I am looking for trap numbers from people with Vortech and ATI superchargers.

Thanks

 

I went to the track for the first time in my life, two weeks ago. I was trapping in the 116mph range (street tires).

Next week, I will have a DR setup. With the better traction I hope to be full throttle in second gear? If so, I am expecting 118mph or better.

:cheers:


[Modified by hogurt, 8:17 AM 5/25/2003]

 

Please list traction comments, ambient conditions and altitude to go with the trap speeds. :lurk:

 

ATI D-1SC @ 8lbs Boost

Best run: 12.58 @ 122mph
60 ft = 2.12
82 degrees @ 6000 ft altitude
Denver, Colorado

 

Main reason I am interested in trap speeds is to see for example: how a 600rwhp ATI car will run with a 500rwhp MTI 427. I have heard a lot of area under the curve arguements but have yet to encounter any s/c cars on the road.

 

My runs were horrible.

I had to completely get out of the throttle on the shift to second gear. . .lost traction. My best 60' time was 2.47 :U .

I don't really know how altitude or weather impacts us here in St. Louis. :confused:

My opinion is simple, "there is no replacement for displacement"! If my lil' 350 should blow, you can bet I will be going with the big block!

In a straight line run, I would assume that the car with the most HP will win. However, I also understand that you are going to be running times where the entire win/lose will come down to the driver! Furthermore, if there are repeated runs, the FI car will likely suffer more because of the engine heat. . .less efficient boost!

:thumbs: Let us know how things turn out.

 

Well if that's the case, then when considering such comparisons (IC centrifugal blown vs. big cube high CR N/A) the 1/4 mile performance vs. peak output has to also consider the following:

1.) Output to weight ratio: IC centrifugal kits add on the ORDER of 100 lbs. of curb weight (mostly on the wrong end of the car when it comes to RWD vehicle launch traction). Hence even if a blown setup sweeps through the same avg. power through the 1/4 mile as an N/A setup (assuming similar traction and gearing), the blown setup would be at a disadvantage. ~100 lbs. is not a small matter and everyone except seasoned/observant drag racers never appreciate what a 100 lb. penalty can do.

2.) Conditions not measured by dyno: Blowers enact load on motors which means more air/fuel (--> heat) to maintain an engine at a given idle speed. This means after a long cooldown, the supercharged setup will have more heat transfered to the motor and coolant than an N/A engine will while it's idling in the pits to staging (assuming moderate thermostat rating, equal cooldown period, and both N/A setup and blown setup wait the same period to stage from first firing up their engines). On the coolant temp gauge, that could mean the N/A setup by the time it is staged may have the coolant temp gauge buried on the low side, while the S/C setup is a somewhat higher.

Plus there's trace heat sources from the slowly spinning blower and of course there is no cross-flow to the IC when you're idling in the pit lanes. High underhood temperatures sink plenty of heat into the lengthy metal pipes (of centrifugal IC setups, less so on air/water ICs since air/water IC'd setups don't require long pipes to position the IC in ambient crossflow) and possibly the IC when you're idling for long periods in the pit lanes.

Reason #2 will likely make a 100 rwhp advantage for a blown IC belt-driven supercharged setup over an N/A setup on a dyno really reduced to a 70-90 rwhp advantage on at the dragstrip.

Reason #3: Lastly, the powerband debate for centrifugally S/C'd setups FOR DRAG RACING is not so much what is lacking down at low rpms (since so little time is spent there), but how high one can go to properly take advantage of the powerband without overboosting or running into valvefloat/excessive bearing wear. More specifically, on non-CVT transmissions, the ideal shiftpoint for drag racing is one that is 10-15% above the peak power rpm to make the most out of powerband (e.g.: tire to surface thrust at upshift rpm is equal to tire to surface thrust at shift recovery rpm). Well if a centrifugally S/C'd setup makes peak power at 6500 rpm and you set the rev limiter at 6700 rpm (due to put a cap on boost and prolong valvetrain/bearing life), well one is likely missing out on the meat of the powerband. This is the argument going around in Nissan/Infiniti forums on why the '00-'01 Maximas and '02-'03 Q45s don't run as fast as weight/peak hp ratio would indicate; their peak power rpms are 100-200 rpm below the redline.

Combining Reasons #1, #2, and #3, this may stop people from scratching their head when the peak rwhp #'s of a centrifugally blown S/C setup does not quite meet their expectation. Still considering the relatively low cost of belt-driven IC'd setups to big cube conversions, the belt-driven IC'd setups more than hold their own in bang for the buck while maintaining excellent drivability (motor kept stock and tuned right).

 

That's good stuff! :yesnod:

 

Thanks and...MAY THE BOOST BE WITH YOU!!! :flag

 

wow long answer

 

Kumy,

I hope to trap 130+ with my setup. On the bottle I trapped just below 130...a scorching 129.6 but I am making about 75-100 more horses. I am sure alot of other factors will come in to play (as mentioned), but I am curious to see.

BTW,
Want to buy a blower with installation and a tune?

 

No man, I am happy with my engine right now. Just gonna throw a lil 150 shot on it later in the summer. I'm having some transmission issues right now + I really need a bigger cam in my car. I havent really got to test the car out since I got it back. Looking forward to racing you something soon. :D

I want to trap close to 130 on motor.

When I was looking to replace my blown motor, I strongly considered the Vortech or ATI units but I needed forged internals this time and I couldnt afford to do a forged internals motor and a supercharger with the 8 rib setup etc.

I havent seen any Vortech or ATI cars run in person so I am really curious and interested to see yours. Did you ever dyno it with the belt holding?

What blower are you selling BTW?


[Modified by kumar75150, 12:43 AM 5/26/2003]

 

I am just seeing if you were interested in the blower I have on my car. I am toying with selling it!

I tried to go to the spot Sat, but it was raining! Just let me know anytime you want to check it out!!!!!!

Also if interested I would be willing to help you install some NOS. I have 2 kits you know!!!!! Just let me know (unless you have a special kit you were looking for!)

 

I'll call you later this week. I am hoping to have my car fixed this Tuesday (putting a Mcleod Adjustable Master in). Otherwise, we are gonna drop the tranny and its gonna be out for a couple weeks again.

There is the CC meet tommorrow night (dont know if I will be there) and Chucks on Wednesday night (hope to be there).

I'll talk to about the nitrous after I get my poopie together and kick some butt on motor first.

 

send me a PM on the CC meet....what is it?

Let me know, I am ready to get this beast on some test runs!

 

Best numbers from my current setup are: 11.14 ET, 126 MPH, 1.57 60'
still testing and "working it down"

JR :thumbs: :thumbs: :thumbs: :thumbs: :thumbs: :thumbs: :thumbs: :thumbs: :thumbs: :thumbs: :thumbs: :thumbs: