GMPP single plane..injection or carb??
6600 rpm clutch dump of death Administrator
Joined: Dec 2001
Posts: 4,983
Likes: 13
From: Texas
I'm thinking you could use the 4bl TB, and convert the car to Speed Density and use the stock computer/wiring harness/whatever.
I have been kicking this around for a buddies car who wants to convert his 79 Trans Am show car. (He wants to keep the shaker hood.) .
I hope to be testing a Speed Density tune soon.
I have been kicking this around for a buddies car who wants to convert his 79 Trans Am show car. (He wants to keep the shaker hood.) .
I hope to be testing a Speed Density tune soon.
Any motor with symmetrical ports is going to have some issue with the inside/outside ports on a single plane intake, especially on outside ports that 'turn in' towards the intake valve center on some cylinders but thats all wet flow theory even though air doesnt like to make corners either. As far as I know the EFI ford guys have problems with stock box type manifolds feeding the outer runners and the BBF 'Double E,' which this intake resembles also has problems on the outer cylinders. My guess would be the manifold was designed for a carb. Since GMPP or WAR has never released any dyno results as far as I have seen just have to take their word for it that it has excellent distribution 
I have tried a 1" and 2" open spacer + the ntrous plate and a 1" four hole spacer alone and its pretty much the same thing no matter what.
If anyone wants to flow the runners on this with my TB attached they are more then welcome, dont have a flow bench here.
Sorry for the hijak chebby - I'll make a new thread when I get the car back on the dyno..
I have tried a 1" and 2" open spacer + the ntrous plate and a 1" four hole spacer alone and its pretty much the same thing no matter what.
If anyone wants to flow the runners on this with my TB attached they are more then welcome, dont have a flow bench here.
Sorry for the hijak chebby - I'll make a new thread when I get the car back on the dyno..
Launching!
Joined: Nov 2001
Posts: 289
Likes: 0
From: Dallas, Tx
Originally Posted by J-Rod
I'm thinking you could use the 4bl TB, and convert the car to Speed Density and use the stock computer/wiring harness/whatever.
.
.
If you could adjust Ls1 Edit on-the-fly, speed density tunes would be on every corner 
Chris
Originally Posted by Cmarsh93z
Thats exactly what we have done....works perfect. With the speed density tune, you can start the race car from outside the car cold or hot, and it just purs like a kitten If you could adjust Ls1 Edit on-the-fly, speed density tunes would be on every corner
Chris
If you could adjust Ls1 Edit on-the-fly, speed density tunes would be on every corner Chris
With the SD tune will it need to be tweaked for different weather conditions?
Thanks!!!
Brad
TECH Enthusiast
Joined: Aug 2003
Posts: 596
Likes: 0
From: Downers Grove,IL
but what happens when I decide to spray a 250 shot through the plenum..
Harlan is probably doing real well because of the boost. But a NA manifold is pulsing and flow is moving around a lot inside the intake.
On my ford, distribution would get so bad with a plate at 250 jetting and a Victor Jr, I would hit 1700' EGT on 2 problem cyls while the centers were running 1300. And of course 1700+ melts holes in pistons as you very well know.
I think they have now addressed these problems on the Fords with some of the aftermarket intakes or they modify them to fix the problem. But just goes to show how crazy things can get in a single plane.
And since the Fords tend to run lean on the outside cyls not the middle, which is what yours is doing, it does seem they engineered the intake that way to run well with a carb and keep the cyls close in mixture quality.
Would be very interesting to see if you put a carb on it if the cyls evened out or not.
Steve
Thread Starter
Teching In
Joined: Sep 2004
Posts: 17
Likes: 0
Well im starting to think for n/a id stay with the LS style intakes.
Im also thinking it may be more of a problem with dpi vs carby which was one of my initial concerns with this type of setup.
Also there are some different intake ideas coming out for the GTO which will replace the stock intake and give a straight path to the t/b.
Im also thinking it may be more of a problem with dpi vs carby which was one of my initial concerns with this type of setup.
Also there are some different intake ideas coming out for the GTO which will replace the stock intake and give a straight path to the t/b.
Last edited by chebby; Dec 29, 2004 at 06:36 PM.
