You can get 400 flywheel hp quite easily with the LS4... Just swap the intake, camshaft, and add headers and you will be there. Max effort NA 5.3L builds can top 500 hp, so 400 hp isn't that hard. They make DoD compatible performance camshafts, so you don't need to replace the DoD lifters unless you want to, but they will likely fail sooner. My LS4 dyno'd 382 whp and should have between 420 and 430 fwhp, and still has the DoD lifters.
The real issue between the two is the transmission. While they are essentially the same, the LS4 guys break them all the time in stock form and much quicker when they add power. I suspect there is a program difference between the V6 and V8 versions (like higher tcc line pressure) that makes the V8 ones more prone to failure. If you plan to run 400 hp with the LS4 4T65e-hd, then you should also budget for a performance transmission rebuild.
As guru said, getting 400 crank HP out of an LS4 can be "easily" done with available aftermarket modifications and performance parts. I would recommend deleting the DoD system and replacing the troublesome DoD lifters with non-DoD components to avoid future potential failures.
Getting 400 crank HP out of a SUPERCHARGED 3800 (Series 2 or 3) is going to be more challenging on the engine build side since you are going to need a lot of performance parts and modifications to do it. If you remove the SC and instead install a TURBO, it is going to be EASIER to get to the 400 hp mark but will probably end up being more expensive because of the cost of a good turbo and installing it. However, once the turbo is on there, getting to 400hp and beyond becomes much easier than trying to attain the same power levels with the M90 blower.
That all having been said, it is easier and much less custom work is required to install a 3800 into a Fiero than it is swapping in an LS4. The casting for the LS4-compatible versions of this trans is unique to the LS4 and even rebuildable cores are becoming difficult to find these days. So you may want to consider this before you make your engine choice. On the other hand, 3800 Series 2 and 3 SC engines seem to grow on trees and you can use virtually ANY 4T65-E with them.
Another issue worth mentioning when it comes to very high performance builds: the casting on the 4T65-E's case is quite thin in an area behind the torque converter that is causing all the chain and sprocket problems both 3800 and LS4 guys are encountering in the very high power builds. The GM 1" racing chain was designed to "work-around" this issue, but those chains and sprockets are very scarce these days. ZZP recently released their version of the GM 1" racing chain and sprockets, but at least one guy who bought and installed one has already experienced a failure, so I question whether or not it is a viable alternative. My friend Dave over at Triple Edge Performance is testing the viability of using a basically stock 4T80-E with a high performance turbocharged 3800 in a Grand Prix to see how it holds up. Another guy did something similar in the past and had good results. Unfortunately, the larger physical size of the 4T80-E trans interferes with the block on the LS4 so the two aren't compatible. Another issue is finding a good 4T65-E that's compatible with the LS4 - the supply seems to be drying up quickly.
In any case, if you aren't shooting for anything more than 400 crank hp, you should be ok with using the 4T65-E.
As far as my personal opinion, I would rather have a 3800 Turbo than anything else. Just more potential.
Stock vs. stock an LS4 should edge out a 3800 SC performance wise, but you are going to do a lot more work to get the LS4 installed into a Fiero vs. a 3800 SC. And the money you save by doing the less amount of work installing the 3800 SC can be invested in performance upgrades that will offset that.
So really it is just going to boil down to what you want out of the swap. If you really want a V8, there's nothing wrong with choosing the LS4. But if you don't care about having a V8, the 3800 might be the better choice. They are just easier to find and install into a Fiero.
-ryan
------------------ OVERKILL IS UNDERRATED Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com
[This message has been edited by Darth Fiero (edited 06-30-2014).]
The 3800 SC will be cheaper to get, and easier to swap in. Getting 400 HP out of one should be pretty easy by swapping out the blower for an NA intake and throwing a mild turbo setup on it, and giving a tune.
The LS4 is very easy to get 400 HP out of, but it's a more difficult install, and can be more expensive to acquire the engine and trans. If you want to go manual, it's also going to be a lot more difficult. If you want auto, you'll have to make sure to get the trans that came mated to the engine, and just buy a complete drop-out. It's more work and a tighter fit into the Fiero than a 3800 will be.
Supercharged 400hp crank is pretty easy... small cam good exhaust and pulley will get you there with room to spare and a whole load more power under the curve.
Originally posted by Sourmug: Dunno, looks like it fits right at home in the engine bay:
But I'd agree that it's probably more work.
Sure, a good swap of the LS4 will definitely look good in the Fiero engine bay. But the factory water pump manifold is quite large, and interferes with the decklid hinge. The factory alternator mount for the LS4 interferes with the strut tower. Using a manual trans is a LOT more work as it only came with a very specific version of the 4t65e for the starter mount. The stock LS4 intake is pretty small and restrictive, and getting an LS6 or LS2 intake turned around on it is more fab work. And it's a physically larger engine than the 3.8, so it's a much tighter fit.
