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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
After reading a ton on the forum here, I changed my 305 engine upgrade plan to include only those bolt on items I could eventually transfer to a 350 were I ever to go that route. The collective wisdom on the site convinced me not to spend a ton of $$$ on the 305. The whole plan evolved towards helping the engine breathe better but go no further than that. Dyno Don headers were installed along with this ported intake system composed of stock intake base and plenum matched to SLP runners. https://www.thirdgen.org/forums/engi...-polished.html. Comparison of stock vs. SLP runners
Stock vs. stock but ported plenum.
The cam was upgraded to a Comp Cams 12-388-4 http://www.compcams.com/Company/CC/c....aspx?csid=125 that works well with the TPI sistem. The car already had a Flowmaster muffler and the stock Cat was left in place but gutted. The EGR system was also deleted. I finally got a day off work and took the car over to Mak Performance in Hialeah to see what the rear wheel HP was. FWIW, the "seat of the pants" was WAY better than before the mods, but I was curious if this could be confirmed empirically.
Very nice car, I love it. Made more power than I expected.Leaving a lot on the table with the cam, it's barely a step up from stock. Would have loved to see a lil more aggressive grind.
Those results are abit better than the cam only longtube dual exhaust L98 i tuned. On a dynojet to boot it only did 226 whp. Stock runner. Slp’s i think would give 10-15 whp. The cam was near 218 degi think
Sometimes you get a 305 that just runs. I had a stock Lb9 that turned 14.7s and a cammed, bolt on LG4 that wouldn't do that good. One thing is for sure, TPI was engineered for 305s and this system works well on these cars.
Very nice car, I love it. Made more power than I expected.Leaving a lot on the table with the cam, it's barely a step up from stock. Would have loved to see a lil more aggressive grind.
Thanks, I was lucky to find a very low mileage car when I bought it in 2017. Been restoring/upgrading it ever since. I went with the conservative cam, cause the car's a daily driver so drivability is a priority. From my research straying too far from the stock cam would require reprogramming, right? I've spoken with several area shops and can't find anyone that can reprogram the injection system here in Miami.
The guys at Mak Performance for example do amazing work on current cars, their builds appear in magazines, https://www.racepagesdigital.com/wor...by-nitto-tire/ but they wouldn't touch the Camaro. The owner Adrian performed the run personally and called over his buds to check out the car and take pictures, LOL.
Sometimes you get a 305 that just runs. I had a stock Lb9 that turned 14.7s and a cammed, bolt on LG4 that wouldn't do that good. One thing is for sure, TPI was engineered for 305s and this system works well on these cars.
That is a fact! The TPI's ports and runners are specifically engineered for the 305. Putting the TPI on the 350 was an afterthought.
Yeah, stock auto rebuilt last year. The car's a daily driver, what would a 2800 stall speed do to drivability??
Very little for normal driving. You’ll feel alittle slip from a stop. More rpm at first from leaving at a stop but at speed it will lock up at factory programmed mph. This is where chip tuning could help but not totally necessary
but from a rolling start, going wot will feel better. Rpms will jump to 2800 ish and put motor in its power band. Much more fun
Let me know if you find anyone who tunes these things. I did a similar mod but with no cam and headers. These dyno numbers are encouraging as I had a real seat of your pants feel also when I finished. Do You know if you had the "peanut cam" in the motor? Did you rework your heads or did you leave those alone? I agree the 305 likes TPI that is why letting it "breathe" is a must if you want some real performance gains.
Post some pics of the engine bay. BTW I am in PBC so I will let you know if I find someone who at the very least can datalog the cars. I really think after all these mods a tune would just dial in all that performance.
very cool. i am heading this way myself. will also be installing edelbrock intake and still looking at heads - sounds like some really good performance gains can be had by adding those two items to this build.
Great post! Did you get it tuned? That will help a lot as well.
Thanks, I wanted to give back to TGO as this great site is a awesome repository of knowledge on these cars. Haven't gotten it tuned as I haven't found an area shop with the knowhow. If you know of anyone in South Florida please let me know! Though performance is vastly improve, I'm pretty sure it could use a tune cause mileage dropped from 13.5 mpg city to 11. OK, yes, I have a heavy foot, but still....
Originally Posted by NoEmissions84TA
Nice IROC. What did the factory claim HP & TQ to be?
Thanks, the factory specs are 190 hp and 285 ft·lb torque at the crank.
Last edited by JimInMiami; 07-14-2019 at 10:38 AM.
Let me know if you find anyone who tunes these things. I did a similar mod but with no cam and headers. These dyno numbers are encouraging as I had a real seat of your pants feel also when I finished. Do You know if you had the "peanut cam" in the motor? Did you rework your heads or did you leave those alone? I agree the 305 likes TPI that is why letting it "breathe" is a must if you want some real performance gains.
Post some pics of the engine bay. BTW I am in PBC so I will let you know if I find someone who at the very least can datalog the cars. I really think after all these mods a tune would just dial in all that performance.
