I'm getting ready to swap to a 2" TBI so today I ran some data and used the HP calc. in datamaster.

Today I drove around for about 20 minutes. The drive consisted of in town stop and go, some cruising of about 30 mph with an area where I punched it to 60mph.

When I plotted the entire drive data the torque numbers seemed really high in comparison to the HP.

I then decided to plot just the area where I punched it (5-60mph) and the torque was 997 at 430hp @ 4300rpm

Keep in mind this combo made 500+ on a rochester carb but currently it's running on the stock 1 3/8"TBI. I dont believe the stockTBI is capable of supporting those numbers.

Whats your opinion on this? Is the lack of induction allowing that "spike" of hp / torque to skew everything.
It will just about lift the tires off but only for a split second then it settles down... I'm assuming this is due to the lack of induction to support the initial dump of fuel when punching it.

Thanks Brandon

 

that statement makes absolutely no sense to me...but hey what do I know.

 

Not sure why you're relying on this to be accurate.
I'd take it to your nearest speed shop and get it dyno'd if you want accuracy. Then dyno it again after you swap the 2" TB unit.

 

Like I said, I was looking for some GENERAL numbers to base the change on. I'm interested in the opinions as to why the torque readings are so high in comparison to the hp. and weather or not this skew is due to the lack of induction. Typically HP and torque readings are somewhat close in gas applications and mine are obviously out of proportion. I'm not saying the numbers arrived thru datamaster are ACTUAL HP or even torque. But 400 hp with almost 1000 ft lbs torque makes no sense to me... I'm wondering if its the initial ability to make the HP but then the lack of induction falls short of being able to keep it up?

 

Something is wrong... 997 ftlbs of Tq @ 4300 rpms is 816hp. Hp is just a measure of torque @ rpm's.

 

I'd love to see someone lift the front end of their full size pick up especially one with a 350 tbi!

 

Maybe he needs to fix his suspension, lol?

 

Actually for TTS to acurately depict the numbers, you need to factor in the gear the transmission is in and make a pull ONLY in that gear. Most likely the peak torque was recorded in first gear and needs to be divided by roughly 3:1. 997/3.06 = 326 TQ

 

My buddy lifted the front of his 02 chevy 2500 once with the 6.0L gas job. He had those bang-chirp shifts in the auto tranny, and he was pegging it and for whatever reason it picked the tires up right on the highway. Scared the **** out of me!

 

I dont believe any vehicle is capable of lifting the wheels off the ground especially at highway speeds and on street tires. the tires would spin before they grabbed hard enough to allow the gears to walk and pull the car off the ground.

 

Have you ever seen truck drags? they never get off the ground and they have like 1400trq deisels. I've never even seen a rock crawling truck with super low gears do that, its hard for me to beleive a DD fullsize reg weight truck could lift up the front end even with alot of power, their just too heavy. You would need to have the most solid suspension and tune your engine to have all the torque on the low end then MAYBE i could see it happening. Not saying it can't happen but you would need extensive work and alot of power to do that. I use to drive a 2006 gmc 2500 duromax at work with about $40,000 in the drivetrain and engine. It has around 600hp and 800trq and it didnt seem very fast at all but damn could it pull sh*t.

 

Apparently you haven't ever seen or heard of Dave Jarvis. He has a mean 406 in a Fullsize Van, that is driven to the track in Drive on Pump Gas, then he runs it in Drive on the Track on pump gas.

http://youtube.com/watch?v=WRKISmmkYww

 

Thanks Fast. That seems to make since now. I'll look into the setup feature too. Something may be off there also.

BTW. Since this thread did get off topic I want to comment.

8 years ago I had a pretty nasty small block 355 4 gear in a 2wd 70/pu...DAILY DRIVER! Running street tires and stock coil suspension. EVERYONE would say the same thing...not possible....WRONG!!!!! The local auto parts store said they would give me a $100.00 store credit if I could lift the front tires....They met me at the track one weekend and now have an 8 1/2" x 11" framed on their wall with the front tires nearly 24" off the ground!!! Nothing fancy...it was basicaly a garage built motor, tranny and rearend. A daily driver... driven to the track on weekends, on pump gas with street tires, naturally aspirated.
So to clear any confusion or misconception... IT IS TOTALLY POSSIBLE!!

 

Fast...That van is NASTY! He was breaking loose half track! Granted he was on spray and had a decent tire but you proved the point I was making!

 

To that I'll add: the driver's car has a 4L60E, so that means he's seeing torque converter multiplication briefly in 1st gear (when the input/output trans speeds have max difference, and after each subsequent gear change. These appear as spikes in a chassis dyno plot.