If you want cheap/easy 400 HP and you're choices are 3800 or LS4, then 3800 is the way to go.
The stock LS4 intake is pretty small and restrictive, and getting an LS6 or LS2 intake turned around on it is more fab work.
Swapping intakes and keeping DOD is what takes fab work. If you use the non-DOD valley plate (thereby eliminating DOD function), everything should bolt together, AIUI.
Swapping intakes and keeping DOD is what takes fab work. If you use the non-DOD valley plate (thereby eliminating DOD function), everything should bolt together, AIUI.
You need to use the valley plate, pull the heads and swap lifters, and pull the front cover and swap oil pumps (or at least the spring), to really drop all the DOD stuff. The non-DOD valley cover's OPSU mount interferes with the intakes as well.
There's also more fab work to relocate the hinge, or modify the water manifold to fit without modifying the hinges. Alternator mount. Starter mount if you don't get the LS4-specific 4t65e trans (ie, if you want to run a manual trans). Custom flywheel if you want to run manual trans.
LS4 cars also have separate TCM for the transmission, while I think the 3800 cars have the TCM/ECM in a single unit, so that makes for a bit more wiring and another thing to mount, if you're sticking with an automatic.
You need to use the valley plate, pull the heads and swap lifters, and pull the front cover and swap oil pumps (or at least the spring), to really drop all the DOD stuff. The non-DOD valley cover's OPSU mount interferes with the intakes as well.
There's also more fab work to relocate the hinge, or modify the water manifold to fit without modifying the hinges. Alternator mount. Starter mount if you don't get the LS4-specific 4t65e trans (ie, if you want to run a manual trans). Custom flywheel if you want to run manual trans.
LS4 cars also have separate TCM for the transmission, while I think the 3800 cars have the TCM/ECM in a single unit, so that makes for a bit more wiring and another thing to mount, if you're sticking with an automatic.
You can relocate the OPSU to the oil bypass plate and just cut and cap off the stock OPSU boss on a Non-DoD valley plate. Or drill/tap the side of the block to relocate the OPSU it as well.
All LS4's are DBW, and none of their ecms will accept a DBC solution (and the cam sensor position is unique to the LS4). I found the DBW setup to be easier than fabbing up a throttle cable bracket (and its 1 less cable in the engine bay), but most (not all) delete the DBW setup from the 3800's and use an older ECM.
The 07 and newer LS4s use the E67 ecm and you won't be able to use a stock cruise setup w/o installing the BCM and possibly other additional modules. The brake switch signal is through the CAN/BUS line and routes through the BCM and w/o it the cruise will not work.
Tuning the LS4 is also much more complicated in that it uses both Speed Density and MAF for fueling under about 4K RPM vs. the 3800's being MAF only. So you should dial in the SD table & the MAF table, but you can also set it up to run MAF only. On the 2007+ models the SD doesn't use a table, but instead uses coefficient equations. So things get even more complicated. HP tuners does not support the E67 Transmission DTC's, so if you want to turn something transmission related off, you need to use another tuning package (like TunerCat)
Yes, the LS4 swap is quite involved with all the things that have to be done to make it fit and all the additional electrical/tuning work, but as more and more are done, better solutions to the challenges should come up and help to make future LS4 swaps a little easier.
Originally posted by fieroguru: You can relocate the OPSU to the oil bypass plate and just cut and cap off the stock OPSU boss on a Non-DoD valley plate. Or drill/tap the side of the block to relocate the OPSU it as well.
Yes, the LS4 swap is quite involved with all the things that have to be done to make it fit and all the additional electrical/tuning work, but as more and more are done, better solutions to the challenges should come up and help to make future LS4 swaps a little easier.
The OPSU is easy to deal with, yeah, but it is yet another item of work that must be done if you want to use a different intake. This has to be done on other LS based engines when using Archie's kit to install, as well.
The LS4 swap (at least the full drop-out version with the auto) will get easier as more people do them, and if more people start providing kits. But I don't think it will ever be as cheap or easy as the 3800; simply due to supply and demand. The 3800 was around much longer and in many more cars with much higher sales numbers, than the LS4 was. There are a lot more options for installing a 3800, and it's a smaller and easier to fit engine. I don't think a 3800 requires any welding at all to install. I don't think we can say the same about the LS4.
Originally posted by infinitewill: I am just curios, how many Fiero LS4 swap have you completed? I know Paul has finished his, but how many have you actually done?
Why? How many have you done?
