My Take on CMDPs
 

I read a lot about CMDPs before my install and there is a lot of conflicting information out there. So after installing them, I wanted to give you guys my take. I do not have any hard dyno numbers or even track times, so this is all theoretical butt dyno impressions. Keep in mind I already have C&L Intake and Kooks LT headers. Also with CMDPs a new tune must be loaded, so some of the effects I am feeling MIGHT be related to the tune and not directly to the plates.

I’ll talk about the most important part first. The gains.......
My cars without a doubt pulls harder at WOT. It is not borderline. It accelerates significantly faster according to my official calibrated butt dyno.

I have a stretch of roadwhere Itake my car to have fun and test things. It is a VERY unscientific 1/4 mile, (Between 2 mailboxes[8D]) I gained ~4MPH. (I am up to~109)Let me reiterate this is not exactly a 1/4mile and it is just a public road and I have nothing but the speedometer to go by, I just use it to helpjudge gains and have a little fun it is however fairly consistent. The gains are somewhat close to the gains I felt with LT headers. I realize that most graphs show LTs at 20ish and CMDPs at 10ish but it seems closer than that to me on the butt dyno. (I don’t know if that means my LTs gave me less or the CMDPs gave me more, or I am crazy. It’s just an observation about the difference in pull.) They defiantly gave more than UDPs. However, I think the gains of the CMDPs would be less without the LTs.

I also read a lot about a possible loss in power in the lower RPMs. Brenspeed cautioned me against installing the CMDPs without gears for this very reason. I did have a loss down in the RPMs. BUT it only occurs at partial throttle ¼ pedal and above or so. For me it was very apparent the first time I drove it after I installed the plates. The partial throttle pull in 5th gear at 45ish was always sluggish but it is Geo Metro slow now. And slight blips of the throttle (I do not mean stomping the pedal just small gooses) in lower gears does not give the aggressive jump it did before the plates. What does this mean? Well to me nothing. I never drive in 5th gear at 45 and if I want to accelerate I will just push the pedal down more or shift slightly later. I don’t want to scare anyone off with these statements it is NOT a large change. It is very minute under normal driving conditions, but if you are bogging it down and driving it like a grandma all the time you will notice a loss in low end power. Also IMO the tune I had before the plates made the throttle too sensitive in 1st gear. So to me the drivability is better. It made the car mild mannerly when parking lot cruising yet meaner when you want it to be.

I was also asked about added valve train noise after the installation. I do not hear anything new. That said I am not sure I would. I was asked to stick my head in and listen. I can hear some valve train noise now but I could before also. I really can’t say if I hear more or not. I am kinda hard of hearing.

Let me reiterate that since I had to install a new tune, some of the improvements and losses could be due to the new tune. It was tuned by the same person though so I would expect the tunes to be similar.

RE: My Take on CMDPs
 

I wouldn't be supprised if you picked up 15 RWHP with the CMDPs. Not bad for a $97 mod [8D]

RE: My Take on CMDPs
 

No doubt it is worth the money. This is a must have mod. Atleast with LTs and intake.

RE: My Take on CMDPs
 

Good point, I did my delete plates before I put in my Kooks....I bet they work a little better now. I also agree with your overall analysis of the plates.

On a side note when I am standing outside my carwhile my engine is idling, I can hear increased valve train noise. It isn't anything distracting though.

RE: My Take on CMDPs
 

Great info! Thanks for the post!

RE: My Take on CMDPs
 

Where do you guys get your delete plates?

RE: My Take on CMDPs
 

Let me state this, I had an Evo tune and switched to Brenspeed when I did my cams and I lost my awesome throttle response.

With the Brenspeed tune I have a delay once again... I have the CMCV's ready to go on after all my body repairs(crashed @ track) and when I can afford the dyno tune I had scheduled before my accident.

I said that because if you had a different tune before Brenspeed that may have been why your throttle response isn't that great now. I also realize my cams are for top end, but this is from all points where I notice the throttle delay.

-Jeff

RE: My Take on CMDPs
 

I got mine at D'Agusto. That might not be spelled right maybe someone can correct me. I got them for Christmas and they were very hard to find then, but I think alot of places have them now. PMP would be a good place to look.

RE: My Take on CMDPs
 

You could be right about some of it being in the tune. However, Benspeed made my previous tune aswell, and it isnt really the initial response. It is the pull it has once it does respond that seems to have been decreased at low throttle. It could very well be in the tune though. There are settings that effect what the throttle position is in relation to the pedal. (Just because the pedal is 1/2 down doesnt mean the throttle is half way open.) It is possible this has been changed and I am simply giving the car less gas than I was before. I dont think so though since I am still using the same tuner. It seems like he would keep it consistant. I havnt called and ask, because it is a very small loss and it doesnt bother me at all. The extra WOT HP WAY more than makes up for it.

RE: My Take on CMDPs
 

haha CMDP's are coming out now as a fantastic mod. interesting. seems like they kind of really came into their own and suddenly there were a flood of threads about it. reading this, i think i might get some after i do 4.30 gears. i hadn't even really considered it before. thanks so much for the write up.