hooahh3 Posted October 12, 2016 Share Posted October 12, 2016 So going along with my other thread, might be tearing down the L28 for a rebuild. While im in there was figuring I could do some work to pick up a few HP also. Not looking for crazy high 200 whp numbers. Just a 20-30 bump at the crank. Car runs great when she is at full (stock) power, just thinking a few extra would do it right. Might save me from a 5.3 swap witch i have planned. My question is whats the best route? This will be a daily driver and rarely see 5k+ rpm on a regular basis. Ive seen and looked all these threads on heads and headers and ECU's and such. But they all kinda spiral out into other things and never really give that good of info on what im looking for. Plus by the time im through with a few hours of searching different things my heads all confused with all the different stuff that gets brought up and said. Just a simple mild build for some extra ponies. I was thinking: L28 Flat tops & 1mm head gasket for a 9.9:1~ CR (since im gonna have it torn down anyways) Good header and new exhaust Clean up the intake with some actual hard pipe and high flow filter ( some for looks, but the rubber hose kills air flow) Do MS and probably run Coil on plug GM coils just cause i have GM vehicles and can easily get 6 coils. (plus that set up looks pretty cool) Gonna do E fans and Alt upgrade mod either way. Have parts for a Turbo build but is it really worth that if this can give me what im looking for? Figure some of the gods of the L28 could shed there wisdom, Tony D and the likes. Quote Link to comment Share on other sites More sharing options...
malibud Posted October 12, 2016 Share Posted October 12, 2016 (edited) TURBO, if you are going to do all the work ... I think you will be much happier (I have a carbed car and turbo one) Just play it safe . Edited October 12, 2016 by malibud Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 12, 2016 Share Posted October 12, 2016 (edited) Screw a turbo. A 25 shot of nitrous makes that big bottle last a long time! No build necessary. The above being said...where is your horsepower now? I have picked up from 80 hp to 147 by doing a proper stock tune up! People tend to neglect the basics and look for a magic bullet to easily give horsepower... it really goes back to basics. A 20 hp bump from 120 to 140 is a very realistic possibility on an L28 without ever going inside the engine and replacing major parts. Just get what you got adjusted properly! Edited October 12, 2016 by Tony D Quote Link to comment Share on other sites More sharing options...
Greeko Posted October 12, 2016 Share Posted October 12, 2016 cough * JZ * cough lol Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 12, 2016 Share Posted October 12, 2016 Cam/headwork, and the FI to go with it. You could hit that goal with just the cam and the MS. My question is why bother? If you're already thinking 5.3 swap, a mild bump from all that work isn't likely to cut it for you. Save your time and money and do the swap is my advice. I'm speaking as a guy who built a 2.8 with a little cam and SUs. Went bigger on the cam, then went triples. Then rebuilt it for higher compression, did a bunch of headwork, then realized I had wasted a whole lot of time and money and did a 5.3 swap. Quote Link to comment Share on other sites More sharing options...
madkaw Posted October 12, 2016 Share Posted October 12, 2016 Sounds like your tentative plan would work for your goals . Just don't go wussy on the cam. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted October 12, 2016 Share Posted October 12, 2016 I was also going to say a 25-50 shot of nitrous, that is the "best" way if we were a group to use such a phrase. If you have all the parts for a turbo, I wouldn't see why you wouldn't go for that route. Granted you are explaining relatively high compression NA build which might not jive with a future turbo build, and ultimately you are talking about a v8 engine swap. Kind of all over the place here. If an engine swap is in your future, then don't dump money into this motor, if you really feel the need you can throw on some performance headers and exhaust and hear it sing. Keep up on the maintenance, rotor/cap/spark plug/wires/injector clean/fuel filter swap and save for what you really want. Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 12, 2016 Share Posted October 12, 2016 L28 Flat tops & 1mm head gasket for a 9.9:1~ CR (since im gonna have it torn down anyways) Good header and new exhaust Clean up the intake with some actual hard pipe and high flow filter ( some for looks, but the rubber hose kills air flow) Do MS and probably run Coil on plug GM coils just cause i have GM vehicles and can easily get 6 coils. (plus that set up looks pretty cool) Gonna do E fans and Alt upgrade mod either way. Have parts for a Turbo build but is it really worth that if this can give me what im looking for? There are some threads out there, maybe even in the FAQ section. Browse there. John Coffey put a good list together, if I remember, listing mods in order of impact. Bigger exhaust was high on the list, headers was low. The stock manifolds apparently flow pretty well. Simple port work on the heads is very high on many people's list. The hard pipe and filter are probably a waste of money and effort. COP won't increase power at all. E fans...not power-related. Your list is the typical general simple blingy performance stuff that parts suppliers use to get people to buy stuff. No offense. There is a good solid experience-based list out there somewhere. I'll post it if I find it. Here's the FAQ link to get you started. Try "L-series" under Powertrain - http://forums.hybridz.org/forum/38-faqs/ Quote Link to comment Share on other sites More sharing options...
