The quest continues... Made 390rwhp and 413 rwtq yesterday at the dyno. Time stop being a dyno queen and hit the track for some real numbers. Hoping for a 12.99 1/4 mile. Rear tires are 285 Toyo R888r, they hook very well compared to the 295 Pirellis I had. Do you gentlemen think 12.99 is possible?

 

Yep, I see a high 12 in your future! If you had LSD you would be heading into mid to low 12s easily...Have your old tires shaved at least, 1/4 tank of fuel max, remove spare, jack, floor mats, anything weighty that might be in the car, take a good crap before going......Old drag racing tricks that work...

 

I also noticed that cone intake filter...That looks like a power robber because it is not sealed from the heat of the engine compartment...Gott'a keep those IATs down...

 

Thanks Viper! Also, I have a heat shield in between the cone and the engine. Aside from that I have a velocity stack with some tubing in my grill that sends external air to the cone. As long as the car is moving, or in the dyno case, has a fan blowing at the front, the air temp (IAT) is the same as outside, maybe 1 degree higher. I have monitored this with scanner live data over several months.

The main thing that I would say contributed to the power gain was the ice tank. 20 lbs of ice fit in there. The intercoolers and lines get very cold to the touch. It actually forms condensate. This cools the boost down a good amount compared to the stock set up. Colder IAT2 will result in added timing, along with the tune, makes for good power. I also recently switched from the 6% pulley to the 10%, even when I dynoed with the 6% I was starting to drop in hp around 5800 RPM (peak was at 5800, ran it up to 6K but it was downhill), I am assuming from the massive amount of heat. With the 10% it would probably be even worse on the top end (although it really wakes up the midrange), however looking at the dyno graph, we pulled all the way to 6100 RPM and the hp curve was still trending up. The icy water mitigates the heat issue caused by the small pulley Take a look at the picture...

 

I would certainly love to see you get into the 12's. Just a quick refresher on some of the basics concerning your car if you don’t mind. How many miles are on the engine and drive train? Does your custom tune change anything in the transmission? Considering the “seat of the pants” feel of a NA 4.2, I have wanted to see what it is capable of on the strip. your’s make me have very happy dreams. One thing I have often debated is the lack of instrumentation. Do you have any way of monitoring what is going on.

One little thought along the old school way of losing weight is to disconnect the alternator for the run. Given how that would effect an old 1969 428 Cobra Jet Ford with a tiny stock alternator with only 40 - 65 amps I would think these autos would draw even more power. Perhaps you could bypass the AC and alternator with a different belt. It would be a pain but??? I know from looking under my hood switching belts would not be fun. It may not even be something you can accomplish at a track.

Also, where are you going to take it to run as fare as regarding altitude and temperatures? I hope you can get video. Good luck!!!

 

Good luck will watch this thread with interest.

Interesting to see your midrange pull comment as that is what I "feel" in my car.

When did you get then ECU tune?

 

Thanks my friend. It'd be awesome if it was na, but this is the Xjr, so it's supercharged. I don't think the tune affected anything with the transmission or shift points, however the torque increase was much more noticeable. I'd say the throttle response was very noticeable as well.

I am in Florida. Usually terrible humidity and hot, but at sea level as far as altitude. The 1/4 mile track in Bradenton is pretty good though as far as prep. The day of the dyno it was about 80°F and 80% humidity. Was actually raining all morning and during a couple pulls. I believe that ice tank really helps with these factors though and will be the key to a decent time. I'll go within the next month.

 

Thanks John. I sent the ECU to the UK earlier this year. I have another video of dyno showing the tune plus cut outs increase. Total added 16 rwhp but rwtq went up by over 50. And like I mentioned, throttle response is much better. Added a bit of timing, and leaned out the pig rich Afr a bit.