403 LS2 FD - LS7 Build for 2020!

[drewr4411]

Nice build, definitely a good read.

[MPbdy]

Nice build, definitely a good read.

Thank you!  Pretty wild going back to receipts and old posts in my thread to find out wtf I did back then.  5+ years ago since it has been running...build started over 10 years ago now. 

I dig it that there's still some of us poking around this place. 

Awesome rings, I wonder how they compare durability wise with the reduced material.  I am at 430 rwtq, I also want to build a 427.  Nice garage!

They're definitely getting real thin!  I think down to ~ .033" at the groove.

The garage is tight but I'm loving it.  I'm finding stuff to do on the car just because I can.

[MPbdy]

So while my car is down with a leaking cooling system (god that is a familiar statement...) I found some other stuff to occupy myself with.

I've always hated my intake tube.  It was always supposed to be temporary to run the smaller GTO screened MAF until I figured out the larger LS7 MAF.  It has always looked janky, and I've been pretty convinced that the multiple sections are steering the air in the tube and causing turbulence in front of the MAF.  Last time I threw it on I really just said F-it, this garbage is going on until I get a Holley...and that is still kind of the plan, but...in the spirit of social distancing and isolation I'm finding stupid little side jobs to do.

In defense of this monstrosity, it started out as a really clean and nice looking solution that just got smashed into place to make the hood close, and after numerous times taking it on and off it really just looks like mashed asshole at this point.





Oh, and maybe I should clean my filter 



So holley has this new bitchin throttle body spacer that is cut on an 18* angle.  I was super excited to unbox this thing and try it out, but it runs into literally everything.  The TB is touching the water pump, the samberg expansion tank is in the way, and worst off the DBW plug for my throttle body is directly into the belt tensioner.

I'm working through all the little issues, and currently building a move-out bracket for the tensioner to give me more space to the DBW connector.  Overall I'm really happy with what it does for the intake tract, and I'm hoping it'll improve the tuneability of the engine and maybe even give it a little more plenum volume.  Mostly I've just hated the cobbled together look of it.  Doesn't match the effort that went into the rest of it. 

Tuning wise, even with my baby cam I've always had chugging and misfires in the parking lot and also some speeds on the freeway.  Anything with low airflows just gives the MAF crap data and you can't really tune it out.  Doesn't bother me much..but it should be glass smooth.  My excuse of poor MAF data will be harder to use when I clean up the intake tract.

The LS3/LS7 maf was atrocious in this regard.  It had continuous misfire on the freeway to the point where it was cutting in and out.  Put load on the engine and it smoothed right out. 

Even more annoying, I could never force my E40 ecu to do speed density properly.  I nailed it down to a lack of functional transient fueling in the SD mode, or at least the ability to adjust it.  The parameters are completely unresponsive, and they're pre-populated for LS2 intake, 6 liters and small heads.  I have an LS3 intake, 6.6 liters, and larger heads and it just isn't enough to keep it from bogging when you stab the gas or bang gears.

Whatever - Holley with the ls7 is a certainty.  If this isolation thing continues too long I may just got for it now.

You can see I munched off some pieces of the short side radius on the filter as well.  That used to extend up into the elbow and would definitely steer the air in the wrong direction.



Showing the interference here



The move-out bracket will put the tensioner somewhere around here.



Overall I really think it is going to be worth it.  I ordered a 4" silicone couper that will join the MAF to the TB and I'll be good to go.

[MPbdy]

A couple other things going on, my buddy with the M3 I went up ACH with is currently printing me out a prototype expansion tank.  After I limped home I took some measurements for him, and we're going to mount this thing back by the firewall on the passenger side.  I took the ABS out ages ago, so I have plenty of room and 5 or so m6 screw locations.  Once we test fit this, and design some mounting brackets for it, he'll make it for me out of stainless.  I've wanted to do this for yearsssss as I've continuously fought to keep water in this thing.  This tank will hold three times more fluid than the Howe expansion tank, and also potentially make room on the cylinder head for more fun stuff in the future. 



Also, just because, I ordered some 11/32, .120" wall thickness pushrods that are .025" longer than what I have in the engine currently.  I already have fairly long pushrods, but they're 5/16 .080 wall.  My engine has always shown a fairly quick drop-off in power above 6000.  I installed when the engine was new basic LS7 lifters that were brand new, but still would not be my first choice today.  I really wish I had some slow leakdown reduced travel Johnson lifters in there.



Anyways, the longer and stiffer pushrods I'm throwing everything I can at it that is easily accessible to hopefully extend the powerband upstairs.  My buddy suggested I try longer pushrods, and while I can't really see the length being an issue - maybe the stiffness is.  I have a moderate pressure dual spring on there right now and maybe it is just going haywire on me.

