Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI
02-04-2002, 01:32 PM
#1
Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI So Jayson faxed me the dyno's of the car in the exhaust on/open header configuration. We are both not sure why the car is 10-20 below where it should be for the installed equipment. Considering the car ran 396 with stock heads, these LS-6 stg 3 heads have only picked me up 5-10 hp, depending on how you look at it. Oh well.
The difference between hp curves from 5700+ open header vs closed grott-Y and 4" mufflex with Spintech was... 6hp.
I dont think Ive ever heard of a full streetable (catless) Y and catback only costing 6hp.
Now...from 3k-5700 rpm, the cureves were a little more erratic, where the exhaust sometimes cost 0, sometimes 12 hp. At peak torque (4700) it looks like it cost it around 13 lb/ft. But it certainly didnt kill the top end at all... Which really really surprised me. THat Grott Y pipe is damn ugly, and I had assumed that a nice 2x3" going into a FLowmaster D-port coll then 4" to the mufflex would pick me up 10hp over the ugly-*** thing on there now. Doesnt look like there 10hp there to get.
Now the mystery as to why the car is 10-20 down. The car hits peak hp at 5700 and then just stays there until 6700. Im going to look at other Hammercam cars and see if since I am fixating on peak #s, Im missing the important part of the story. Max torque is only at 380 currently with exhaust, 393 w/o. I really should avoid recalling that with the stock heads, it did 382 lb/feet :-/
Anyways...Good Exhaust! Shame its so damn loud.
\chris
The difference between hp curves from 5700+ open header vs closed grott-Y and 4" mufflex with Spintech was... 6hp.
I dont think Ive ever heard of a full streetable (catless) Y and catback only costing 6hp.
Now...from 3k-5700 rpm, the cureves were a little more erratic, where the exhaust sometimes cost 0, sometimes 12 hp. At peak torque (4700) it looks like it cost it around 13 lb/ft. But it certainly didnt kill the top end at all... Which really really surprised me. THat Grott Y pipe is damn ugly, and I had assumed that a nice 2x3" going into a FLowmaster D-port coll then 4" to the mufflex would pick me up 10hp over the ugly-*** thing on there now. Doesnt look like there 10hp there to get.
Now the mystery as to why the car is 10-20 down. The car hits peak hp at 5700 and then just stays there until 6700. Im going to look at other Hammercam cars and see if since I am fixating on peak #s, Im missing the important part of the story. Max torque is only at 380 currently with exhaust, 393 w/o. I really should avoid recalling that with the stock heads, it did 382 lb/feet :-/
Anyways...Good Exhaust! Shame its so damn loud.
\chris
02-04-2002, 01:36 PM
#2
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI BTW...it was a very cool day in Houston when they did these... Correction factor of .93 :-/
The Actual #s kicked ***!
432rwhp/409.4 rwtq
<img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0">
\chris
The Actual #s kicked ***!
432rwhp/409.4 rwtq
<img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0"> <img src="gr_grin.gif" border="0">
\chris
02-04-2002, 02:13 PM
#3
TECH Regular
Join Date: Nov 2001
Location: Plano, TX
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI wow that's interesting. That's wierd that it peaks like that. The only time I've seen that was with a cam'd car runnin through stock exaust, which isn't the case here. Interesting...
02-04-2002, 04:53 PM
#5
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI Jay son is also going to weld in a WB 02 and go through the whole LS1Edit exercise.
The MAFT usually (temporarily, since *I* think it learned it out) got me 15+ hp by going 10% lean WOT. Hopefully with this combination, those 15hp are still waiting, and with LS1Edit, he can get each piece of the band fueled just right.
chris
The MAFT usually (temporarily, since *I* think it learned it out) got me 15+ hp by going 10% lean WOT. Hopefully with this combination, those 15hp are still waiting, and with LS1Edit, he can get each piece of the band fueled just right.
chris
Trending Topics
02-04-2002, 05:49 PM
#9
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI Changed the sig to reflect the current stuff...