hooahh3 Posted October 13, 2016 Author Share Posted October 13, 2016 and that's what i'm looking for. that solid list that's tried and true. Most people are looking or trying for way more HP increase then me. I'm an american V8 guy, don't know these to much, other then you approach the way you add power to them completely different. lol While the NOS would be nice, i'm looking for every day usable power that's there from start up. lol would be fun to add later on just to mess with. lol Idk what my power is right now, never dynoed it. But assuming(yes i know) it was close to the stock 170 awhile back, going to 200 would be a bigimprovement. about a 20% increase isn't a bad gain. Going back to my other thread, probably need a good rebuild anyways. Powers down, mpgs suck, 1-2 quarts of oil every 200 miles. which drops my oil psi when it gets low, and i don't catch it or have time/way to fix it right away. So i was thinking while i was in there doing the rebuild, might as well do the work to get more out of it if it's gonna already be torn apart. 1 reason i mentioned pistons, re install the old 1's no real difference then putting in Flats at that point and the head gasket is gonna be need either way also. I know the head needs work and would be a big improvement, but idk of any L series shops around me that are reputable to have work it over. The E fans are just to get back some parasite loss. would go light flywheel when i'd do the 5 speed swap( who i would kill for a damn OD right now!) make 200hp crank is no good if ya loose 5-10 from drag of various things before it ever makes it to the tires After driving the car for awhile, i've noticed how fast it was/ could be with about 30hp extra and i think that may be good enough. I've done upgrades and seen what a 30hp bump can really do. With suspension work and few fiberglass parts to drop some extra weight it'd be pretty bad just as is. V8 may be cheaper initially but after i start doing work to that ( cause we never stop!) and breaking all the stuff that comes with those power levels it will coast alt mode in the end. lol Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 13, 2016 Share Posted October 13, 2016 You got a lot of misconceptions and myths floating around in there... Quote Link to comment Share on other sites More sharing options...
hooahh3 Posted October 13, 2016 Author Share Posted October 13, 2016 such as? what's screwed up? Quote Link to comment Share on other sites More sharing options...
turbogrill Posted October 17, 2016 Share Posted October 17, 2016 No real experience only googling but I think what you are missing on your list is a hotter cam. Maybe only do MS fuel, that should be easy. Doing timing is a little more complicated since you need to add some position sensor. Again, haven't done any of this just research for my own build. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted October 17, 2016 Share Posted October 17, 2016 You have some misconceptions. Clutch fan isn't really a source of parasitic loss it would be things that put a load on the crank like the ac compressor and power steering. As far as I know the water pump and fan really have no real affect. Lightened flywheel also doesn't have much for parasitic loss it is more of a response dealio. Don't settle. If you are thinking V8 swap, don't settle, because you won't be satisfied and this will only delay you financially. If you think that will be enough, find a local who has similar mods and see if he/she would be willing to offer you a ride and see if it really is enough. If turbo is on your mind, flat tops will make it less happy. A turbo is basically nitrous on tap. It will get you 20-30 easy and if you wanted could push you even more. If you have all the parts and as it seems pulling and rebuilding an engine doesn't seem like a problem, I would be tempted to say work with what you have. Swaps can be fairly involved and time consuming, if you don't have enough time to fill up oil to the point where your pickup is cavitating then I would be worried you would never really have time to finish a turbo swap. You are in the ether right now, I am positive there has to be some locals with Z cars, see if you can get in touch with them. Find out what you yourself would be happy with. I know a hopped up NA L28 was a real screaming blast, but I wanted a turbo, I sold my motor for half of what I put into it before I moved on. Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 17, 2016 Share Posted October 17, 2016 . I'm an american V8 guy, don't know these to much, other then you approach the way you add power to them completely different. lol Actually, a lot of the V8 power mods are just hype also. The pushback you're getting here is because you're over-simplifying. There are lists of parts to assemble out there, some on Hybridz, some on other sites. Nobody's going to retype something that's already out there. Search "N42 flat tops compression ratio" and you'll get a ton of threads to read through. Find one that looks interesting and retype it, to discuss.. Without actually measuring power or track times, you won't know if they work or not. A loud exhaust will probably feel like 20 HP. At the end of the thread though, you'll have some parts you bolted together and it will either feel more powerful or you'll feel like you should have gone with a V8. Besides that, it's not apparent that you're actually using or really considering any of the suggestions. There's a whole long list of how the EFI system works and which parts can be modified for power n that FAQ page I suggested. does't seem like you've even glanced at it. BRAAP's opus. lol Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 17, 2016 Share Posted October 17, 2016 Here's some good reading. Most of the good discussions happened before you or I joined the forum. Many of these guys have moved on and don't post anymore. Read enough though, and you'll see who makes sense and who's just in the headers and high CR camp. http://forums.hybridz.org/topic/75978-giving-more-hp-on-a-na/ http://forums.hybridz.org/topic/56128-my-wicked-engine-rebuild-plans-are-progressing-lots-of-new-modspics/ http://forums.hybridz.org/topic/95316-braaps-l6-efi-induction-advice-and-tips/ http://forums.hybridz.org/topic/50208-the-ultimate-l28et-guidewhat-you-need-for-350whp/ Quote Link to comment Share on other sites More sharing options...