Got everything taken off in preparation.  No broken springs, and everything looked healthy inside as far as the eye could see.  Ready to slap this thing back together in between working on that tensioner bracket and the new coolant tank.

[wickedrx7]

Looking good. I love the little upgrades, it’s amazing how happy these little things can make you.

One question, why not flip the ls3 throttle body. Eliminates need for the spacer and clears almost everything. I think i only had to take a little material off the top of the water pump.

[Exidous]

I ran a TSP MAF housing with a screen that I added and a LS3 card MAF. Got the tune dead on and never had an issue with a very similar intake setup to yours. With a GM ECU. Went full SD with the MS3.

The Johnson may add a few HP but the LS7 lifters have a HUGE range for preload. I have the SLR and have a window of about .008-.010" on the preload. The rocker wipe and pushrod lengths need to be dead on. Biggest benefit to the LS7 heads is you can run a 3/8-.080" pushrod which are quite a bit cheaper than the 11/32" tapered rods I had on the LS1 with Mamo heads.

That being said, I had rather aggressive lobes and the motor carried all the way to 7k with no roll over through a fast long runner intake. Valves were extremely stable.

New setup is cammotion cam(soft lobes), SLR lifters, 3/8 rods, YT UL 1.8, TI intake and new stock late model hollow exhaust valves. Int and exh weigh about 74g each. PAC 380lb open duals. Should rev all day long until the intake chokes it.

[kinger]

If you get the MAF figured out let me know.  I want to tune with my LS7 MAF again but its just too short of a intake path to make it reliable.  I went SD and its worked great I just would love to see the actual amount of air my engine is taking in for some other aspects of monitoring/optimizing.  Glad to see updates on this one!!

[freeskier7791]

Looking good. I love the little upgrades, it’s amazing how happy these little things can make you.

One question, why not flip the ls3 throttle body. Eliminates need for the spacer and clears almost everything. I think i only had to take a little material off the top of the water pump.

Looks like he is still running a pump mounted power steering reservoir, wouldn't that need to be relocated?

[wickedrx7]

Looking good. I love the little upgrades, it’s amazing how happy these little things can make you.

One question, why not flip the ls3 throttle body. Eliminates need for the spacer and clears almost everything. I think i only had to take a little material off the top of the water pump.

Looks like he is still running a pump mounted power steering reservoir, wouldn't that need to be relocated?

Good point. I thought other people have flipped it as well but I don’t know if they have PS. Another reason to go with the FD power steering pump. 😝

[Jakewah]

Heads up on my LS1, my tuner eliminated the MAF altogether. I threw it away and my tune is now based only on the MAP at the back of my intake manifold.

[MPbdy]

Heads up on my LS1, my tuner eliminated the MAF altogether. I threw it away and my tune is now based only on the MAP at the back of my intake manifold.

That’s what I tried very hard to accomplish, but my ecu doesn’t play well without a MAF.

[wickedrx7]

Heads up on my LS1, my tuner eliminated the MAF altogether. I threw it away and my tune is now based only on the MAP at the back of my intake manifold.

That’s what I tried very hard to accomplish, but my ecu doesn’t play well without a MAF.

The e38 originally didn’t handle SD tune as well but I believe HP tuners released an update that made it much easier and doable. Maybe check to see if anything has changed with the e40.

[MPbdy]

Heads up on my LS1, my tuner eliminated the MAF altogether. I threw it away and my tune is now based only on the MAP at the back of my intake manifold.

That’s what I tried very hard to accomplish, but my ecu doesn’t play well without a MAF.

The e38 originally didn’t handle SD tune as well but I believe HP tuners released an update that made it much easier and doable. Maybe check to see if anything has changed with the e40.

The last firmware I'm running I believe is from 2008 or so, maybe with small updates since then to enable SD and better fan control range of temperatures.  I'll see if there's something new.  At first glance it looks like there is a "V3.0" that might be newer than what I have.  Would be awesome to get SD working, although I might be on track to making the larger MAF work.

The responsiveness of speed density is just so nice.  I always had the most fun driving around in SD open loop honestly..Basically as close to carbureted as you're going to get with an EFI car.  Closed loop is obviously the only way to go long term.  I seat of the pants can feel the slight transfer delay of the MAF.  Maybe that just means my blended model isn't good enough.

I ran a TSP MAF housing with a screen that I added and a LS3 card MAF. Got the tune dead on and never had an issue with a very similar intake setup to yours. With a GM ECU. Went full SD with the MS3.