MTI says that I can run stock injectors up to 440-450 rwhp no problem. I believe MTI <img src="gr_stretch.gif" border="0"> If you look at everyone out there, many 430+rwhp cars are running stock injectors. When Jayson tunes the air/fuel, I have no doubt he will be leaning it out by aways. That will mean less fuel requested. I dont know what the duty cycle is directly though. None of the folks like Jayson or Nick at ARE think Im running out of fuel. But it certainly was a question I asked.
\chris
MTI says that I can run stock injectors up to 440-450 rwhp no problem. I believe MTI <img src="gr_stretch.gif" border="0"> If you look at everyone out there, many 430+rwhp cars are running stock injectors. When Jayson tunes the air/fuel, I have no doubt he will be leaning it out by aways. That will mean less fuel requested. I dont know what the duty cycle is directly though. None of the folks like Jayson or Nick at ARE think Im running out of fuel. But it certainly was a question I asked.
\chris
02-04-2002, 06:47 PM
#10
TECH Addict
Join Date: Nov 2001
Location: St Louis, MO
Posts: 2,551
Likes: 0
Received 0 Likes
on
0 Posts
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI Maybe you need a new fuel filter since the car had some old gas (possibly gummy?)
Just a WAG.
Eric
Just a WAG.
Eric
02-04-2002, 07:27 PM
#11
On The Tree
Join Date: Jan 2002
Location: Dallas area
Posts: 148
Likes: 0
Received 0 Likes
on
0 Posts
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI Eric's idea isn't bad...be worth trying. I'm just trying to think of reasons it would just lie flat like that, and fuel is a big one. But I am by no means a guru...i would trust MTI too! <img src="gr_images/icons/wink.gif" border="0">
02-05-2002, 02:38 AM
#13
TECH Enthusiast
Join Date: Nov 2001
Location: Houston / Dallas
Posts: 623
Likes: 0
Received 0 Likes
on
0 Posts
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI Mine is peaking at 5700 and staying flat also, if you find out what the deal is let me know!!! <img src="gr_grin.gif" border="0">
Oh well, the current numbers in the sig arent bad at all. I will be changing my exhaust setup around completely this weekend, should make for some good info.
Oh well, the current numbers in the sig arent bad at all. I will be changing my exhaust setup around completely this weekend, should make for some good info.
02-05-2002, 10:49 AM
#14
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI Yeah, I noticed you were selling the Grotts... Heresy? ;-)
I'll ask MTI if its worth s's n' g's to put a fuel pressure guage on the rail during a couple of the dyno runs while Jayson is LS1Edit'ing it. I really dont think fuel is the issue... and the MAF is ported "well", so the MAF is definitely not running over 410 cfm. Im kinda stuck in a holding pattern until I see what WB tuning does. Then I'll revisit the whole dealio.
\chris
I'll ask MTI if its worth s's n' g's to put a fuel pressure guage on the rail during a couple of the dyno runs while Jayson is LS1Edit'ing it. I really dont think fuel is the issue... and the MAF is ported "well", so the MAF is definitely not running over 410 cfm. Im kinda stuck in a holding pattern until I see what WB tuning does. Then I'll revisit the whole dealio.
\chris
02-05-2002, 11:24 AM
#15
LS1Tech Co-Founder
iTrader: (34)
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI I saw a car two years ago do that because it had too much lifter preload from pushrods that were too long... Had 7.450s instead of 7.350's.
02-06-2002, 12:26 AM
#16
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI Yeah, I talked to both Jayson and Jeff at MTI about the chance of lifter preload. They assured me that that was somethign that was checked. I do not believe that my heads were actually decked. The LS6 heads at 10.5:1 were enough for me here in WA/OR where we only get 92, and sometimes its ethanol/oxygenated, both of which f%^& up the power potential a bit. I dont know how the base circle of the Hammer Cam is compared to the Hotcam I had in there before. And I guess I am pretty sure that the valves that Nick sent with the heads back this latest time are still stock length. Either way... that could be it, but Im gonna trust that Jayson and Jeff had someone check it....
