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LARKO 10 · 01-06-2003, 05:29

Are there any performance mods cheap or otherwise that can be done to these. They seem to have it allready sussed in the intake, head and exhaust area. Any ideas would be appreciated.

Martin · 01-06-2003, 08:15

Actually youll find the heads are the 'weakest' link in the whole package, theres probably upwards of 50kw waiting to be unleashed with a good set of alloy heads.

Top of the range Trickflow or Airflow Reseach would do the trick

WBT56 · 01-06-2003, 13:01

If it's a manual you can put a set of 0.74 ratio fifth gears into it instead of the ridiculous 0.61 ones in there now.

laminge · 01-06-2003, 13:06

Larko!

Just go to the extent I have.... or maybe not!

For a nice powerdyne at 6-10psi as a bolt on you really cannot go wrong and the 250 engine is hand built and fairly hearty!

anakha · 01-06-2003, 13:22

As Martin said, new heads are the go. Ditch the factory heads for a pair of AFR 185cc heads. Out of the box these babys make killer torque and hp. Depending on what Tickford did to the lower intake you may want to port that further as the Cobra/Explorer lower is a known restriction in hipo engines, expecially with the extra cubes you have. You may want to go an uprated set of springs in the heads to get some more rpm potential that your bottom end will allow. Naturally a custom cam to match the set would be an ideal finisher.

Aussie Pete · 01-06-2003, 22:12

For street car I vote for the Trickflow TrackHeat heads as they provide better mid range through more efficient combustion at high BMEPs. The AFRs flow better at the top end though - however, think of where you rev the engine the most........

Exhaust and UniChip are big movers on the 250 engine. Extractors are super important!

Petrol Hamster · 01-17-2003, 17:10

Have you got any gain figures for either exhaust or unichip for the 250 engine? I'd be interested to have a look...

(Frankly it seems quite arse kicking enough already...?)

Aussie Pete · 01-19-2003, 15:29

Quote:

Originally posted by Petrol Hamster
Have you got any gain figures for either exhaust or unichip for the 250 engine? I'd be interested to have a look...

(Frankly it seems quite arse kicking enough already...?)

I believe headers and exhaust will give approx 18-20kW. Add another 10 or so for unichip.

REDSTRIPE · 01-20-2003, 01:17

Mine is 199 rwkw with full Herrod exhaust & unichip tuned by Herrod. I believe ex factory it is about 176rwkw. This was done at about 2000 k's and now the ute has done approx. 13000 k's. It would probably be another 2 or 3 k'ws more now as the motor is run in and going beautifully - my wife says definately!

anakha · 01-20-2003, 02:11

Aussie Pete

I would dispute your claim that the Track Heats give better mid-range than the AFRs. The AFR 185 beats the the TFR heads from .300" intake lift up and all the way through on the exhaust side until .600". Now while the AFR sports a larger intake port volume of 185cc vs 170cc for the TFRs, the TFR intake port is shorter for that volume with a larger cross section. The AFR also wins the exhaust flow with a smaller port at 61 vs 66cc.

Sure flow numbers dont win races but consider the AFRs are fully CNC ported and are regarded to have excellent efficiency. In the only head to head dyno comparo using an identical engine combination where 11 different heads were tested on a 302ci the AFR 185s beat the Twisted Wedge (same as Track heat except with emissions compliance and not as good valvetrain gear) all the way through from 2500rpm on both torque and hp. Other main engine details were GT40 intake, B303 cam, 65mm TB and 70mm Cobra MAF and EEC. Article from Nov 2000 issue of 5.0 Mustang mag.

Now slap the same heads on a bigger ~340ci motor (ie Pursuit 250) and you reckon the TFR heads will beat AFR for midrange?