DIY cai?

synolimit · 08-03-2013, 06:46 PM

Quote:

Originally Posted by Jordo!

I did the exact same thing and found that the vibrations make a huge difference on the dyno.

The airboxes don't move around nearly as much as you think relative to having nothing clamping the intakes down.

Take it to the dyno and see for yourself... I've got no problem with being proven wrong...

On a related note: I have the MAF bases cut from the airbox (i.e., plastic tube with base) and would happily sell them to you if you don't want to cut your airbox up. PM me if you want them. I can provide pics if you want too.

Well I agree with them not moving much because they don't move under wot. When the motor rocks back under load it stays there. The MAF should see no change. Now during a shift or let off, yes, there should be huge swing in the pipe because the motor relaxed. Unless you're seeing voltage changes on the street and messing things up, ill never know. I don't do dyno's. they are pointless to me and I hate them. I use road dyno software that can calculate the weight of the car, aero dynamics, wheel diameter size, tire size, looks at wot, speed, rpm, etc etc and can tell you a real, true hp and tq since it can calculate the time it took you to go from say 2000 rpm to 7500 rpm. Its actually accurate because you have real wind pushing against you, ambient temps and not 300 degree dyno rooms, and real world roads. Only thing you must do is get all the info right, wheels, weight, etc. also find a flat road and dyno in both directions and average runs for a correct hp and tq. Normally these run like or lower than a mustang but is proven with 1/4 times and trap speeds.

Thanks for the heads up though. We'll watch the volts.

luigi90210 · 08-03-2013, 08:03 PM

Quote:

Originally Posted by synolimit

That's going to increase price no? The stock MAF is free and the pipe I got was $23 shipped. Any links?

well if you want an effective DIY intake, you will at least need post MAF Tubes to help with flow

with the intake, it costs about the same as HPS tubes with free shipping and including your extensions it will cost you around $150 give or take if you need new piping or not(i dont think you will but there is a chance you might)

plus it will lean things out mechanically so you might make as much as stillen G3s(its 2.75" piping with a 2.5" Maf adapter which is bigger than the stock tube)

Red Shortram Air Intake Kit Infiniti 08 13 G37 07 08 G35 Sedan RAM Cool Dual V6 | eBay

there are cheaper ones on ebay as well, i dont know the intake size but i have seen other knock off intakes go for $90

kenchan · 08-03-2013, 08:46 PM

Use your brain elsewhere. Just buy the post maf tubes and kn drop ins.

synolimit · 08-03-2013, 09:29 PM

Quote:

Originally Posted by kenchan

Use your brain elsewhere. Just buy the post maf tubes and kn drop ins.

Not worth it to me.

synolimit · 08-03-2013, 09:35 PM

Quote:

Originally Posted by luigi90210

well if you want an effective DIY intake, you will at least need post MAF Tubes to help with flow

with the intake, it costs about the same as HPS tubes with free shipping and including your extensions it will cost you around $150 give or take if you need new piping or not(i dont think you will but there is a chance you might)

plus it will lean things out mechanically so you might make as much as stillen G3s(its 2.75" piping with a 2.5" Maf adapter which is bigger than the stock tube)

Red Shortram Air Intake Kit Infiniti 08 13 G37 07 08 G35 Sedan RAM Cool Dual V6 | eBay

there are cheaper ones on ebay as well, i dont know the intake size but i have seen other knock off intakes go for $90

Yeah I'm not messing with larger pipe. $10 says tuning will be a must, that short MAF housings not enough. Plus, now takjak has turned me onto the silicone having less heat idea. The less metal the better. He'll if I could make silicone tubes I would! $100+ is a ******* joke for those tubes!! If I can buy 6 couplings and not go over $40, no way them post tubes should rape your *** like that.

luigi90210 · 08-03-2013, 11:47 PM

Quote:

Originally Posted by synolimit

Yeah I'm not messing with larger pipe. $10 says tuning will be a must, that short MAF housings not enough. Plus, now takjak has turned me onto the silicone having less heat idea. The less metal the better. He'll if I could make silicone tubes I would! $100+ is a ******* joke for those tubes!! If I can buy 6 couplings and not go over $40, no way them post tubes should rape your *** like that.

could you explain why it would need to be tuned?

i believe they are knock offs of either the K&N SRI or the Takeda SRI(im leaning more towards the takeda because of the size and style)

i suggest looking up Modshack's SRI

he already messed with silicone tubes and compared them to post maf tubes, they are basicly the same iirc

synolimit · 08-04-2013, 12:51 AM

Quote:

Originally Posted by luigi90210

could you explain why it would need to be tuned?

i believe they are knock offs of either the K&N SRI or the Takeda SRI(im leaning more towards the takeda because of the size and style)

i suggest looking up Modshack's SRI

he already messed with silicone tubes and compared them to post maf tubes, they are basicly the same iirc

With such a small width MAF section and so large before and after, I can promise the voltage will drop. A larger tube drops volts so the ecu will think the motors at a smaller flow rate and will add less fuel than whats needed, run lean, it blows up. Typically a MAF section needs to be at least 9" long and nice and straight.

luigi90210 · 08-04-2013, 01:23 AM

Quote:

Originally Posted by synolimit

With such a small width MAF section and so large before and after, I can promise the voltage will drop. A larger tube drops volts so the ecu will think the motors at a smaller flow rate and will add less fuel than whats needed, run lean, it blows up. Typically a MAF section needs to be at least 9" long and nice and straight.

it actually provides more velocity than a straight through pipe would

Quote:

Originally Posted by Modshack

I'll do it eventually. I'm designing more for Under the curve driveability than I am for a few HP at RPM's I rarely spend time at.

