Improvements vs. the Ramjet SBC/Getrag: 100 more hp 100+ lbs less (2807 total car weight vs. 2960) 7 mpg better on the interstate - 29 mpg @ 70-75 in V8 mode And the power band of a DOHC engine!
Yeah, I am pretty pleased with this swap!
382 wph @ about 6600 rpm
List of mods: 5.3L LS4 - stock heads and lower end 224/232 New Era DoD camshaft with pushrods/springs Stock LS2 intake, injectors, Throttle body Stock LS7 MAF and exhaust manifolds 4" cold air intake Magnaflow 3" in dual 2.5 out exhaust
IIRC the 4.8 and 5.3 truck LS engines that can stand up to high boost are Vortecs and are iron with beefier internals right? I think the LS4 is all aluminum?
It has been a long road to get this swap done and verified without knowing if I would be happy with it... At this point I am quite happy! It is a blast to drive. Wheel spin in 1st or 2nd is just a throttle push away, 3rd gear WOT runs are lots of fun! The flat toque curve and linear power curve is easy to control and quite predictable and 6th gear helps keep the combo fuel efficient on the interstate.
Just goes to show that GM went to a lot of trouble to choke the LS4 into obscurity. Throw the LS4 specific parts in the trash and keep the long block. Build it like any other LS based engine and then it really starts to come alive.
Now I need to get it to a drag strip to see what kind of times it is capable of. My only concern is the speed of shifting the F40. So far the F40 isn't the quickest shifting transmission I have driven, but I also haven't been forceful to it either.
Very nice!!!! Edit to add.... MM's are IMO the best looking wheels on a Fiero.
I was all set to order the New Era DOD cam for my G8 before my stupid L67 knocking. *sigh*
Thanks! I love the MM's as well, just wish I could get a matching rear wheel in 18's.
I wouldn't recommend the New Era High Lift DoD camshaft, go custom with Pat G or someone else. I degree'd it installed dot to dot and was shocked at the timing of the valve events. When I emailed them, they blew me off and told me to install it dot to dot. So then I compared the valve events with other 224 camshafts for the LS based engines and modified the timing gear to install mine to have similar events. You wouldn't believe how far I advanced it... and it still peaks at 6600 rpm.
Thanks! I love the MM's as well, just wish I could get a matching rear wheel in 18's.
I wouldn't recommend the New Era High Lift DoD camshaft, go custom with Pat G or someone else. I degree'd it installed dot to dot and was shocked at the timing of the valve events. When I emailed them, they blew me off and told me to install it dot to dot. So then I compared the valve events with other 224 camshafts for the LS based engines and modified the timing gear to install mine to have similar events. You wouldn't believe how far I advanced it... and it still peaks at 6600 rpm.
Really? How interesting. I wanted to go DOD delete untill I found out you basically have to strip the L76 down to a shortblock. Screw that! I PM'd Pat G on the G8 board but he charges a fee just to help pick a cam. Must be nice to charge for advice.
Congrats Fieroguru! Those are some really impressive stats. A great conclusion for an awesome build.
Maybe I missed it, but how have you found the clamping force and behavior of the clutch? Is it either on or off? Can you feather it easily? Does it slip at all in any torque range?
Sorry. I looked for you for about an hour between 4-5pm on Saturday, but couldn't find you and my wife was on me to meet her, the daughters, and my sister's family for dinner. I had to leave shortly after getting the car weighed. If you can make it to the LS Fest in Bowling Green in Sept, then I can take you for a spin and ride in yours as well. Sara and the girls are not planning to go with me to that show, so I will have a lot less time commitments for family stuff while at the show.
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Originally posted by Bloozberry: Maybe I missed it, but how have you found the clamping force and behavior of the clutch? Is it either on or off? Can you feather it easily? Does it slip at all in any torque range?
The clutch holds WOT w/o issue. Its rated for 500 lb-ft and my combo is probably in the 380 - 400 ft-lb at the flywheel. Drivability is very close to stock where you can slip the clutch w/o chattering at take off and it has a nice linear rate of grip until full grip is obtained. I think the clutch is key to this combo being streetable since there is little off idle torque and the 12 lb flywheel doesn't provide much inertia to get the car rolling before stalling the engine. The low 1st gear in the F40 helps as well. Had I used a clutch with more of an on-off nature, I am sure stop/go traffic would be a huge hassle to get the car to launch w/o stalling while not looking like a 16 year old driving a stick for the first time.
The only downside is I suspect the 10" clutch with its higher MOI is the cause for the perceived slowness of the shifts. The syncros have to work harder to bring down the input shaft RPM's with the larger clutch, so this might limit the 1/4 mile ET performance. However, I would rather have better drivability at the expense of 1/4 ET, especially when the nearest 1/4 mile track is 2 hrs away.
------------------ 3800 SC/IC Formula whines more than your girl... 08 Cobalt SS TC - ZZP tuned, K&N SRI, 6k HID's 13.31@107 07 HHR - Wifes (tried to have her get the SS)
IIRC the 4.8 and 5.3 truck LS engines that can stand up to high boost are Vortecs and are iron with beefier internals right? I think the LS4 is all aluminum?
No need for a turbo on that engine. That much hp is so much more than adequate. Mine is a bone stock ls4 and it handles the turbo just fine, but I have just about twice as much hp as I need. Congratulations on the build. Took a long time, but I can practically taste your satisfaction. Another well done from me. I've been totally impressed with your work right from the start.
Paul, Great video. Sorry I missed you at the 30th, but I did get to see your car. I took a few pics, I love the look. No wires, no junk, everything hidden away. I plan to take another spin at my engine bay after seeing yours. I see you mentioned the LS Fest, that is my new goal, to make it to the fest.
Having seen and heard this beast in my own driveway, I have to say it's freaken awesome! The sound of it coming down the street is fantastic. Paul, did you ever get a passenger seat in it?
Ya know that has got to be one of the best swaps going as far as power to complexity and just all around drivability. I mean looking at those curves in the dyno chart you have one quick and torquey powertrain going there. Must be a freakin' blast to drive. Sure there may be faster Fiero's here but that torque comes on quick and stays up there all the way to redline it seems. Just gobs of juicy fat torque and I can just imagine the huge cheshire grin it must put on your face when you leave the light in that little beastie. I am going with the 3800 in my car mostly due to cost and simplicity of installation but that is just a freaking lovely motor and it looks great under the hood too... You did a fine job as usual man. Peace
Pete
------------------ "May the grins begin when you turn the key and hear the engine roar over your shoulder" ......Gall57 (slightly modified LOL)
Thanks for the compliments guys! This definitely is the most fun engine swap I have done or driven (3.4pr, 3.4TDC, 3800SC, 4.3, 4.9 and a few SBC's). Its power band is most similar to the 3.4TDC, just with twice the hp, and the hp builds twice as fast.
Probably won't do much else to the car this summer except drive it and try to break it! I have a couple of other fiero related projects that will become my primary focus for the balance of the summer.
[This message has been edited by fieroguru (edited 07-09-2013).]
