LS4 / F40 swap - fieroguru (Page 30/216)
LEEEZARD JUL 28, 05:28 PM
Paul, thank you for the ls1 based 142 tooth flywheel for my lsv8/f23 conversion. your work is very nice. i gave you a plus for your craftsmanship. thank you again.
81 4.9L X-11 AUG 25, 05:01 PM
Any progress?
fieroguru AUG 25, 07:22 PM
Not on the LS4 front. Once the SBC/Getrag swap I am working on is complete, I will be hitting the LS4/F40 swap hard to get it finished.

[This message has been edited by fieroguru (edited 08-25-2011).]

Syn SEP 01, 11:08 AM
Wow, I literally just read all this information and I have to say FieroGuru you are a fountain of knowledge. You have made me change my mind about 99% about the motor and transmission I want to use in my fiero. Your documentation on this is amazing, great build, beautiful work and craftsmanship, are you going to make templates of the starter modification that you've done and the flywheel? I'm not 100% sure that with the information you've given out that people couldn't make their own templates because you've documented this so well! A+++

Syn

PS Question are you going to be retuning this to run with out Cats?

[This message has been edited by Syn (edited 09-01-2011).]

fieroguru SEP 02, 03:39 PM
Thanks for the compliments!

I have been approached by a few members about the starter bracket and the flywheel. I am not opposed to selling them once I have my swap up and running so I can validate the design. If I decide to market the F40 flywheel/clutch package, I will be able to produce them for all the common engines (60 degree, 3800SC, 4.9, N* and LS4).

As for the tune w/o cats, the lack of converters is the least of my tuning issues. With the larger MAF, LS2 throttlebody, LS2 Intake, LS2 Injectors, 224/232 camshaft and LS7 manifolds the combo will need some significant tuning to just get it to idle and drive. Once the tune is spot on, then I will be able to play with it some more to try and get the DoD feature to work with the manual transmission. Lots of tuning ahead of me.

Since I haven't posted a pic to this thread in a while, here are a few pics of my current distraction:
Syn SEP 02, 04:52 PM

quote
Originally posted by fieroguru:

Thanks for the compliments!

I have been approached by a few members about the starter bracket and the flywheel. I am not opposed to selling them once I have my swap up and running so I can validate the design. If I decide to market the F40 flywheel/clutch package, I will be able to produce them for all the common engines (60 degree, 3800SC, 4.9, N* and LS4).

As for the tune w/o cats, the lack of converters is the least of my tuning issues. With the larger MAF, LS2 throttlebody, LS2 Intake, LS2 Injectors, 224/232 camshaft and LS7 manifolds the combo will need some significant tuning to just get it to idle and drive. Once the tune is spot on, then I will be able to play with it some more to try and get the DoD feature to work with the manual transmission. Lots of tuning ahead of me.





your welcome!

and I can honestly say if you offered the starter and flywheel as a kit I would pay whatever price you wanted to charge

This is in no way a statement of any fact at all so grain of salt please, but it would seem like to me with it having DoD it would need the back pressure of the cats, I don't think that the muffler alone would give you the backpressure you would need. It just seems like that would be something that the computer would take into affect. As far as the DoD working with a manual I wouldn't think that would be that big of deal because doesn't it engage with RPM's and fuel consumption?

on an unrelated note what ever happened to that 4th gen rear glass project you had? did anything become of that?
fieroguru SEP 02, 06:57 PM
I do not think back pressure plays that big of a role in DoD performance, especially since in stock form the exhaust is immediately over sized once it enters 4cyl mode. Some long tube headers would probably help the 4cyl mode performance. I will have bigger issues with the surge/jerk that will happen when it engages/disengages and it will sound like total crap when it is in 4 cyl mode. My goal is to limit DoD activation to only happening in 6th gear, above 54 mph and below 80 mph.

DoD activation is quite sensitive to inputs from everything else. There are 27 parameters or conditions that must be met for DoD to activate and then it has time limitations for staying in 4 cyl mode and how long it must be in 8 cyl mode between 4 cyl mode events. My challenge is that 3 of the 27 parameters come directly from the 4T65e-HD that is no longer present. Transmission Gear Incorrect, Transmission Range Incorrect and Transmission gear shift in progress. Within the ECM I can limit DoD to when the selector is in drive and only in 4th gear, so I will probably setup something to show this condition when the shifter lever is placed in 6th gear on the F40. Then I can adjust the speed parameters to further limit the DoD window to where I want it.

Within the LS4 ecm program, there is also a "Manual Transmission" switch. I am curious what happens when that is selected in regards to DoD. The LS2/6 speed corvette ECM also has DoD parameters in it, so maybe GM did some initial testing with DoD and a manual transmission and deemed it to harsh during the engage/disengage events for general use. The unknown is how bad will it truly be (and one of the reasons I rubber mounted the engine/transmission).