Or are you simply reading my post wrong and jumping in to try and be condescending for no good reason? Because that is exactly how your post reads.
How is the reliability of 3800 pushing 400hp..as a D/D
Assuming an engine that isn't already on its way downhill, then it should be perfectly reliable. If you're buying a used engine you basically have no idea what the internal condition is unless you take it apart and examine everything.
But it will be equally reliable making 240-260 hp or 400 hp.
Originally posted by infinitewill: Asking a simple question is condescending? Seriously? I think you are reading way to much into my question. I was just wondering how many LS4 swapped are out there? Mine was done by someone else. I know Ryan has done a few as well. I can't imagine there are more then a handful.
There are people who have responded in that way to my simply trying to provide information on the subject before, yes.
I haven't finished my swap yet, no. But I know pretty much everything I need to do to get it done, yes. I'm going the same route as fieroguru, with an F40 mated to it. So I've also been waiting to buy a flywheel from him, as he's said he would be getting a few made.
I think there are probably about 10 or so LS4 swaps running around now though. Three I know of are manual (not including my unfinished swap); fieroguru with the F40, one in Cali with the NSX trans (don't remember his name on the forum), and another in a track car (don't remember his name on here either, or which trans was used).
Mine will have full DoD delete, de-stroked to 4.8L, and hopefully making around 400 BHP. If I can ever get the time and space to get it done.
I have done several 3800SC swaps but no LS4 swaps. From what I have read on this forum; it leads me to believe that the LS4 is a far more complex and expensive swap to complete. If it were easy, we would probably have more of them. I would follow Darthfieros write up as he's completed both swaps. Just for info; member Darkhorizon has run 10's in the 1/4 mile with this engine, ZZ Performance has run in the 8's, so the potential is there to make a lot of power. IMO getting to 400HP with the 3800 may be less costly but many people prefer the V8 for looks sound and bragging rights.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I was just wondering how many LS4 swapped are out there?
Rickady88GT: 1 Darth Fiero: 2 (blkcofy & Tom Slick) Fiero King: 4 (Dogcreek and others) WCF: 2 or 3 (maybe more) Archie: 1 (Lady Lisa) Fieroaddiction: 1 or 2 (infinitewill now has one of these but Fiero King reworked it - not included in his count though)
Mwhite: 1 (F40 with aftermarket ecm) fieroguru: 1 (F40 with stock e67 ecm) Kemp3: 1 (NSX 5 speed with aftermarket ecm) Diabloroadster: 1 (auto with aftermarket ecm)
At a minimum there are 15 that have been done (running) or talked about being done on the forum, but I am sure there are others out there too. There are also a couple of other members who are close to completing theirs as well.
[This message has been edited by fieroguru (edited 07-02-2014).]
How is the reliability of 3800 pushing 400hp..as a D/D
I would suggest they are the same reliability wise. The motors are pretty strong, and the trans wouldnt really be too mad with either of them assuming you didnt try using any of the fiero transmissions.
Side note: The LS4 will make 400 but it will have a very significant lack of powerband compared to even a 375hp 3800. a 375hp 3800 will run in the 11 second range without effort behind a stock auto, while even a tweaked auto LS4 will struggle to see that at 400hp... Not saying it wouldnt see 11s though. In terms of butt dyno the LS4 might impress friends a bit more.
I decided to leave the DoD in place for now, I wasn't going for big HP numbers initially (we guesstimated between 345 - 365hp at the flywheel) but in a few years who knows? Dr. W.
If you are going to eventually ditch the DoD system, you may want to consider that doing it later, after the swap is done, will require you to remove the engine from the car, especially if you are going to change the cam.
If you are going to eventually ditch the DoD system, you may want to consider that doing it later, after the swap is done, will require you to remove the engine from the car, especially if you are going to change the cam.
That is my plan as I read your write up about DoD delete and I figured I would need to drop the engine for it. I am just rather enjoying not having to mess with anything for the time being. I figure I would do the engine and transaxle upgrade over a few winter months a bit down the road.
Dr. W.
P.S. I see I picked up 2 negs for asking a simple question? Here's an idea, grow TFU
[This message has been edited by infinitewill (edited 07-02-2014).]
That is my plan as I read your write up about DoD delete and I figured I would need to drop the engine for it. I am just rather enjoying not having to mess with anything for the time being. I figure I would do the engine and transaxle upgrade over a few winter months a bit down the road.
Dr. W.
P.S. I see I picked up 2 negs for asking a simple question? Here's an idea, grow TFU
Well I certainly didn't neg you.
But back to the topic at hand, I think Scoggin-Dickey sells a complete "kit" to disable the DoD in an LS4.