\chris
\chris
02-12-2002, 11:18 AM
#17
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI Hey all,
After a huge amount of wideband tuning, we have concluded that the computer is doing a great job by itself.
<img src="gr_sad.gif" border="0">
I asked Jayson to put in a set of 30lb injectors, and a new fuel filter and change LS1Tech to reflect the changes.
My thought was this: We may be looking at banging on 407 hp as the absolute limit as a CORRECTED hp, but the uncorrected numbers are really high, ie 435-440 hp. Its the *uncorrected* numbers that are indicative of how much fuel the car is using. Therefor, it probably shouldnt surprise anyone that the stock 99 injectors run out of steam at 435-440 rwhp. I had him stick in a new fuel filter since bad gas went through the car. Besides, MTI can tune for 30lbers in a few seconds and I'll have 30lb injector fuel room from then on. I suspect a good fuel pump would be necessary before any big n2o would be used though. FOr the record, Jayson doesnt think it will work, but we have run out of ideas.
Anyways...wish me luck. The saga continues...
\chris
After a huge amount of wideband tuning, we have concluded that the computer is doing a great job by itself.
<img src="gr_sad.gif" border="0">
I asked Jayson to put in a set of 30lb injectors, and a new fuel filter and change LS1Tech to reflect the changes.
My thought was this: We may be looking at banging on 407 hp as the absolute limit as a CORRECTED hp, but the uncorrected numbers are really high, ie 435-440 hp. Its the *uncorrected* numbers that are indicative of how much fuel the car is using. Therefor, it probably shouldnt surprise anyone that the stock 99 injectors run out of steam at 435-440 rwhp. I had him stick in a new fuel filter since bad gas went through the car. Besides, MTI can tune for 30lbers in a few seconds and I'll have 30lb injector fuel room from then on. I suspect a good fuel pump would be necessary before any big n2o would be used though. FOr the record, Jayson doesnt think it will work, but we have run out of ideas.
Anyways...wish me luck. The saga continues...
\chris
02-12-2002, 11:49 AM
#18
TECH Fanatic
Join Date: Nov 2001
Location: Freeland, MD
Posts: 1,347
Likes: 0
Received 0 Likes
on
0 Posts
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI Good luck Chris - sounds like there is still a mystery going on here.
Keep us posted.
Keep us posted.
02-12-2002, 11:31 PM
#19
D(irecto)r Pepper
Join Date: Nov 2001
Location: Houston Raceway Park...in TEXAS.
Posts: 1,952
Likes: 0
Received 0 Likes
on
0 Posts
Re: Interesting Grott-Y pipe and Mufflex Dyno information from my car at MTI Excellent step by step post.
Thank you.
Please keep us up to date on the changes and results.
FWIW, I "only" dynoed 383 rwhp at MTI.
I dont really give a rats *** what the dyno says...well as far as using it as an indicator of what the car will do at the track.
E.T. and MPH are the final arbitrators of how well your combo is working.
Man, take that bad boy to the track and see what it will do!
BTW, I went to 30 pounders too. I originaly did it for the extra timing.... but now that the motor is "gettin' it" I am glad I made the swap.
That LS1-edit makes tuning for the 30 pounders ... a non issue. With one click it's done. I love that thing.
I am REAL curious as to how this last round of mods affect your power out put.
Good luck
Thank you.
Please keep us up to date on the changes and results.
FWIW, I "only" dynoed 383 rwhp at MTI.
I dont really give a rats *** what the dyno says...well as far as using it as an indicator of what the car will do at the track.
E.T. and MPH are the final arbitrators of how well your combo is working.
Man, take that bad boy to the track and see what it will do!
BTW, I went to 30 pounders too. I originaly did it for the extra timing.... but now that the motor is "gettin' it" I am glad I made the swap.
That LS1-edit makes tuning for the 30 pounders ... a non issue. With one click it's done. I love that thing.
I am REAL curious as to how this last round of mods affect your power out put.
Good luck