After doing quite a bit of math...
Thread Starter
Senior Member
Joined: 04-01-09
Posts: 971
Likes: 0
From: Melbourne, FL
After doing quite a bit of math...
Anyways, i always wanted to buy the 2.4 mani for my L61 because they sell it on crate engine depot and they say you gain like 13 horsepower for an inexpensive mod. After looking at the dyno graph, i noticed that although you get the horsepower its only way up the rpm range and you lose quite a bit of torque around 3000-4000 rpm. So... i decided to crunch all the numbers comparing the stock dyno to the 2.4 mani dyno and learned that the intake will only make you faster to certain speeds and even sometimes slow you down. Results:
0-End of 1st gear: .12 seconds faster with the 2.4 mani
0-60: Dead even... no change
0-End of 2nd gear: .26 seconds faster with the 2.4 mani
1/4 Mile: .06 seconds faster with the 2.4 mani
0-25 and below: slower
0-50 on to 60: slower
now before buying the 2.4 mani, you might need to rethink it being so much bang for the buck. 13 horsepower sounds like a lot and it is but you only get that kind of power 5500 rpm and above. people may say wow my car feels so much faster but its just a butt dyno and since they payed 300 for something it messes with the mind.
Discuss...
0-End of 1st gear: .12 seconds faster with the 2.4 mani
0-60: Dead even... no change
0-End of 2nd gear: .26 seconds faster with the 2.4 mani
1/4 Mile: .06 seconds faster with the 2.4 mani
0-25 and below: slower
0-50 on to 60: slower
now before buying the 2.4 mani, you might need to rethink it being so much bang for the buck. 13 horsepower sounds like a lot and it is but you only get that kind of power 5500 rpm and above. people may say wow my car feels so much faster but its just a butt dyno and since they payed 300 for something it messes with the mind.
Discuss...
Thread Starter
Senior Member
Joined: 04-01-09
Posts: 971
Likes: 0
From: Melbourne, FL
this is untuned and the mods were gmpp intake, gmpp catback exhaust and of course the intake mani.
and i found these numbers through a lot of engineering study and fairly simple physics involving averaging force and applying that to calculate acceleration.
and i found these numbers through a lot of engineering study and fairly simple physics involving averaging force and applying that to calculate acceleration.
doesnt work that way, you need real numbers on the car..like, watching it on the road measuring things...
secondly, tuning will change this 100%
third, if you open the exhaust (mani and dp) you will see a better gain from this mod as it will beable to flow more eai then the 2.2 mani would have beenwitht the same other mods
secondly, tuning will change this 100%
third, if you open the exhaust (mani and dp) you will see a better gain from this mod as it will beable to flow more eai then the 2.2 mani would have beenwitht the same other mods
Thread Starter
Senior Member
Joined: 04-01-09
Posts: 971
Likes: 0
From: Melbourne, FL
but reallly... it does work like that. you cant disprove physics man and i made sure all the calculations were accurate.
for your other point... a tune should open up the lower torque quite a bit. looking at the dyno, i noticed that the a/f ratio crapped until 3700 rpm which is right where the torque began to climb so that can be fixed but again thats another few hundred bucks spent. im not really sure about the other exhaust parts helping out.
for your other point... a tune should open up the lower torque quite a bit. looking at the dyno, i noticed that the a/f ratio crapped until 3700 rpm which is right where the torque began to climb so that can be fixed but again thats another few hundred bucks spent. im not really sure about the other exhaust parts helping out.
Senior Member
Joined: 09-25-06
Posts: 1,860
Likes: 0
From: USAG Stuttgart, GER
Well he has done all that to his car and I believe he has stage 1 cams. Hes putting down over 180whp now right? I believe vince did a tune on his car before the cams and he had the 2.4 intake, and full exhaust and made a significant gain over stock.
The 2.4 manifold does shift the powerband, but if you can take advantage of that(spin higher, with better cams) you would see the biggest gains.
The problem in your calculations is that your looking at someone elses dyno graph with the manifold. Your car will produce a different graph. That and the location and time of year will cause those numbers to change. Its almost like comparing dyno numbers to a different dyno. It shouldn't be done.
The 2.4 manifold does shift the powerband, but if you can take advantage of that(spin higher, with better cams) you would see the biggest gains.
The problem in your calculations is that your looking at someone elses dyno graph with the manifold. Your car will produce a different graph. That and the location and time of year will cause those numbers to change. Its almost like comparing dyno numbers to a different dyno. It shouldn't be done.
Thread Starter
Senior Member
Joined: 04-01-09
Posts: 971
Likes: 0
From: Melbourne, FL
Well he has done all that to his car and I believe he has stage 1 cams. Hes putting down over 180whp now right? I believe vince did a tune on his car before the cams and he had the 2.4 intake, and full exhaust and made a significant gain over stock.
The 2.4 manifold does shift the powerband, but if you can take advantage of that(spin higher, with better cams) you would see the biggest gains.
The problem in your calculations is that your looking at someone elses dyno graph with the manifold. Your car will produce a different graph. That and the location and time of year will cause those numbers to change. Its almost like comparing dyno numbers to a different dyno. It shouldn't be done.
The 2.4 manifold does shift the powerband, but if you can take advantage of that(spin higher, with better cams) you would see the biggest gains.