The LS2 intake, fuel rail, and throttle body fit nicely on the LS4 once you shave down and plug the oil pressure sending unit hole in the flat valley plate you'll need to get to eliminate DoD. There seems to be a million different performance camshafts available for the LS engines (which you can use in the LS4) so do your research and select the one that will fit your application best when it comes time.
Keep in mind a 2005-06 LS4 is a GEN III LS engine. And a 2007-newer LS4 engine is a GEN IV. The cam and crank triggers are different for each generation, and you need to match those to whatever computer you are going to have running your engine.
Side note: The LS4 will make 400 but it will have a very significant lack of powerband compared to even a 375hp 3800. a 375hp 3800 will run in the 11 second range without effort behind a stock auto, while even a tweaked auto LS4 will struggle to see that at 400hp...
Here is my 400+ hp LS4 dyno chart (RWHP, about 420-430 fwhp). Its a little over cammed to make up for the lift limit of the DoD lifters, but the power band is quite wide (and would be better with a better non-dod custom spec camshaft).
Please post up a 375 hp 3800 SC dyno chart so we can compare.
[This message has been edited by fieroguru (edited 07-03-2014).]
Here is my 400+ hp LS4 dyno chart (RWHP, about 420-430 fwhp). Its a little over cammed to make up for the lift limit of the DoD lifters, but the power band is quite wide (and would be better with a better non-dod custom spec camshaft).
Please post up a 375 hp 3800 SC dyno chart so we can compare.
AWESOME!
With all respect---I have NO skills remotey like yours...
Back on topic, my engine came out of an '06 GXP as did the computer, however, I am not sure about the specs on the transaxle. ...I'm not sure what the final drive ratio is but when I eventually do an upgrade I will snoop around and see what will need to be addressed with a trans upgrade as well. Dr. W.
As far as I know, all 4T65-E's that came from the factory attached to LS4 engines were all equipped with a 3.29 final drive ratio differential and 37/33 chain sprockets; which yield an overall final drive ratio of 2.93:1. Most guys opt to have the 37/33 chain sprockets replaced with 35/35 sprockets to get an overall final drive ratio of 3.29:1 to help with acceleration performance. Changing the chain sprockets inside the trans requires major transmission disassembly.
Originally posted by Justinbart: 3800 is leagues above the ls4
TROLLOL. Are you done now? This thread isn't about how much power you can make on either engine with a giant turbo strapped to it. It's about which one is a better choice for the OP at the 400 HP level.
Either engine can make 600+ HP with a big turbo and proper tune.
1.Which would be cheaper to achieve 400 hp? (That's with install and using an auto.)
2.Which would be more reliable?
Maybe i'm answering a question that you didn't ask; if so just ignore me
i have both 3800SC and v8 cars. Neither of these cars is close to 400 hp but both have more than enough power. I can offer you this:
Horsepower is like money; after you have a certain amount, going over doesn't make much difference. For me, after about 300HP you're not making a whole lot of difference in a fiero.
The difference you will feel in daily driving is the low end torque. Stock vs. stock, the 3800SC can't match the low end torque of the v8. 3800SC power comes on like a jet on take-off; the v8 is like a moon launch.
if you're looking for a lot of power and reliability on a budget, I'd suggest using an early 90's v8. The swap is well-established and it's plenty of power. Should be relatively cheap and easy, and you can always upgrade to a "modern" engine later if you want (but i can't imagine that ).
Im not a faber..and will prefer to buy swap parts as much as possiable. WIll have to learn and milk everyone for all the knowledge I can
I know nothing bout tuning..so will have to get it done.
same here, that's why both my cars are completely stock and have the OBD diagnostic ports. Also helps with licensing and smog, if necessary. Any GM mechanic should be able to work on these cars. I'd avoid mods like the plague until you have spent some time driving and living with the swap.
Im just looking for something different in my garage...I have 3 SBC swapped cars already,2 are carbed and one FI.
They are all stick shift...and I had thought about swaping one to a 4sp auto. After further research I decided to with a different eng.
I like the work done on both swaps by other members on here and decided between those 2 platforms..
As far as my HP/TK numbers: I cant see myself going through a swap and keeping a basically stock numbers The car will be pretty much DD. And no track/race time will be seen with it. When I do play with it it would be found on the interstate..
It will be a car to make me GRIN>>>and not for any practical use whatsoever
[This message has been edited by fireboss (edited 07-04-2014).]
Do you have one that starts around 2K RPM? It does show more torque than my curve, but we only get to see about 1K of the power band from start of the dyno to HP peak. My chart shows about 4500 RPM between start and HP peak.
I suspect this dyno is from an automatic with a decent torque converter stall and one from a manual would be a more direct comparison to eliminate the benefits of auto vs. manual from just the engine to engine comparison.
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