Helo58

Early on into owning my F, I noticed that the previous owner had installed a K&N Typhoon intake with cone filter with a Borla exhaust. I took it to the track (Rockingham Dragway - 420ft altitude) in this configuration and ran consistent 13.20s @ 113mph with 2.0 60' times.

At the time here on the forum, there was a lot of talk about the validity of company's claims to HP added by aftermarket intakes. K&N still maintains on their website gains of 22 horsepower. By consensus, the ISF community agreed that cone intakes make no more power than the stock intake due to heat soak etc...

After reading this, I searched for, found, and installed a stock intake box with the afe dry drop-in to maintain the stock Lexus eqipment. Returning to the same track in this configuration (at a similar DA) the car consistently ran 12.80s @ 110mph with 1.85 60' times. I immediately determined that the stock airbox made more torque but lost horsepower on the top end.

Most recently, I went to the same track (similar DA) and ran 13.00s @ 110mph with 2.0 60' times. The only change, was brand new Bridgestone S-04 tires. The Bridgestones hooked perfectly with no traction issues. But it should be noted that they weighed more (+4 per front and +5 per rear - 18lb total) than the PSS.

Takeaways... Based on computations for trap speed and vehicle weight, the change in trap speed reflects the 22 horsepower horsepower claimed by K&N. It is my opinion that the K&N DOES make more horsepower but at the expense of low rpm torque. I love the lower ETs but I hate the loss of trap speed and top end. As for tires, if you are interested in ultimate performance, TIRE WEIGHT DOES MAKE A SIGNIFICANT DIFFERENCE. So much focus goes into minimizing wheel weight but very little attention is given to minimizing tire weight. I have read that Porsche claims 1lb of wheel/tire weight = 8lb of car weight. I can't substantiate this, but it seems fairly accepted in many forums. Furthermore, the rule of thumb is -90lb = -0.1s in the quarter mile. With those rules of thumb in place, I am pulling an extra 144lb (rotating an extra 4.5 per wheel) down the track losing 0.16 seconds. This bears out in my 1/4 mile times above substantiating the rules of thumb and explaining the loss in performance I am experiencing.

I have noticed that R&R is now using a cone filter in their new intake and claiming horsepower gains, going against the previously accepted knowledge of the forum members. I am interested in how their new intake will perform at the drag strip (specifically torque). To me any track is a better measure of performance than a dyno. What are everyone's thoughts on these topics?

FFM

A tenth off your 60' generally equals to roughly two tenths off your ET. Your quicker run was likely due to the fact you shaved nearly two tenths off your 60'.

I'm not seeing this proving the K&N's power claims. If anything, the quicker 60' and the stock airbox appears to have aided in your quicker run. Your trap speed on the original run would be a byproduct of the worse traction as well.

Helo58

Agreed, I have read that as well. I think that the heavier tires negated the torque gains I got from the stock airbox by turning a heavier tire. So now I am back to the same 60' times with a 110 trap. It would be nice to have the 1.85 60' time coupled with a 113 trap. It is my thought that trap speed is probably the best indicator of HP I have available to me.

tas02

iTrader: (2)

I've always used the dragstrip to quantify effects of mods since before there were chassis dynos everywhere. So you can guess which I prefer.

I completely agree with your assessment of wheel & tire weight. With the limited options we have for additional power, take more wherever you can get it. Reduced rotating mass also gives a larger number on the dyno.

Is the strip Rockigham the one that has 4 lanes?

Helo58

No, that is the one here in Charlotte. It is called ZMax Dragway and they haven't done test n' tune there but only a handful of times. I don't know why they don't do more because there are only a handful of tracks in NC that offer the 1/4 rather than the 1/8th. My friend lives in Palm Beach and the turn out at their track is awesome. Little to no turnout in Rockingham.

I absolutely destroyed a CTS-Vsport by 2 car lengths 3 times. Granted it is not a proper V, but it does claim to have 420 horsepower 430 lb ft torque. I guess turbo lag and 3900+ lb sucks.

tas02

iTrader: (2)

Less turnout means everyone there gets to do more runs. One of 2 the tracks in my area (Pacific Raceway) is so crowded it can sometimes be 2 - 3 hrs. between runs. The other track (Bremerton Motorsports Park) is the same distance away, requires a $15.00 ferry trip to get to, and charges more to race, but they have better traction and a lower turnout. That's where I go.

4 lanes would get more racers through, though there's likely more liability issues for the operators. I've seen 'em run 4 wide on tv, would def. try it if it was available.

It seems the 1/8th mile is (unfortunately) becoming the standard as property values increase. I much prefer the quarter. It's addictive. I slapped on the drag radials @ 11 pm last Saturday after returning from Hot Import Nights anticipating mid 50's temps for Sunday. Set my alarm for 5 am., but stayed home when the cool air arrived with drizzle.

tas02

iTrader: (2)

As for the RRRacing tuned intake, I may go that route if I see people post positive results. Or I may hold out for the supercharger after seeing a Vortech equipped e92 m3 @ HIN. There was also a supercharged is350, couldn't see the snail on the is as it was under the plastic engine covers.