The problem in your calculations is that your looking at someone elses dyno graph with the manifold. Your car will produce a different graph. That and the location and time of year will cause those numbers to change. Its almost like comparing dyno numbers to a different dyno. It shouldn't be done.
i must be more hungover then i thought cause i thought it said meth not math. 
Senior Member
Joined: 03-19-09
Posts: 848
Likes: 0
From: Austin, TX
http://www.crateenginedepot.com/stor...t-W67C144.aspx
Plus here's some graphs I made a little easier to see from their website.
Blue=stock manifold
Red=2.4 manifold
Plus here's some graphs I made a little easier to see from their website.
Blue=stock manifold
Red=2.4 manifold
Last edited by weiss27md; Jun 24, 2009 at 08:08 AM. Reason: Automerged Doublepost
thanks for the compliments 
and im running stg 2 cams
but what i was saying is that in no way is the power on these cars linear...at all lol, it would take some VERY complex equations to figure the specific gain/loss throughout the hp/tq curves
also, i will admit, if you lookat my dyno graph...its almost like i have vtec hahaha, or turbo lag, cause it REALLY kicks in at 3500-4000rpm..but thats because of the intake mani and cams both shift the power band higher
and im running stg 2 cams
but what i was saying is that in no way is the power on these cars linear...at all lol, it would take some VERY complex equations to figure the specific gain/loss throughout the hp/tq curves
also, i will admit, if you lookat my dyno graph...its almost like i have vtec hahaha, or turbo lag, cause it REALLY kicks in at 3500-4000rpm..but thats because of the intake mani and cams both shift the power band higher
Junior Member
Joined: 09-16-07
Posts: 448
Likes: 0
From: Las Vegas
My question is where does that PowerEnrichment come into play, isn't it a 5 or 10 seconds of full throttle and then it starts dumping more fuel in? Won't that have something to do with the drop in AFR?
Senior Member
Joined: 09-09-07
Posts: 1,377
Likes: 0
From: Vancouver, WA
Power Enrichment.....the most noticeable change once you get tuned.
Essentially, as seen in the graph, the 2.2 on stock tune runs VERY lean for the first few seconds of acceleration. GM implemented this as a way to conserve gas a little bit, and most daily drivers don't notice it or know how to notice it till after tune.
A major part of the tune basically kicks your engine into "give em all you got, right when they want it" mode.
The AFR on that dyno always seems a lil odd to me. My stock dyno didn't lean out near as heavy on the top end as their baseline dyno.
can't wait to get this mani on.
Essentially, as seen in the graph, the 2.2 on stock tune runs VERY lean for the first few seconds of acceleration. GM implemented this as a way to conserve gas a little bit, and most daily drivers don't notice it or know how to notice it till after tune.
A major part of the tune basically kicks your engine into "give em all you got, right when they want it" mode.
The AFR on that dyno always seems a lil odd to me. My stock dyno didn't lean out near as heavy on the top end as their baseline dyno.
can't wait to get this mani on.
Power Enrichment.....the most noticeable change once you get tuned.
Essentially, as seen in the graph, the 2.2 on stock tune runs VERY lean for the first few seconds of acceleration. GM implemented this as a way to conserve gas a little bit, and most daily drivers don't notice it or know how to notice it till after tune.
A major part of the tune basically kicks your engine into "give em all you got, right when they want it" mode.
The AFR on that dyno always seems a lil odd to me. My stock dyno didn't lean out near as heavy on the top end as their baseline dyno.
can't wait to get this mani on.
Essentially, as seen in the graph, the 2.2 on stock tune runs VERY lean for the first few seconds of acceleration. GM implemented this as a way to conserve gas a little bit, and most daily drivers don't notice it or know how to notice it till after tune.
A major part of the tune basically kicks your engine into "give em all you got, right when they want it" mode.
The AFR on that dyno always seems a lil odd to me. My stock dyno didn't lean out near as heavy on the top end as their baseline dyno.
can't wait to get this mani on.
we are also lowering a locals car sat night :P
Thread Starter
Senior Member
Joined: 04-01-09
Posts: 971
Likes: 0
From: Melbourne, FL
wow i just noticed that some of you are from washington on this post. i live in florida but im visiting my brother in vancouver, wa until the 9th. i wish i could go to portland raceway on the 4th but im going over to rockaway beach in oregon.
Who knows...maybe it was the manifold....maybe the better flowing catback....maybe even the tune. But for sure my car feels improved after...lol
NWAE Quit stealin my vtak quote! lol Although I've begun to notice that my car seems to act as if it has that lag as well lol its funny with the hondas
NWAE Quit stealin my vtak quote! lol Although I've begun to notice that my car seems to act as if it has that lag as well lol its funny with the hondas
Who knows...maybe it was the manifold....maybe the better flowing catback....maybe even the tune. But for sure my car feels improved after...lol
NWAE Quit stealin my vtak quote! lol Although I've begun to notice that my car seems to act as if it has that lag as well lol its funny with the hondas
NWAE Quit stealin my vtak quote! lol Although I've begun to notice that my car seems to act as if it has that lag as well lol its funny with the hondas
it was funny with that modded rx7 just a lil bit ago...and he stood NOOOOO chance