Last night I ran at atco and finally broke into the 11's
the timeslip is as follows

60' 1.666
330' 4.940
1/8 7.652
mph 90.24
990' 9.924
1/4 11.952
mph 114.45
This was my best of 2 runs and I spun off the line and hit rev limiter in 4th right at the end of the track. I can wait to get lightweight rims and slicks. Mid 11's should be acieved before the end of the year.

 

Awesome :hail: Another 219/SR/AFR 190 setup in the 11s!

 

thats impressive..congrats :hail:

 

Congradulations.
Those are some killer 60 ft times. Are you not already on slicks? Darn good for DRs if that's the case.

 

Congrats!!! VERY nice!

 

Way to go. Awesome results!!!

 

What tire are you running? Good short time for a stick. I'm impressed.

 

Cool! Now, it's time for a vanity plate and to update that sig.

 

im running on 26X11.5X16 et streets, i think if i runs a 28X10X15 full slick i can bring the 60' down to 1.55 and the the et should drop to around 11.6 when i get all the bugs worked out, and then hopefully a 11.4 in cooler weather.

 

Where did you get your HT383 shortblock, if you got as a shortblock, and how much $?

Great times.

 

Ahhh Yes another happy friend.

Way to go Johnny! With those 28 tall tires you will hook much better like I described on the phone. Many of my buddies have been not so much getting better 60 times, but rather more consistant one.

Just for the folks you should mention what your previous times were.

As I said before, with some cooler weather you will be in the mid 11s.

I would like to see your time slips, send me an email after you run it with the new slicks. I can help you out with your 60times most likely with some more tuning.

Good Job! 11s are fun to get. :hail:

 

whats killing that 60 ft. time is the 4in. mufflex cat back. If he switched up to a 3 or 3 1/2 in cat back, he would regain his lost torque. That 4in. sewer pipe is overkill and hurting HP and TQ (and yes, it was proven on a dyno at MTI in Houston). Any single in - single out 3 or 3 1/2in system will improve your results. Just my $.02 !

 

Wow a 4" exhaust hurts a big cubed car more than it helps? Do you have a link or more info about the test at MTI, Mike? I was actually thinking of going with the 4" Mufflex system. Maybe I'll reconsider.

 

definitly switch back to a 3 inch exhaust You will gain in torque area which will most likely make the car lauch differnet so you may spin more which will deinitly make you hit the rev limiter before the run it over in 4th gear. unless you got a taller tire though. moving up to the 28 inch tire will help you trip the lights right where your engine is maxed out in HP. try it and let us know.

 

That's interesting about the 4" system being too much pipe for the cars. I run a custom 3" Y pipe that connects after the transmission to a single 4" pipe and single 4" Spin Tech muffler. And before with a LTR 383 my car had so much torque off idle, it was great. I mean just mashing the gas to about 2/3 throttle would spin the tires. I am not trying to argue that the 4" is better, I just find it interesting that some of you have had poor results with a 4" exhaust. Oh well, good knowledge for later reference anyway...

 

Thats very interesting, do you have link to the tests?

 

I don't think anyone has "poor results" with the 4" pipe, it's just that when you are launching at 2500RPMs with slicks you have much more use of your torque. The larger pipe apparently cuts down the torque enough to be noticed under those circumstances.

With a LTR 383 you can pretty much spin street tires with ANY exhaust on there.

 

I know I’m not the only one that’s run uncapped headers and large dual exhaust systems. I can tell you, as anyone else that’s tuned and built race cars that uncapping the engine and running larger exhaust systems usually helps produce torque in the majority of combinations - even at this power level. I can’t say always due to the many individual parts that could be used to make an almost exponential amount of combinations. However, usually if a car with this type combination and power level slows down going from a single 3” to a single 4” pipe, it’s because the tune was better for the smaller exhaust system.

Granted, at this power level,,, there might not be enough power difference to warrant the additional cost,,, adding that the worst case scenario would be a POSSIBLE reduction in fuel efficiency. Still,,, a single 4” pipe surely would not slow this combination down. I’ve run similar carbed combinations with dual 3.5” exhausts that gave a slight performance advantage over the same manufacture’s dual 3” system. With no changes to the “best tune” for the dual 3” system, the dual 3.5 exhuast is a little sluggish down low. However after squirter, pump cam, and jetting changes – and sometimes re-curving the distributor, the low end and then some is back. I’ve personally NEVER been involved in an exhaust swap (and I've been involve in a number of them) that larger pipes slowed the car down,,,,, after being properly tuned.

