So what are you Guys reving your 2.5L's to?

[moparzrule]

Not sure what your saying Matt, the argument was all 2.5's, not 8 valve and Larry's engine makes more power 2.5 than 2.2.

Oh my bad, my memory is bad. Haven't been around for awhile...I guess I just thought this turned into a 2.2 VS 2.5 thread haha.

[turbovanman²]

Oh my bad, my memory is bad. Haven't been around for awhile...I guess I just thought this turned into a 2.2 VS 2.5 thread haha.

Well the dyno sheet was posted on his 2.2 vs 2.5 debate,

Yeah, the initial fire was 2.5's don't rev,

[tsiconquest88]

i didnt know the 2.5 could rev haha. not like the 2.2 that is. I still have BS though. I have gotten mine to around 5 or so. Sad thing is i burn 0 oil and engine runs strong with 2x's vac at idle and about 25+ off the pedal while driving in gear. BUT the engine is noisy as heck at startup till around 160 degrees the noise pretty much goes away. I posted about this a while ago though. Think its just wristpin slap though. Oil pressure is perfect, in fact little higher than i see people post theirs is. In fact my van starts pulling even harder at its higher rpm. A few instances i was at the 4-5 mark and it pulled harder out of no where, i was boosting and suddenly wham i had gotten even more power. This typical? Cus it dont act liek that all the time which is weird, i had it happen a couple times and most of the time i dont get the same kick in the --- at that rpm. always powerful below 4k though.

[turbokid]

Very interesting reading this thread.
Sort of on topic but Larry Bufford blew up the 2.5 in his hybrid RWD Sundance.
So he decided to put a 2.2 on the car.
With the EXACT same SET up (minus ofcourse the alterations he made to his cal concerning the 2.2) he made the same amount of HP and slightly less torque then the 2.5 motor but lost .3 of a second on the quarter mile from the 2.2's lack of ability to spool his big --- holset off the line to get the 60 foot he was getting with the 2.5.
Just some food for thought.

[tsiconquest88]

yea im sure, the 2.5 def kicks in low range power faster than the 2.2

[turbokid]

He says he noticed no real difference in the top end between the two motors.
Again food for thought.
I like the 2.5 for street to street play because of the torque. I mean my 2.5 lebaron stock would smoke the pants off of the t2 maserati anyday of the week.
But I love my 2.2 t2 5 speed Tona. It definitely PULLS a lot harder in the upper rpm's

[turbovanman²]

With the EXACT same SET up (minus ofcourse the alterations he made to his cal concerning the 2.2) he made the same amount of HP and slightly less torque then the 2.5 motor but lost .3 of a second on the quarter mile from the 2.2's lack of ability to spool his big --- holset off the line to get the 60 foot he was getting with the 2.5.
Just some food for thought.

Wow, lost .3, that's amazing,

[bris09]

Has anyone designed a cam for the 2.5. To my knowledge all the cams are based on the 2.2. My thinking is with the longer stroke you need the valves to stay open longer to take advantage of the stroke. A cam based on a 2.2 would close the valve earlier causing the piston to build cylinder pressure at the end of the exhaust stroke and create a really high vacuum at the end of the intake stroke. Both of these will put pressure on the piston causing it to slow down.

I always hear that a 2.2 with the exact same setup will out perform a 2.5. To me that's not a fair comparision. What happens when you give the 2.5 a cam with a duration better suited for it's stroke? Providing you did the work to move the air wouldn't the power band move into a higher rpm range and become compariable to the 2.2 while producing more power?

[glhs875]

Has anyone designed a cam for the 2.5. To my knowledge all the cams are based on the 2.2. My thinking is with the longer stroke you need the valves to stay open longer to take advantage of the stroke. A cam based on a 2.2 would close the valve earlier causing the piston to build cylinder pressure at the end of the exhaust stroke and create a really high vacuum at the end of the intake stroke. Both of these will put pressure on the piston causing it to slow down.

I always hear that a 2.2 with the exact same setup will out perform a 2.5. To me that's not a fair comparision. What happens when you give the 2.5 a cam with a duration better suited for it's stroke? Providing you did the work to move the air wouldn't the power band move into a higher rpm range and become compariable to the 2.2 while producing more power?

I think so!

[Ondonti]

Not too much on topic there, since he specificially states that both engines were 16 valves. I knew something was wrong when I looked at the dyno chart. With the exact same top end on a 2.5 (on an 8 valve) it will not make as much HP as a 2.2 and certainly won't rev as high.
This only further proves my point. The 8 valve heads are restrictive enough as it is...pumping more intake and exhaust through because of larger displacement only hurts more. For an 8 valve, 2.2 FTW. For a 16 valve hybrid, 2.5 is fine but personally I'd still rather have a 2.2 anyway. The results speak for themselves-

http://www.turbo-mopartimes.com/

Look at the majority of the peope in the 10 second bracket, not counting the 2.4's it's mostly 2.2's. And the only one in the 9's? 2.2. How can you honestly argue with that? 7 out of 10 people in the 10's are running 2.2, and 7/10 in the 11's are running 2.2's.

This is simply an observation, not evidence of anything. The 2.2 existed first so thats what the crowd has been stuck on before the 2.5 ever existed.
Now the dyno and track evidence from 2 cars that use back to back fair comparisons, that provides a heap of evidence that the 2.2 camp lacks. Lack of evidence does not make something true.

