exactly in half, add that half to the wheel figs and you have the figs that you would achieve on a Dynapack

for for the Mustang/Dynojet, add 10 to 15 % to the dynodynamics wheel fig and you will have an equivilent.