 

Hmmm....Kevin, that's really what I wanted to say, I just didn't want to get lambasted and told that I'm full of bs. Like I said, I'd like to see some real proof that a larger exhaust would hurt dyno #'s or more importantly track times. Maybe it's the muffler that becomes the restriction when bigger pipe(s) are added. That could be why some don't see a gain when adding 4" exhaust.

 

Kevin is 110% right, you just have to tune it for the new airflow charictaritics. Mine actually needed lesser amount of acceleration enrichment with dual 3" pipes.

 

Right on Rick. I've been wondering about MTI lately and their tuning abilities. I'm talking about the instance mentioned where they lost power with a 4" exhaust. I've also wondered about them ever since MTI mysteriously lost power in the GMHTP rebuild of Thunderchicken. I wonder if they know what they're doing sometimes. I'm not trying to knock them, cause I know they put out the best Gen III packages in the country. I just don't understand how you can lose power with a big ci motor and bigger exhaust.

 

Guys,

This is with respect to the talk going on about the "too large". This is not intended to start any arguing, I just want to share with you all my experience with my car and my exhausts.

When I first got me car together it ran with a 2 1/2" fuel non mandrel bent exhaust through flowmasters down to 11.4@120 MPH. That same day we dropped the entire exhaust off the car and ran straight out the headers...it immediately ran 11.1X@123. Just as we figured the smaller exhaust was choking it off later in the run. My 60' times remained identical and actually gained a few 1/100, but probably just from the weight loss if anything.

Now on a seperate occasion, Corky and I ran different headers on his car. He had prior to that a 3" duel mandrel bent exhaust running through flow masters. This day he first ran with his 3" setup and 1 5/8" headers, as a basline. In the pits his exhaust was dropped and he ran with this 1 5/8" headers open,. as expected no change in his ETs showing the 3" duel mandrel system even with the added weight, which isn't all that much did not effect ETs. He then in the pits again, put my 1 3/4" headers on the car. Taking into consideration the DA as best we could, we figured that yeilded at a very best .06sec better ET.

Now I guess what I am trying to illustrate here is the fact that our larger motors are not effected at all by not running any sorta exhaust, basically eliminating any backpressure.

So I can't see where anyone would loose power/Torque with a better or overkill exhaust.

Furthermore, 90% of the strip only cars run open headers. If there was an advantage to running exhaust systems to build up backpressure, I think more than 10% of the people there would have them on. Since most people there want to see how quick they can get.

This is just my information and experience I thought I would share with you. If you really want to see if your car runs better with and without the exhaust just run open headers after a few baseline passes at the strip. Just be sure to figure in the DA differences.

 

that is the most craziest thing I heard on this board yet he slowed down with that 4 inch exhaust come on now do any of you guys think before you type duh
if anybody slowed down by going bigger exhaust it was from going lean not from too little back pressure just like ski said if people ran faster with some back pressure the guys at the drags would be doing it
some of you guys are big but holes I swear but you do make me laugh allot

 

THat's not very nice, but very funny!!!

 

Add my vote that "backpressure is BS". Backpressure kills TQ/HP, it doesn't make it. Where I come from, backpressure = restriction = lost HP.

There are differences between different headers primary size/lengths, and sometimes there can be gains from running a smaller primary tube at certain rpm ranges. But this is more applicable for smaller engines that don't rev high. But as the cubes go up, bigger primaries tend to give the better results.

But that's a different issue than running a smaller exhaust system. When you have a smaller engine, you may not find any significant gains by going to larger exhaust system (other than it sounds louder). But you won't run slower.

If backpressure was good, everyone would be pounding potatoes into their exhaust systems. As Ski & Corky said, people tend to run faster with their headers uncorked.

 

glenn hold on ill be right back im going down the store for some potatos

 

Corky, make sure they are the "new whites". They are good for 10 extra HP over the russets. The reds are over-rated IMO and not worth the extra cash.

Wrap a few extra in tin-foil, place them on the base manifold between the runners and you can cook dinner while racing. You can also offer it to the ricers as an alternative.