Zex direct port on 7bolt.

[scottsee]

Hi, I'm wanting to buy a Zex direct port kit for my 2g. I am planning on tapping the runners on my 2g intake manifold.

I'm installing comp2 cams and ARP head studs before spring, so I figured that would be a great time to plumb in the nozzles into the manifold sense it will be off. I had a couple questions I was hoping someone could answer for me, or at least point me in the right direction.

Will an OEM H/G with ARP's ok. I know Commetic would hold better I just dont want to mill the head to ra-30+ finish to get it to seal right. I bought one about a year ago, but I really don't want to haste with it. Besides, if something were to blow I would rather it be a gasket.. Has anyone had good results with OEM on 75+ shot?

Using the Zex direct port kit, would the fuel solenoid get its feed from my Aeromotive?

Is there a formula for the extra flow rates required from the fuel pump to keep BFP up? Any link would be extremely helpful. All I could find was a mention of the extra fuel pump requirements, but no formula. I'm trying to figure out if I can support maxing out my evo3 (30psi) with nitrous (50-75-100 shot) on a single r/w 255hp pump. I just can't seem to find the flow requirements from the fuel pump to keep up with nitrous. I imagine it has to do with the solenoid/jet and might be manufacture specific, but any key in on this would be helpful..

Thanks..

 

[Kevin Jewer]

People have made 500-600 whp on the stock composite gasket and ARPs. I don't know what my fat ass 2g was making on it's final setup, but times trap is in my sig, and I was moving 64 lbs/min on a calibrated sensor. I'm guessing you'll be fine.

I get the fuel supply for my peiced together kit from the aeromotive, very clean solution IMO. 6an to 4an reducer, then a 4an line to the solenoid. Like it's meant to be...

Most calcs and things you'll find require BSFC and are pretty worthless for the average DSMer that hasn't measured that for his car. I prefer to just treat added power from nitrous like it was added power from more airflow. The end result should be very similar, assuming you jet the fuel to maintain a similar AFR to what you normally run. For example, I choose the jets so that when the nitrous comes on my AFR barely changes. Fuel flow through the nitrous jets will correspond with the increase in power it provides. In other words, for a 75 shot, add 8 lbs/min airflow. With a EVO16g, that brings the total capacity up to 50 lbs/min. For 100 shot, add 10 lbs, etc. Then size the pump for that number. A 255 rewired, even a low pressure version, will be fine. Rewired 255LP has been proven to support a little over 60 lbs/min, based on data I collected and posted on my site. This certainly seems to adequately cover what you plan to do, and you plan to run a HP pump. One other factor that helps is that a EVO 16g with cams will taper to a little over 20 psi when maxed out, so the pump doesn't have to run much pressure. At an end result of around 63 psi the 255 pumps have enough headroom for a good bit of nitrous.

This is the setup I am currently running. Maxed out EVO8 16g (42-43 lbs/min) plus a 75 shot, on a 255LP. AFR holds to my target all the way to 8k RPM.

 

[scottsee]

In other words, for a 75 shot, add 8 lbs/min airflow. With a EVO16g, that brings the total capacity up to 50 lbs/min. For 100 shot, add 10 lbs, etc. Then size the pump for that number..

Perfect. Thank-you kevin.