Helo58

You assume that the operators of the track I was at were on top of things. Tech inspection at this track is very lenient (if not non-existant). As a result, several cars break or leak on the racetrack which then requires cleaning of the track and the subsequent re-prepping of the track. This is in addition to the normal cleanings and breaks. Also, this last time, they opened late, began tech late, and started racing almost an hour late. Once going, they had sensors in the left lane that kept malfunctioning and nobody got 330 or 1/8 mile times. Many were there JUST for 1/8 times. Needless to say in 3 hours, I made 2 runs and that is with only 10-12 cars staging at the time. If there was an alternative, I would certainly check it out!

I would love to go the supercharger route, but I figure by the time I do headers, a tune, labor, and goodness knows how much for the SC, I will be putting a third of the value of the car in upgrades that will actually hurt the resale or not be recouped at the sale of the vehicle. Then you have stuff like the 727 horsepower Mustang GT sold by Lebanon Ford for 39,995 brand new... Crazy not to do this rather than upgrade the ISF.

http://www.roadandtrack.com/new-cars...ngs-for-40000/

ToothDoc

I did a K&N test, vs. stock, vs. NO intake filter. All of the runs were statistically identical. What I was REALLY surprised was the stock vs. no filter comparison. I thought there would be a difference in having an air filter vs. none, but there was no difference. The intake Is NOT the limiting factor. Why do you suppose both I and Caymandive kept our intakes stock? If you do a search, I'm sure you'll find the posts where I did the comparisons.

Helo58

It was not my intent to question anyone else's results and I assure you that I read exhaustively prior to the purchase of my stock intake. It took a great deal of effort just to locate the stock intake and then pay 400 bucks for it. I trusted the input of every source here on the forum. I suppose you left your intake stock for the same reason I went out and purchased a stock one and installed it. I believed what was being posted on the forum from the majority. The only problem is that these results were largely, if not almost completely, based on DYNO results. With there being at least 4 different dyno manufacturers, with different correction factors, pulls taken in 2nd-6th gears, with different CFM cooling fans, with different operators, with different rest or cool down periods, with different calibrations, etc. etc. etc. You may see why I lean towards data with fewer variables from a single consistent source.

When you say "runs," do you mean dyno runs or quarter mile runs? I have time, temp, humidity, pressure, etc. data for at least 10, quarter mile passes during each session. This is a total of at least 30 passes in which during each of the three sessions, only one variable changed. All other variables were accounted for.

The reason I posted this was to get suggestions on possible causes for the 3 mph difference in my trap speed. The reason I mentioned the RR intake is that for their larger throttle body, they are not using the stock airbox. I am not sure why they would change if it wasn't a limiting factor for their purposes.

I know people will disagree with me, but for my car, with my mods, with my data, the intake makes about 25 more horsepower. Nothing else changed. There were at least 500 miles put on the car in each condition before the data was taken, so I am even ruling out the "learning" aspect of the ECU. A three mph difference doesn't sound like a lot, but for a 4000+ lb car and driver in a quarter mile it equates to roughly 20-40 horsepower depending on the exact weight and which calculation you use.

PDP180180

iTrader: (3)

Could your KCLV figures play a part in this? Just wondering if on your faster pass with the K&N your KCLV was higher, could explain the difference??

Did you reset your ECU when you installed the stock intake?

Any other mods between the two runs?

What about servicing, same petrol etc?

All I'm saying is there are numerous factors that could account for a lower speed during a drag run.

Interesting topic though.

tas02

iTrader: (2)

When I chose to buy a JoeZ intake tube & afe drop in for the stock air box, my decision was based on advice from people (ToothDoc & Caymandive) who've posted youtubes & timeslips showing 11 sec. all motor quarter mile runs.

Has anyone without their stock air box run an all motor quarter mile quicker than 12.0?

Helo58

I did reset the ECU, but not immediately before the track. I reset it when I made the change and then wanted sufficient driving cycles between the modification and the track. No other mods were made and I used the same 93 Octane (up to 10% ethanol) gasoline. I know with multiple knock sensors and the complexity of the engine, it could certainly be the KCLV numbers. I am learning about the significance of these now in relation to posts on the RR tune/dyno results. I will keep looking for more info because now I don't know enough now to know how much this value will influence the performance as it relates to trap speed specifically.

I'm not questioning ToothDoc and Caymandive's results. They are obvious and awesome. I love the videos of the ZL1 and the C7. But I don't know the specifics as it relates to data. Maybe they gave them, but there is tons of data all over this forum that would be impossible comprehensively cover it. That is why I tried to be as specific about my situation as I could so that those with input, hunches, or just opinions could chime in. That is all I am asking for, guesses or hypothetical causes. I don't have the answers, I just have the data from my car that points in a direction. I need people to comment on things I haven't considered or don't know about like the above item (KCLV).

Also, I am looking specifically at trap speed not ET. I understand that the airbox, as my car sits, will give me the best ET. I want to know the possible reasons why the configuration with the K&N gave me the highest trap speed (most horsepower).

Helo58

Just looked back at some of ToothDoc's posts and noticed that there were no drive cycles on the ECU after a mod and before taking it to the track. The mod was made just prior to his 1/4 runs. Does this make a difference? Other thread posts indicate that it could.

He also lost 2 tenths when putting the K&N back on after the stock box, as I did, but attributed it to "hot air" being taken in by the filter. I think the stock airbox design creates more torque than a cone filter.

Bigjon3475

iTrader: (2)

Do you have an OBD tool and something like dash command? It would be pretty easy to see what IAT are and compare.