If you get the MAF figured out let me know.  I want to tune with my LS7 MAF again but its just too short of a intake path to make it reliable.  I went SD and its worked great I just would love to see the actual amount of air my engine is taking in for some other aspects of monitoring/optimizing.  Glad to see updates on this one!!

Based on Exidous recommendation I just ordered some honeycomb and another 4" LS3 maf housing to try.  I really considered the TSP one, but I couldn't find a way to order just the billet housing with the honeycomb.  Didn't want to overspend to get an extra MAF and adapter harness.  Excited to try it out!  Younger me was concerned about losing some power due to flow restriction, and out of spite of not getting SD to work I just threw the old shit back on.  The larger housing with honeycomb is still much better than the Delphi MAF I'm running right now.

There's just no way to get a good MAF signal using the Samberg rad.  The run is too short, and too many bends.  They really want to see 10" straight section before the MAF to ensure smooth flow.

Looking good. I love the little upgrades, it’s amazing how happy these little things can make you.

One question, why not flip the ls3 throttle body. Eliminates need for the spacer and clears almost everything. I think i only had to take a little material off the top of the water pump.

Looks like he is still running a pump mounted power steering reservoir, wouldn't that need to be relocated?

Good point. I thought other people have flipped it as well but I don’t know if they have PS. Another reason to go with the FD power steering pump. 😝

I do have my power steering pump in the way on that side, and my harness isn't long enough.  More importantly though, the throttle body is designed to open from the bottom for proper distribution into the manifold.  Opening it from the top actually kills power and messes with distribution.

The reason for the spacer is to angle the TB down.  It isn't for hood clearance so much as it is for the proper alignment of the TB to the Samberg intake.  The LS3 intake points the TB flange upward.  The Holley spacer angles it down 18*.

The spacer is doing a lot of good things for me right now, and I think I've gotten everything to fit.  Just need to fab up a little bracket to hold the belt tensioner in place, and grind a little off the bottom of the TB to get rid of the interference with the water pump.  It bolts on now but is touching.  Just needs a little .050" clearance.

The Johnson may add a few HP but the LS7 lifters have a HUGE range for preload. I have the SLR and have a window of about .008-.010" on the preload. The rocker wipe and pushrod lengths need to be dead on. Biggest benefit to the LS7 heads is you can run a 3/8-.080" pushrod which are quite a bit cheaper than the 11/32" tapered rods I had on the LS1 with Mamo heads.

That being said, I had rather aggressive lobes and the motor carried all the way to 7k with no roll over through a fast long runner intake. Valves were extremely stable.

New setup is cammotion cam(soft lobes), SLR lifters, 3/8 rods, YT UL 1.8, TI intake and new stock late model hollow exhaust valves. Int and exh weigh about 74g each. PAC 380lb open duals. Should rev all day long until the intake chokes it.

I got non-tapered 11/32" pushrods for a reasonable price.  Summit brand.  Look like nice parts.  A little more money than the .080 wall 5/16 I had before, but they've also got more material so that's expected.  My LS7 I'll run 3/8" or maybe even bigger.  I'll have crazy stiff springs on that thing, and about .760 intake lift.

The cammotion stuff lets you do a lot without too much spring.  They make for a good street package that's for sure.

About the LS7 lifters and their super wide range of preload - yes, that's true, but it does affect power and there are trade-offs.  I have big valve pockets, and a dual spring with hollow valves and what're supposed to be very stable lobes from Comp.  If they don't float then they won't pump up - I'm shooting to preload them near the bottom of their travel to reduce the amount of oil under the plunger.

http://www.superchevy.com/how-to/engines-drivetrain/1801-the-wrong-length-pushrod-can-cost-your-engine-power-and-performance/

[MPbdy]

So, I may not have the most current files, but I'm checking tune files from my dropbox from 5 years ago and I've already found a couple errors when I was trying to run speed density...sooooooo...maybe this one is on me lol.

I just remember losing days of time beating my head against the wall when I had far more free time than I do now.  I'd be really surprised if it was as simple as not having the dynamic airflow set properly.  Just downloaded a SD tune from the repository and the dynamic airflow is set the same way.  If the MAF is failing out at the outset, I wouldn't think it would matter.

Highlighting reasons again why I really want a Holley - tired of forcing an ECU to do something it isn't meant to.

[MPbdy]

Well that sure as shit looks a lot better! My coupler came in the mail. None of it contacts the hood anymore as best I can tell, and that’s a 4” straight coupler. The 4” straight MAF tube should work just fine. This will make a nice backup plan if I still hate the ls3 MAF.