Evaluation of my Timing Slips?
Turbo Mini Forums

I'm trying to evaluate my figures from last weekend, but I don't really know what I'm looking for etc. So I'm asking you guys for help?

What I would like to know is if its me driving crap or the car that's needs work to go faster, so I can concentrate on improvements in the right place.

Spec: N/A 1380cc 11.5:1 compression, AGSP 300 deg Scatter Cam, Morspeed full race head, MJolt, 45DCOE, s/c drops, 3.44 FD, 13" wheels with A539's... Pulled a 103bhp and 104lb/ft last year before a 1.5:1 rockers and a lightened pre-verto.

Comments suggestions most welcome, good or bad?

Times are here:

Do you happen to know what your revs were as you crossed the line?
Where do you make peak power?

Im thinking that a 3.6 or higher FD may be beneficial

Edited by Nic on 15th Jul, 2009.

Looking at that your 60ft really improved throughout the day, and after the launch I don't see how anyone who is trying to go fast could go far wrong. Especially (and I'm not being funny) in a car running 16s.

My 998 turbo runs simialr times, and I estimate it has 20bhp less than you. Not sure how light your estate is, my mini is probably slightly heavier than when it left Longbridge.

What RR did you use? have you had it RRd since fitting the 1.5s?

With the spec as it is I'd expet it to be faster than it is.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

2.5 seconds on road tyres is a good 60ft in my book.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

I'd imagine that spec with an AGSP and a 45dcoe should be well over 103bhp. Mine's a similar spec with an MED full race 37x30 head and a moronspeed trackday cam and it made 100 at the wheels!

Never had it down the strip though.

Also, shouldnt peak power be higher than 6800 with the AGSP?

Mr. Prawn, the friendly Crustacean- slowly making steps towards forced induction.

Your 60ft could improve.
Before I fitted my Salisbury I pulled 2.4 60s on 10s with a 4.1 diff.
Your 3.4 diff should be less prone to wheelspin and you should have more grip from the 13s.
If your peak power is 6,800 change gear at around 7,400

Paul.

I seriously doubt it!

So would you agree im getting there in terms of my launch, with a small room for improvement.

But I really need to look at the engine etc to get faster 1/4 mile times?

Where is that credit card? :)

Anton - gearing is a big factor on an engine making power in the mid range/top end - its always a compromise, I'd run that spec on a 3.9 for max accel - pain in the arse on the road! - I'll dig out my "thrust" curves for similar spec engine that was in my gold car, what this shows you is the actual accelerative force available at the wheels in each gear - v road speed as you go through the rev range. If you had a torque curve for yours I could pop it on the same graph?

JK

If Carling made Mini engines
it would probably be like this one!

Hmmm.. Interesting.. Thanks John... I will have a dig through my files at home and try and dig out the last RR graph.

Hmm... i remembered my peak rpm wrong... here is the graph...
http://www.facebook.com/photo.php?pid=5736...04&id=513372695

ok Anton - I'll do a graph with that info as the "worst case"

1.5 ratio rackers will wake the motor up a lot as well - essential on these duration cams to get valve lift up. Are you running 38mm chokes in the 45 and is it a "good" manifold - may be time for another RR session

i'll post a graph later

JK

If Carling made Mini engines
it would probably be like this one!

my spec is similar just a difference in cam and last year i was doing low 14's

Ok - a quickie graph to compare. Antons line is built using the torque curve from his post above, std helical box ratios, 3.44 FD and 10 inch tyres. The "other" curves are from a similar spec 1380 to Antons running through a 3.9 fd and MS clubman s/cut gearset. Each curve shows the force available at the wheels to move the car, it doesn't account for car weight or inertia effects - its just what the car sees at the road through the gears. In short after 20mph in first gear Antons car wouldn't see which way the "other" car went! You can see how the wide ratios hold the car back - typical for an n/a car, if it were a turbo the extra torque would mask the ratio effect to some extent. These sort of graphs are handy to work out gearchange points - as is the case with Antons theoretical spec wringing the car out to 7500rpm won't make it accelerate any faster than changing 500/750rpm earlier - whereas with the clubman gearset wringing it to 7500 is the fastest way to accelerate as the thrust lines don't cross. The "other" spec 1380 would run low 14's all day long.

JK

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If Carling made Mini engines
it would probably be like this one!

Far too technical shit for me. Means fuck all

Paul

I seriously doubt it!

hehe - ll you have to do is look at 4 lines!

If Carling made Mini engines
it would probably be like this one!

So its engine torque, calculated back through the multiplication of the gear train, then converted to a force by using the torque as the turning moment multiplied by the radius of the wheel/type, plotted against road speed which is a function of gear ratio, RPM and tyre size.

excel and F11 is your freind here...

lol

Tom - it would take me much longer to explain than you have made it sound -yes

JK

If Carling made Mini engines
it would probably be like this one!

I seriously doubt it!

paul,

If i have my head round this right....

the 4th gear curve is your tourque curve from the rollers (or the top of it anyway...)

the 3rd gear curve is created by multiplying the 4th gear torque by the gear ratio to give the higher torge effort in third and dividing the speed by the gear ratio to give the lower speed of third.

repeat for 2nd and 1st...

mucho thanks for that John, Makes interesting reading... and surprisingly I think I get it..

In short, I need to look at the following:

- Investigate the reasons for low power output/peak power?
- Obtain a clubman gear set
- Fit a 3.6 or 3.9 FD

then possibly run a 14? or am I missing something?

just sell the head/cam and turbo it instead

Sounds like a great plan Nick! I've spent years trying to get more out of 1380, and I've reached about 120bhp, but it's still not fast enough! I eventually came to the conclusion that forced induction is the way forward, so I ended up here :)

Mr. Prawn, the friendly Crustacean- slowly making steps towards forced induction.