The NX Twin Gemini Plate that KP has on his car is made specifically for a square single plane intake. The holes in the bars spray into each runner. Makes for the best possible distribution.
Ryan
Ryan
I'm sure the plate will be OK Ryan, I will try it in small steps when the high RPM miss is gone. I hate to lean out the end cylinders if they get leaner when spraying through the intake. Being too rich with the injectors all the same and being a little lean with the N2O might make for a good balance, it obviously worked for you
I'm going to play with it more this weekend..
I'm going to play with it more this weekend..
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Brett Foote Thread Starter
Teching In
Joined: Sep 2004
Posts: 17
Likes: 0
I found this neat little TPS set-up for carburettor on one of the forum sponsors sites, it possibly could be used for running a carb on the GMPP with the stock pcm, even on A4 cars with the stock tranny..no throttle position sensor is one of the problems with going carb as you lose that input to the pcm that is needed for more than just the injection/fuel system and rigging something to work would be a time consuming PITA...so with this it may be possible to run in open loop speed density and turn the affected ses lamps off (IAC, injectors/fuelling and so on) and the rest of the car should?? 
work ok, timing, shift points etc....and hook up a logger like HP tuners to a wideband and use it to get the jetting just right at WOT 
usually a new holley runs real nice out the box if you pick the correct one and it hast been messed with 
just jet it correctly for WOT and its usually enough....i know some will think 
at the thought of a holley on your ls1 but im just going through all possible options for the intake....
TCI Remote TPS and Mount
GM type sensor mounted on base with cable actuation. Fully adjustable and works well with carburetor applications.
Description Part #
Remote TPS and Mount 377400
work ok, timing, shift points etc....and hook up a logger like HP tuners to a wideband and use it to get the jetting just right at WOT usually a new holley runs real nice out the box if you pick the correct one and it hast been messed with just jet it correctly for WOT and its usually enough....i know some will think at the thought of a holley on your ls1 but im just going through all possible options for the intake....TCI Remote TPS and Mount
GM type sensor mounted on base with cable actuation. Fully adjustable and works well with carburetor applications.
Description Part #
Remote TPS and Mount 377400
Last edited by chebby; Sep 30, 2004 at 05:46 PM.
That would probably work good for you Chebby. Or anyone wanting to run a Holley on their LS1 and keep the A4.
It would not be needed for a 350/400/PG tho. Just need a Manual transmission flash in your PCM.
Brad
It would not be needed for a 350/400/PG tho. Just need a Manual transmission flash in your PCM.
Brad
quick update, spent some time on the dyno today. Adding 7% on the center four injectors got the plugs looking pretty even. I wish I had 2+ channel EGT meter to get things a little closer but plug color has to do for now. Picked up nearly 50rwhp today after spending some time with it. We'll see what happens at the track..
Originally Posted by Ryan Karasek
Great! Guess the plug wire deal worked?
Did get it to go to 7500 a couple times and it looks like the cam peaks ~7200Most of the gains came from richening up the 4 inner cylinders and just playing with the a/f overall.
Staging Lane
Joined: Mar 2003
Posts: 86
Likes: 0
From: Houston , TX
Ok now that i see some people people running these intake , do you guys know if it is realy necesary to angle the injectors like stock intake or just put them straight ? Would it make any diference ? Thats what i'm still undecided to do on my intake . Thanx
Geomar
Geomar
my injectors are straight, Chris from APE welded injector bungs a little further upstream and on an angle for their supercharged car. With the holes drilled straight up and down in the GMPP bosses you are pretty much looking down at the intake valve if you look through the injector holes so it seems like its OK.
Staging Lane
Joined: Mar 2003
Posts: 86
Likes: 0
From: Houston , TX
Thanx man . Yeah , thats the reason I asked about it . I saw a picture of this intake with straight injectors and then i saw the one from APE at an angle . Straight would be alot more easier to do .
Thanx again
Thanx again
No problem, I dont know how far along you are with things but I may be selling my Gen7 (with pro key), rails, entire fuel system, even the already drilled intake, etc for a very nice price. I am thinking of trying out a carb setup with a crank trigger/XDI ignition to keep things a little more simple.
Shoot me a PM if interested.
Kevin
Shoot me a PM if interested.
Kevin