Hard to say. It looks like they squeeze the pipes at the MAf mount area, but to what internal diameter I don't know. Necking down the pipe and then expanding it again does improve velocity (like a venturi) and could provide some leaning and more power depending on the ID. The placement of the MAF inside the tube will have an effect also as air flow through a tube is faster in the center than it is toward the outside. I'd tend to doubt that 20hp number though..

synolimit · 08-04-2013, 10:37 AM

Quote:

Originally Posted by luigi90210

it actually provides more velocity than a straight through pipe would

I'm not in aero so id have no idea unless i saw hard data but the ecu isn't going to be able to compensate that much MAF volts in a rise or fall. Once out of the parameters of the ecu good luck not blowing it up. The car isn't turbo'd so there'd be no reason to go any larger than 2.34" ID. Since I've seen some cars run mid 13's AFR I wouldn't F with that ****. Not unless you're at the tuner tuning at that time. If stillen thought it was a good idea they'd of done it! But since they use 2.34" ID from just after the filter all the way to the TB, I'd say they figured it out.

Jordo! · 08-05-2013, 04:19 PM

Quote:

Originally Posted by synolimit

Well I agree with them not moving much because they don't move under wot. When the motor rocks back under load it stays there. The MAF should see no change. Now during a shift or let off, yes, there should be huge swing in the pipe because the motor relaxed. Unless you're seeing voltage changes on the street and messing things up, ill never know. I don't do dyno's. they are pointless to me and I hate them. I use road dyno software that can calculate the weight of the car, aero dynamics, wheel diameter size, tire size, looks at wot, speed, rpm, etc etc and can tell you a real, true hp and tq since it can calculate the time it took you to go from say 2000 rpm to 7500 rpm. Its actually accurate because you have real wind pushing against you, ambient temps and not 300 degree dyno rooms, and real world roads. Only thing you must do is get all the info right, wheels, weight, etc. also find a flat road and dyno in both directions and average runs for a correct hp and tq. Normally these run like or lower than a mustang but is proven with 1/4 times and trap speeds.

Thanks for the heads up though. We'll watch the volts.

Dynos are not pointless. They provide a method for quanitifying engine output meaningfully. Poor interpretations of their readings abound, but they are far from pointless.

So long as they are clamped down, it should be fine.

Any interest in buying my MAF tubes so as not to have to hack up your airboxes? I can provide pictures later if you might be interested. They are exactly what you will have to create on your own...

EDIT: I have better pictures somewhere on my computer, but here's an example of one of them (don't think I have the filters anymore)

http://www.the370z.com/attachments/i...take-proj4.jpg

Its the exact same pieces you will have to cut from your own airboxes. These are already cut and sanded. Make me an offer and they're yours.

synolimit · 08-05-2013, 08:32 PM

Quote:

Originally Posted by Jordo!

Dynos are not pointless. They provide a method for quanitifying engine output meaningfully. Poor interpretations of their readings abound, but they are far from pointless.

So long as they are clamped down, it should be fine.

Any interest in buying my MAF tubes so as not to have to hack up your airboxes? I can provide pictures later if you might be interested. They are exactly what you will have to create on your own...

EDIT: I have better pictures somewhere on my computer, but here's an example of one of them (don't think I have the filters anymore)

http://www.the370z.com/attachments/i...take-proj4.jpg

Its the exact same pieces you will have to cut from your own airboxes. These are already cut and sanded. Make me an offer and they're yours.

I was kind of hoping to buy some but only to have extras incase maybe I could put kits together for other people. That way they'd be cheaper since I'd buy so many couplings and length of pipe. But I'm sure I'd have to pay for a vender license here and that probably wouldn't be worth it because that and I've seen one guy ask $200 for his in boxes. At that price I'd never get my hands on enough.

synolimit · 08-09-2013, 08:01 PM

All done

takjak2 · 08-10-2013, 04:21 PM

Quote:

Originally Posted by synolimit

All done

Pics?

synolimit · 08-10-2013, 07:31 PM

Quote:

Originally Posted by takjak2

Pics?

First post.

luigi90210 · 08-10-2013, 10:41 PM

i might do something like this in the near future if i decide to go with LTI

good write up

08-03-2013, 08:46 PM	#18 (permalink)
kenchan A True Z Fanatic Join Date: Aug 2009 Location: N/A Posts: 76,801 Drives: N/A Rep Power: 141521	Use your brain elsewhere. Just buy the post maf tubes and kn drop ins. Japanjay likes this.

08-09-2013, 08:01 PM	#27 (permalink)
synolimit A True Z Fanatic Join Date: May 2013 Location: Columbus, OH Posts: 5,051 Drives: 2013 Silver 370z Rep Power: 3389	All done __________________ 13 370z-

08-10-2013, 10:41 PM	#30 (permalink)
luigi90210 A True Z Fanatic Join Date: Apr 2012 Location: San Diego CA Posts: 1,103 Drives: Classified Rep Power: 15	i might do something like this in the near future if i decide to go with LTI good write up __________________ SOLD 370z New Car:classified DD:2011 Mini Cooper S stock