Modular Q

[billfisher]

speaking about physics...... let me throw this out.



as stoke length increases leverage on rotating assembly increases thereby improving power(torque).

as bore increases and pressure remains the same total thrust increases. (PSI)


if you keep the cylinder volume fixed and vary surface area and stroke the acceleration (rate of increase/decrease) of power = 0 (zero) at a square bore/stroke.





in other words... if you increase bore while decreasing stroke, thrust / torque decrease at exactly the same rate as bore/stroke leaves equal.


square bore /stroke = max hp/litre. for any displacement.

ford got away from 4" bore and 3" stroke for efficiency and total block length.

do the math. smaller bore = less thrust...
shorter stroke = less torque on mass.

i really don't care about all that crap. for tuning BIG hp try to beat 429. 3.59" stroke x 4.36" bore

 

[chini42]

^^^ exactly.

As for time slips, my best time was driving my 99 GT, which was a stock 5 speed coupe, with bald all-season radials, and ran [email protected], on a 2.2 60'. I haven't been since, and that was only my 3rd time ever running at a strip, so I'm sure the car had more in it with a better driver. But I got that slip shifting at 6000 rpms, anything less resulted in a slower time. Your Cougar has an auto, so you can't really experiement with this like I can. Trust me, shifting early costs you time.

I think that you guys are looking at the facts wrong. It's not that holding a gear longer is better because you make more power in that gear than you will in the next. Holding a gear a little longer SOMETIMES puts you in the powerband for the next gear. Hear is a table, using the above dyno for reference of what an 01GT shift's drop to when you shift at 6000RPM vs. 5500RPM. There is a only a 500 RPM difference in the shift points, but the change in the powerband is dramatic.

You need to go to a dyno, get your numbers and calculate what shift point's will put you in the powerband for each individual shift. Gear ratio's are not evenly spread out, so shift points change for each gear. I bracket race my Mach and shift at a different RPM for each gear change to keep me in the powerband.

01 GT @6000rpm
1-2 Shift
3543 RPMs
235Ft/lbs 158HP

2-3 Shift
4012 RPMs
236Ft/lbs 180HP

3-4 Shift
4511 RPMs
234Ft/lbs 200HP

01 GT @5500
1-2 Shift
3248 RPMs
229Ft/lbs 141HP

2-3 Shift
3676 RPMs
235Ft/lbs 164HP

3-4 Shift
4135 RPMs
236Ft/lbs 185HP

 

[Mike97gt]

TGJ + White96281gt

this is a good thread, lets not ruin it with personal insults.

 

[Mike97gt]

Stroker's are not the way to go, the only way to get more displacement with a Modular is Bore. Every car I have seen go with a stroker has not made the same power as a car with stock displacement and same mods. Stroker's are even more RPM limited than the stock displacement.

this is 1000 percent right.

big bore is the way to go with the modular motors PERIOD END OF STORY. we are already stroked out too much stock.

I have not seen posted to this thread yet of how the small bore of the 4.6 + 5.4 hurts performance by restricting valve size. the bigger bore 302 and 351 both can run bigger valves than a 2v mod motor with less shrouding (sp?) than the mod motor can.

I love fords but i hate to say it ford went in the wrong direction IMHO performance wise with the mod motor. the bore is to small.

 

[01Steeda]

I think that you guys are looking at the facts wrong. It's not that holding a gear longer is better because you make more power in that gear than you will in the next. Holding a gear a little longer SOMETIMES puts you in the powerband for the next gear. Hear is a table, using the above dyno for reference of what an 01GT shift's drop to when you shift at 6000RPM vs. 5500RPM. There is a only a 500 RPM difference in the shift points, but the change in the powerband is dramatic.

that is the primary point I was trying to make,.. but I just didnt bring it across that well. Good post.

 

[01Steeda]

this is 1000 percent right.

big bore is the way to go with the modular motors PERIOD END OF STORY. we are already stroked out too much stock.

I have not seen posted to this thread yet of how the small bore of the 4.6 + 5.4 hurts performance by restricting valve size. the bigger bore 302 and 351 both can run bigger valves than a 2v mod motor with less shrouding (sp?) than the mod motor can.

I love fords but i hate to say it ford went in the wrong direction IMHO performance wise with the mod motor. the bore is to small.

HAHA exactly, me and a friend who has a 347 pushrod motor were discussing this last weekend. he wanted to know why I didnt use bigger valves. I went with the biggest available and they are still muuuch smaller than what he can use.

 

[Mike97gt]

HAHA exactly, me and a friend who has a 347 pushrod motor were discussing this last weekend. he wanted to know why I didnt use bigger valves. I went with the biggest available and they are still muuuch smaller than what he can use.

I Know, I am now considering buying a 5.0 car ( I have never owned one before)

funny part is his 347 has a better bore to storke ratio than our stock 4.6

 

[01Steeda]

YEAH THEY MAKE GREAT POWER

 

[TGJ]

funny part is his 347 has a better bore to stroke ratio than our stock 4.6

It is still better than a Big-Bore modular setup too! Even the stock 5.0 has a better Bore to Stroke ratio than a Big-Bore.

Still, though, that( Big-Bore ) is what I have and intend to run with.

 

[Mike97gt]

It is still better than a Big-Bore modular setup too! Even the stock 5.0 has a better Bore to Stroke ratio than a Big-Bore.

Still, though, that( Big-Bore ) is what I have and intend to run with.

ohh yeah no doubt. I plan on getting a aluminum block out of a explorer and having it sleved for big bore when I build up the 01. I have been trying to tell people big bore is the way to go for a long time.

 

[White96281gt]

Anybody seen the June Mustangs & Fast Fords?

 

[billfisher]

big bore and 4v. are you going to push the valve and chamber size to go with the larger bore?