hooahh3 Posted October 17, 2016 Author Share Posted October 17, 2016 Yeah, going back to my other thread on oil consumption. Found theres also the rear main seal leaking so now it would be a complete tear down and rebuild vs what could have been just the top end. Looking through that and talking to some people about it, its looking to coast 2 grand or more for a GOOD, complete rebuild with out any of the suprises from bad parts. At this point im just gonna limp it along till ive got all my v8 stuff ready (hopefully this time next month). Time and finishing the project isn't really the issue. I will kinda be backing my self in a corner on it in a way. Fly home from work Tuesday morning like normal, start on the swap that night. Then ill have a whole 7 days of nothing but wrenching to get it done before my work week again. If I get my parts selection right and plan set up good, it should be done by then. easy to dump 100 hrs into it in 7 days. Hell I give work 95 in 7 days lol And its not really that I don't have time to add oil, it just always hits that point at the most un favorable time. Used my last quart and haven't been able to get another 1 yet. Going somewhere and its not an option for stopping or making detours, got a plane to catch. ect Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 17, 2016 Share Posted October 17, 2016 Yeah, going back to my other thread on oil consumption. Found theres also the rear main seal leaking so now it would be a complete tear down and rebuild vs what could have been just the top end The rear main seal can be changed in a few hours from underneath. It's a one-piece round seal that presses in around the crankshaft. Raise car, drop transmission, remove flywheel, change seal. Of course, while it's apart there are other things that would make sense to do. But it doesn't seem like you know how the engine parts fit together. Hard to put a plan together if you don't. Just saying, these aren't domestic V8's. A cheap way to get a clean running car back on the road might be to just find a used L6, swap it in, and drive it while you think. The engines are often in great shape even after 100,000 miles. Quote Link to comment Share on other sites More sharing options...
hooahh3 Posted October 17, 2016 Author Share Posted October 17, 2016 (edited) Did pull the valve cover and look around for just any signs of what ever, all looked good. Cleaned up, painted valve cover, polished the letters. (looks good contrasting like it does). Put it all back together and nothing, turns over but no crank. WTH!!! Smells rich, can just tell its either dumping fuel or just no spark at all. So I start going over everything, pulled out the FSM and did the MAF TPS INJ test. shot all the wires, bought new coil cause mine was reading weak on the resistance test. Checked the dizzy, points, plugs, timing. Hitting any and everything I could think of. Got it to run, and run great randomly. just put it back together as was and was thinking next move when I tried it and she ran great. Awesome, idk what was wrong, idk what fixed it but she runs again.....clean up tools and all. Close hood for test drive and nothing again. WTFFFFF!!!!! so I just left it for the night/ day it was 0630 at this point. Start again that afternoon and buddy comes over and hits the damn coolant temp sensor connector, it falls off and when I put it back on. BAM runs great. the damn connector was just loose enough to come off some times! must have hit it off and on again when I was working on it the other times. and after all night of wrenching I just missed that simple thing. Pulled up the FSM and sure enough that sensor runs into the ECU with fuel enrichment control..... . moral of the story, start with the simple stuff stupid. Don't over think yourself right off the batt. As much trouble shooting as I do at work youd think id remember that by now, but some times the brain just jumps and goes. plus being un familiar with these engines doesn't help Edited October 17, 2016 by hooahh3 Quote Link to comment Share on other sites More sharing options...
hooahh3 Posted October 17, 2016 Author Share Posted October 17, 2016 Your right, I know the basics of how they work and all obviously but as far as the exact details of these in particular im lost. never owned 1 till this one. so that's why im leaning more towards a v8 swap. Those I know and can work on easily. Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 17, 2016 Share Posted October 17, 2016 Pulled up the FSM and sure enough that sensor runs into the ECU with fuel enrichment control..... . This is incredibly old knowledge. You probably should go with the V8 swap. Go with what you know, there's a lot of new stuff to learn if you go with the L6 engine. EFI, overhead cam, the inherent weaknesses of the engine design. You'd break a lot of parts trying to work with the L6. Quote Link to comment Share on other sites More sharing options...
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