Would you swap in a Cobra motor?

[01SN8K]

why should he care about a little weight gain? it is offset by the power gains. it wouldnt be much if any weight gain. an all aluminum motor versus one that is iron. the cobra motor would be best. it can breathe better and has a broader rpm and power band than a SOHC.

 

[300bhp/ton]

why should he care about a little weight gain? it is offset by the power gains. it wouldnt be much if any weight gain. an all aluminum motor versus one that is iron. the cobra motor would be best. it can breathe better and has a broader rpm and power band than a SOHC.

There are 2 reasons really (although not specific to Mustangs as this engine combo evidently works in Cobra's, but the physics behind the theory still apply).

1. handling, if there is more weight over the front wheels then the front/rear power distribution is far from ideal. Also if it increases the wieght of the engine higher up it will raise the cars centre of gravity increasing its roll angle.

2. power to weight. How much more power will the DOHC produce over the SOHC, will it outweight the extra weight of the DOHC.

When Jaguar where developing the V12 they tested DOHC setups, they did produce more power than the SOHC designs but not by enough to offset the extra weight. Essentially the NET ('net being the VERY IMPORTANT word here) was not sufficent as there would still be the detrement to handling. Hence the Jaguar V12 is only SOHC design. Although it has proven good enough to produce 629bhp n/a from the stock 5.3 litres capacity in full out race tune.

 

[Gearbanger 101]

2. How much more power will the DOHC produce over the SOHC?

Answer: With a blower......much, much more! Besides...the weight gain you'd get by swapping out a DOHC into the place of the SOHC would about equal the weight of a SOHC and a blower anyway. You don't see anyone complaining about handling after adding a blower to their 2V, do you? I don't think the additional weight gain he's going to see with the DOHC swap is going to affect the handling as significantly as you think it will.

 

[01SN8K]

if there was an affect to handling then ford would not put a DOHC in a mustang. a cobra like mine as tested by SVT pulls .9 g's on a skid pad.if there are issues it is slight and can be fixed with a set of lowering springs. and last time i looked at a stock mustang they were kinda high up stock so regardless of the motor there is already a handling problem. they are not the best for cornering or slalom.

 

[300bhp/ton]

Answer: With a blower......much, much more! Besides...the weight gain you'd get by swapping out a DOHC into the place of the SOHC would about equal the weight of a SOHC and a blower anyway. You don't see anyone complaining about handling after adding a blower to their 2V, do you? I don't think the additional weight gain he's going to see with the DOHC swap is going to affect the handling as significantly as you think it will.

As I said it was purly theoretical, but it all depends how much power you want, a SOHC 2v will put out 500rwhp, if thats all your after then the extra potential of the DOHC is almost wasted, if your going 700+rwhp then its a different story. Also the charcteristics of the engines will be different, the SOHC should feel more grunty down low but a little breathless up top COMPARED to the DOHC which will be a more revvy motor.

This is the classic case of which tuning approach to go for, in the UK hot hatches are the main stay (had several over the years), in a straight line the 16v revy engines are the quickest, but in the real world out there on the public roads the grunty 8v engines are nearly always the faster cars point to point even though they have less BHP.

Assuming the new 3v engine will handle FI ok it probably will be the best compromise all round, smaller overall dimensions and less weight than the DOHC but able to produce more BHP than the SOHC 2v unit.

if there was an affect to handling then ford would not put a DOHC in a mustang. a cobra like mine as tested by SVT pulls .9 g's on a skid pad.if there are issues it is slight and can be fixed with a set of lowering springs. and last time i looked at a stock mustang they were kinda high up stock so regardless of the motor there is already a handling problem. they are not the best for cornering or slalom.

Skid pad means nothing in real terms as it is about mechanical grip, tyres play the largest part there. Handling is about feel and control as when cornering there is a weight transfer across the vehicle.

When the 03 Cobra was 1st tested it was noted how well it handled, but also that it felt nosie heavy compared to the previous Cobra's, which the SVT engineer explaned was because of the extra weight from the cast iron block.

 

[def1eppard]

Its simple.

Cobra > GT