The graph was very solid. I didn't care to print it out really bc I was thinking of going back for speed density. But the curve on it was good and the car runs solid.

Im running a ford 8.8 rear with 4.10 gears

 

Short answer, yes, ditch the maf, go straigh 4" intake from filter to throttle. Several of us actually predicted it would underperform with that 85mm maf in place. So here's the mathematics:

* 85mm maf area is 5765 sq-mm
* 102mm throttle area is 8167 sq-mm

So, if you have a 4" CAI intake tract AND a 102mm throttle, necked down to a 85mm maf, you would not think it would be that restrictive, but as was said earlier in the thread... The heads and cam you have chosen can move a ton of air, and necking it down is like forcing it to breathe through a straw. It's 30% reduction in cross section area at the maf. In my builds, I try to always have the throttle be the limiting factor, since that's it's job - to control engine speed and power by restricting airflow ingress.

Now, here's the next problem. the 102mm card style maf blocks a huge portion of the flow area. So when you swap to a 102mm maf, you gain NOTHING vs a 85mm maf. This then causes the perception that the maf is not the restriction.

For a simple data check, ask the tuner what the map reading was at WOT at max power. If it was lower than ambient, you have an intake restriction - which again points to the maf and possibly the air filter/CAI being too small in addition to the maf. If the map was not lower than ambient, then i'm wrong. Simple enough. If that data is not available, another quick and dirty test is to pull the CAI, run on the dyno open throttle, and see the difference it makes. I figure with your exhaust being wide open like it is you might be surprised. I do find a X pipe does better than open duals, but only by a little bit. For the standpoint of why 440 and not 470 hp, the exhaust is not the issue.

 

Thank you man for the clear cut answer. That was very helpful.

Okay so I'll leave the turn downs alone. Now will I benefit from a dual true 4" intake? Or a single 4" intake will do?

I currently have a 3.5" single but it's more of a short ram intake I guess you can say. I was trying to post a picture of it on here but the app keeps crashing when I do so.

So I made the intake myself from aluminum piping from Spectre. I saw they have a 4" dual aluminum piping. I was thinking of going with that set up. What do you think? Duals or single? Since my car is an rx7 there is no direct fit one for it.

I found Spectre had the best options. What do you think?

Regarding data logging. I can take the car and do a 4th gear pull and log on dash command and see what my intake and map is reading out at WOT. I'll try and do that today and post the results.

Thank you guys for all the help!

 

The math won't be perfect, but say for example, IF you're at 101 kpa ambient and your map under power is 96 kpa. This is approx 5%. So, under this scenario, the intake tract is holding it back about 5%, so you can add 5% to your power number and say you should end up around 460. If you're pulling down to 93, that's 7%, so closer to a gain of 30. Hope that makes sense. It's ricer math, so don't take it to the bank, but will give you a rough idea.

Now, if you change your maf out but not the intake tract, you won't gain anything. you will need to up to 4" all the way from filter to throttle. I won't post a non-sponsor link, but there are sites dedicated to intake hoses. However you get it done is good. Might want to check out the CHRS1313 intake also. That might be a great approach for you.

 

Honestly man. Thank you for all the knowledge your sharing. It's greatly appreciated ?

I looked into the chrs1313. Looks like there is a promod version and a normal version. Either way I'm going to have to go with hood pins and some fab work to get that work.

Im going to see if I can get the measurements before i buy it. Price is very reasonable. It will cost me more to do a dual set up from Spectre.

The only plus side from Spectre is that I can get it to work without any fabricating.

Im gonna try and do some data logging tonight and see what I come back with

 

[quote=Darth_V8r]The math won't be perfect, but say for example, IF you're at 101 kpa ambient and your map under power is 96 kpa.

Okay so I just looked at dash command. My readings in the maf sensor has units of LB/MIN and the map at kPa.

Do I need to convert that?

 

Well I'm an idiot. I realized I'm not reading maf to map. I am reading map at ambient to map at under load ???♂

 

I was just about to answer you figured it out.

Key on engine off should give you ambient on map. Then whatever you got on wot tells you your vacuum at wot

 

Alright man so here's the data I got. Unfortunately I only got to do two pulls on it. I did them in 3rd gear.

Pull #1
4500-5800rpm = 97kpa
5800-7000rpm = 96kpa

Pull#2
3600-4900rpm =100kpa
5000-7000rpm = 96kpa

Ambient fluctuated between 100-101kpa but seemed more steady at 100kpa.

I also had a question. What should he normal intake temps once the car is fully warmed up.

I have all this data. If you want I can try emailing it over to you.

Again, thanks a lot for the help man