BTW, 7/10 is not even statistically significant with a 10 car field. It still has nothing to do with what you are trying to prove even if it was statistically significant.

Regarding Simon's powerband, I see no evidence of power falling off. If you have seen enough dyno sheets like his, you will know that a slowly falling torque curve is likely to keep slowing falling unless the valves float or something else fails. This means HP will keep flatlinelining for quite a few RPM's until backpressure gets too high, or something else becomes a limination.

He already stated that his cat was completely clogged so that further ruins anyones attemps to say his powerband is anywhere near dropping off. The clogged cat is probably the reason the torque curve started dropping. There was only so much exhaust flow that could pass through the cat so there is no way HP could have increased once that limit was reached. Higher rpms just mean more exhaust gas flow and even more HP loss from reversion caused by high exhaust backpressure.

Put a darn cutout on there with a small bullet muffler to appease the crybabies at the track and I bet the dyno will read some crazy numbers if he can finally get his fueling tuned reliably. Should also mean he won't have to run tons of timing to make power.

[Ondonti]

Has anyone designed a cam for the 2.5. To my knowledge all the cams are based on the 2.2. My thinking is with the longer stroke you need the valves to stay open longer to take advantage of the stroke. A cam based on a 2.2 would close the valve earlier causing the piston to build cylinder pressure at the end of the exhaust stroke and create a really high vacuum at the end of the intake stroke. Both of these will put pressure on the piston causing it to slow down.

I always hear that a 2.2 with the exact same setup will out perform a 2.5. To me that's not a fair comparision. What happens when you give the 2.5 a cam with a duration better suited for it's stroke? Providing you did the work to move the air wouldn't the power band move into a higher rpm range and become compariable to the 2.2 while producing more power?

Even intake runner and exhaust runner length/diameter all might need to change to compliment the 2.5.

all these factors that are biased to the 2.2 along with priceless evidence showing 2.2 superiority to simple be a "belief" show how silly it is to mock a 2.5L when the person who "showed you how much worse it was" really had no idea what they were doing. Jokes on you

Of course the destroked 2.2 (to 2.0) still gets people excited. They just need to realize that the destroking was for displacement purposes in motorsport, not for a power advantage. They probably prefered the lower piston speeds of the short stroke motor for potential endurance use.

[turbovanman²]

Put a darn cutout on there with a small bullet muffler to appease the crybabies at the track and I bet the dyno will read some crazy numbers if he can finally get his fueling tuned reliably. Should also mean he won't have to run tons of timing to make power.

I am going to, but still want to do my goal on full exhaust, to satisfy my goals as a true daily driver,

[mopar-tech]

Popcorn

[Juggy]

Very interesting reading this thread.
Sort of on topic but Larry Bufford blew up the 2.5 in his hybrid RWD Sundance.
So he decided to put a 2.2 on the car.
With the EXACT same SET up (minus ofcourse the alterations he made to his cal concerning the 2.2) he made the same amount of HP and slightly less torque then the 2.5 motor but lost .3 of a second on the quarter mile from the 2.2's lack of ability to spool his big --- holset off the line to get the 60 foot he was getting with the 2.5.
Just some food for thought.

he prolly wasnt leaving the line hard enuff. ive seen larry drive and have met him in person. he even admits that he should try to give it a little harder out of the hole. hope he switches to auto tho!!! that car would launch hard and be consistent. less problems spooling at the line too.

[turbovanman²]

Popcorn

Oh come on, this is a good thread,

Everybody has their favourite, some 2.2's, some 2.5's, 3.0L's etc, and that will never change.

[turbokid]

he prolly wasnt leaving the line hard enuff. ive seen larry drive and have met him in person. he even admits that he should try to give it a little harder out of the hole. hope he switches to auto tho!!! that car would launch hard and be consistent. less problems spooling at the line too.

He said it wouldn't spool off the line half as hard as the 2.5 does. It's obviously something with the 2.2 because alas he is switching back to the 2.5! He is taking the good running 2.2 back out.
I know Larry pretty well and if it was workable, he would do it.
Q

[Vigo]

I am switching to 2.2 in my Spirit for MPG! And variety!

[mopar-tech]

Everybody has their favourite, some 2.2's, some 2.5's, 3.0L's etc, and that will never change.

What kills me is folks with the "be all to end all" attitude.

Find the package that suits *your* needs and go for it I always say.

[mopar-tech]

I am switching to 2.2 in my Spirit for MPG! And variety!

The only thing I would have done different on mine was a slightly heavier flywheel or a 3.85 gearset.

It was a fun car to be sure but the 2.2 + S-60 Turbo + light flywheel + 3.50 gearset in a Spirit makes it more a highway machine than a in town bomber.

[Vigo]

My setup will be almost straight stock t2:

85 2.2 motor with 782 head.
Tbi cam w/ 690 gear
stock t2-style garrett w/ 2.25" sv, 2.5" full exhaust
t2 rad/ic
Unmodified 2-pc intake, +20s
Stock exhaust manifold.
3.50FD 520


Just all stock stuff bolted together. I want to start at about 30hwy mpg and tune my way up past 35, hopefully higher.