Trap speed and intake....

Im interested to see what you guys with intakes are trapping at. It would be cool if you want to list your other mods too, but intake is what i'm looking at.

To make a long story short I goto the track alot and during that time I have done alot of experiments on my intakes. First I had a highflow cat (and all the mods you see below except the MP, FP and Injectors) with a stock airbox and I trapped consistently at 104.X. I mean I probably have 18-20 timeslips to back that up. Then I cut a hole in the bottom of the box and put a 3 inch hose in it and routed that under the nose of the car. My trap increased to 106.2 to 106.6 and I lost 3/10th on my 1/4 mile. This stayed consistent for probably another 10-12 runs that I did over the next few weeks..

Ok...So then I had my car modified with a midpipe, injectors and FP and got an aftermarket cold air box. I went to the drag strip expecting to have a really good trap...guess what? My trap for the next 5-7 runs (over a few trips to the drag strip) was from 104.7 to 107. I only hit 107 1 time, my usual was around 106.6 with a few 104.X and 105.x, you get the picture.

I took my car to dyno tune and it dynoed at 298 to the wheels. Had some timing stuff done and it dynoed at 315.8 @ 12 psi. I figured this had to really help. I went back to the strip a few times and probably got another 6 runs between the two days...My best trap was 108, with my average being high 106's.

I was a little frustrated getting all of these mods and finding out that I was running a little slower with a midpipe even with the identical 60' time AND...I dynoed at 266 HP with the HFC, vs 315.8 with the MP. I decided my problem had to be airflow to that box. I looked under the car and tried to visualize what is going on....I looked underneath the car where the air comes in and found that 90 pct of the air is not going to go into the intake. It will go past the intake under the car. If you notice the air would have to go in an upward direction to get into the intake, cause the front bumper is in front.

I took something identical to the large intercooler hoses, and routed it from under the nose of the car to the entrance to the intake so it routes air into the intake. I ran 3 runs and trapped at 110. I made some more enhancements and believe I will trap 112 ish the next time I go.

I took a hair dryer and placed it infront of the car before I put the air-hose in and felt very little air in the intake. Then I put the hose in place and felt a ton of air in it.

Anyway, Sorry about this long drawn out post, but I think someone could probably use this information.

Let me know what you think (other than I have too much time on my hands).


BTW...I am very happy with the cold air box I have, all cold air boxes are designed very similar and will have air flow restriction unless you do some custom modifications.

 

Heat soaked FMIC at 30C

Trapped at 114 on my first run ever

no cats, intake, fmic, street port, pfc, .80 boost

 

hmmm, now i have to figure out how to do this on an r1 w/o blocking the right oil cooler

 

zero banger i have almost the same rwhp as you i have 314.5 and i used to have rx7 fashion cold air box but when i got my greddy fmic i had to get rid of the box and put the filters right on the pipes. anyway my trap speed is usually around 112

 

Street..I'm hoping my trap is at 112 with .85-.90 boost I will run this weekend, hehe.

Yea I forgot to mention I have the PEP model. I made two intakes, 1 is in the front nose where the oil cooler would be, the other is under the mouth of the car to the passenger side, inbetween the radiator and the wheel wall.

 

How much air the 13B-REW consumed even surprised Mazda’s engineers. They blew one up during testing when their engine sucked air backwards through the intercooler and in to the intake. Go read the article at http://www.rx7turboturbo.com/robrobi...ae_article.htm for all the details.

 

ZeroBanger, if you say you trap around 112 how come in your sig you have 16.4@82mph, is that a joke or something, just made me wonder, later.

 

ZeroBanger,

Somehow I got Deja Vu when reading this thread. A couple of questions. 1) Did you remove the foam on the passenger side of the radiator before going with the hose? 2) Did you see much change in boost when swapping the "opened up" intakes?

Adam

 

yea thats a joke, hehe.

 

Adam,

When it was the stock box yes, I removed the foam. There was a big change in boost with the modified stock box. I had to set my power FC duty cycle settings back a bit cause I could over boost much easier. in first gear I would get 7 -8 lbs with my stock box prior to the mods, after I get 9-10 lbs.

with my modified rx7fashion intake I get 10-12 lbs in first gear now.

 

hey zero, are we ever gonna get to see some pics on your 'ram intake' modifications?

 

Ok, I'll take some tomorrow and post them tomorrow night (as long as I dont get stuck at work).

David

 

cool, thanks...
I have some polished aluminum pipes and K&N filters to go on soon and I am fabricating a heat sheild and ducting so anything will help me get a better idea on where/how to duct it