The 4th gen hatch project is gathering dust in the basement... too many projects, not enough free time or $$$ to work on them all. Someday I might get back to it...
Syn SEP 02, 08:25 PM

quote
Originally posted by fieroguru:

I do not think back pressure plays that big of a role in DoD performance, especially since in stock form the exhaust is immediately over sized once it enters 4cyl mode. Some long tube headers would probably help the 4cyl mode performance. I will have bigger issues with the surge/jerk that will happen when it engages/disengages and it will sound like total crap when it is in 4 cyl mode. My goal is to limit DoD activation to only happening in 6th gear, above 54 mph and below 80 mph.

DoD activation is quite sensitive to inputs from everything else. There are 27 parameters or conditions that must be met for DoD to activate and then it has time limitations for staying in 4 cyl mode and how long it must be in 8 cyl mode between 4 cyl mode events. My challenge is that 3 of the 27 parameters come directly from the 4T65e-HD that is no longer present. Transmission Gear Incorrect, Transmission Range Incorrect and Transmission gear shift in progress. Within the ECM I can limit DoD to when the selector is in drive and only in 4th gear, so I will probably setup something to show this condition when the shifter lever is placed in 6th gear on the F40. Then I can adjust the speed parameters to further limit the DoD window to where I want it.

Within the LS4 ecm program, there is also a "Manual Transmission" switch. I am curious what happens when that is selected in regards to DoD. The LS2/6 speed corvette ECM also has DoD parameters in it, so maybe GM did some initial testing with DoD and a manual transmission and deemed it to harsh during the engage/disengage events for general use. The unknown is how bad will it truly be (and one of the reasons I rubber mounted the engine/transmission).

The 4th gen hatch project is gathering dust in the basement... too many projects, not enough free time or $$$ to work on them all. Someday I might get back to it...



Ok well that was about 100xs more informative than anything I've read so far on the DoD, I'm really not that big on the whole DoD thing anyways as it only yields at max 7.5% better efficiency overall. I imagine you will benefit more from DoD since you've reduced so much rotational mass. Well in any event I look forward to reading more about this and your trials and tribulations, You might make me reconsider DoD because the idea of having a 6 speed with DoD is a great idea to me because its almost like the best of both worlds but as of right now I'm leaning more toward the traditional set up.

Did you ever get anything hooked up with the 4thgen rear or was it mainly just the rear end of a Camaro set on top of a bare fiero? I love the way it looked and made my brain just go in all different directions with ideas of how I could make that work here and here with this bumper and these side panels ext ext.

Syn
fieroguru SEP 03, 08:26 AM
DoD is more of a gimmick overall, but it does work to some degree (I drove a 2009 Suburban with a 5.3 DOD from KY to DC through the mountains and averaged 19 mpg). All I am after is maximizing my interstate fuel efficiency to reduce fuel costs and fuel stops for road trips.

My big focus with it is even with the F40 the cruise RPM's will still be much higher than the low RPM's obtainable with the RWD T56 cars at interstate speeds and this higher RPM (especially on a large V8) just increases pumping losses and reduces fuel efficiency (if the F40 had a 3.0 final drive, I wouldn't mess with DoD). My smaller displacement of 5.3L will help, but the super small fiero gas tank really puts a damper on long road trips (like the HRPT when I was filling up 2-3 times a day). So I am hopeful that restricting DoD to only work at interstate speeds that it will be tolerable.

Before this swap is done, I will also have a new/larger fuel tank to maximize the available space and probably a larger expansion tank on the passenger frame rail. When I am burning up the interstate, on a long trip, I really hate stopping for gas every 2 1/2 to 3 hrs.

The furthest I got with the camaro hatch was doing the test fits and trimming the rear GT body work. Before I get back to it, I have to get a fiero with an engine in it first (my 2 88's are currently sitting engineless - the blue one is getting the LS4/F40 and an eventual chop top (hatch will not fit), the black/yellow one is getting the 4.3/F40 swap that is mostly complete and sitting on the shelf as well. The 4.3 car will be my daily driver and will probably get the hatch some day to show off this engine:


[This message has been edited by fieroguru (edited 09-03-2011).]

Syn SEP 03, 08:38 PM

quote
Originally posted by fieroguru:

DoD is more of a gimmick overall, but it does work to some degree (I drove a 2009 Suburban with a 5.3 DOD from KY to DC through the mountains and averaged 19 mpg). All I am after is maximizing my interstate fuel efficiency to reduce fuel costs and fuel stops for road trips.




That is a good looking motor! actually all your motors look good. and by they way your button head bolts on that motor look fantastic would have never thought of that. I think that if you could get enough rotational mass(which you are doing a great job of that right now) that you would actually see better fuel mileage at highway speeds, since the average is 5-7.5%. if you got 23 MPG you would get around 25 MPG. I mean that is an extra 32 miles per tank but I think your actual gas mileage numbers are going to be quite a bit better than that since its going in a car that fully dressed was about 1000 pounds lighter. but what am I telling you this for I'm sure you already know all that

So you used a GT rear for the hatch? I think I'm going to see if I can find a used rear glass (rather than take one off my Camaro lol) and do some looking, I really like the look of it and I think with the right fiberglass mods it could turn into something amazing!

Syn.