Vinny, I'm can't be sure, but I think it had the stock cam before. I didn't rework the heads or do any other mods as I wanted to limit the cost and not pour a ton of money into the 305. The only other mod I didn't mention was a new air filters from Summit https://www.summitracing.com/parts/spe-hpr3915
Agreed on the need of a tune, see post above. If you're in PBC you might know Prime Tune in Pompano Beach. http://primetuneauto.com/ Paul knows a thing or two about vintage muscle and helped get the drivability back as after the mods the car initially wouldn't reliably idle with A/C on until fully warmed up. Needless to say that's a problem during Florida summers!! He doesn't however have the tools for reprogramming the ECU. Crazy coincidence, his wife has a white 3rd gen RS that he's built up to 400 hp!!
Here's the engine bay SLP runners and Dyno Don headers.
Last edited by JimInMiami; 07-14-2019 at 10:48 AM.
very cool. i am heading this way myself. will also be installing edelbrock intake and still looking at heads - sounds like some really good performance gains can be had by adding those two items to this build.
Thanks, I'm happy with the results, good luck with your build.
Very difficult finding a tuner. You almost have to learn yourself if you plan on keeping these cars with oem electronics
I'm coming to that conclusion too. I'm not allowed to work on cars in the garage of the building where I now live, so short of finding a co-op in the are and developing those skills I must rely on others. Do let me know if you know anyone in South Florida.
Last edited by JimInMiami; 07-14-2019 at 10:53 AM.
I'm coming to that conclusion too. I'm not allowed to work on cars in the garage of the building where I now live, so short of finding a co-op in the are and developing those skills I must rely on others. Do let me know if you know anyone in South Florida.
Looking good Jim
For the tune as Orr says I have downloaded tuner pro rt and got a ADX file from a member here. Purchased the proper cable from Moates and wanted to do a data log run on my own. There are members on this site that have the knowledge to burn a chip and "tunre" the car but you need the data log.info in a file from the software. My issue is I can't get Tuner Pro to connect to the car. I may need a good computer guy! I will reach out to the guy in Pompano that helped you out and maybe I can drive down there with my laptop.
My mileage went in the toilet also after my build. I think you are right where now that you got some real power you just can't help but use it!
Thats actually much better than I expected. Curious what it would run at the track
Honestly I would have expected that much or more. That setup would probably clear 260 rwhp on a Dynojet with a good tune. Mustang dyno reads about 10% lower than a Dynojet. My spare parts Vortec 305 in my 1999 Tahoe made 280 rwhp through a 4L60E and 9.5" 14 bolt on heavy P305/50R20s. Stock L30 305 long block that was re-ringed with new bearings at 250K, roller cam got removed and changed to a Lunati 218/218@ 0.050 flat tappet cam with 1.6:1 full roller rockers pirated from my Express vans 350. It got the ported upper intake from my Express vans 350, a Volant cold air intake, and long tube 1 5/8" primary headers into a dual 2 1/4" exhaust system. Swapped out the clutch fan for a set of electric fans from a 2012 Tahoe. It made 280 hp @ 5,500 rpm and just shy of 300 ft/lbs @ 3,500 at the wheels.
Honestly I would have expected that much or more. That setup would probably clear 260 rwhp on a Dynojet with a good tune. Mustang dyno reads about 10% lower than a Dynojet. My spare parts Vortec 305 in my 1999 Tahoe made 280 rwhp through a 4L60E and 9.5" 14 bolt on heavy P305/50R20s. Stock L30 305 long block that was re-ringed with new bearings at 250K, roller cam got removed and changed to a Lunati 218/218@ 0.050 flat tappet cam with 1.6:1 full roller rockers pirated from my Express vans 350. It got the ported upper intake from my Express vans 350, a Volant cold air intake, and long tube 1 5/8" primary headers into a dual 2 1/4" exhaust system. Swapped out the clutch fan for a set of electric fans from a 2012 Tahoe. It made 280 hp @ 5,500 rpm and just shy of 300 ft/lbs @ 3,500 at the wheels.
You can understand why i am hesitant to believe that when a stock motor 5.3 truck rated at 315 hp dynos 260 whp on our dyno with pcm tuning, which didnt gain much over stock tune. Much better intake heads and a smaller but still potent roller cam than your L30. Dynos are just a tool. Hard to compare. But those vortec 305 heads are decent. I just dont think a cam swap with a 218 deg flat will pick up 70-80 whp since stock L30’s are only 220 hp flywheel. Possibly underrated? Idk. Even if dyno 220 whp stock, 60 whp from a 218 cam seems optimistic
You can understand why i am hesitant to believe that when a stock motor 5.3 truck rated at 315 hp dynos 260 whp on our dyno with pcm tuning, which didnt gain much over stock tune. Much better intake heads and a smaller but still potent roller cam than your L30. Dynos are just a tool. Hard to compare. But those vortec 305 heads are decent. I just dont think a cam swap with a 218 deg flat will pick up 70-80 whp since stock L30’s are only 220 hp flywheel. Possibly underrated? Idk. Even if dyno 220 whp stock, 60 whp from a 218 cam seems optimistic
I'm not hesitant to believe it at all. I just flat out don't believe it. I'm with you on this Orr.
Looking good Jim
For the tune as Orr says I have downloaded tuner pro rt and got a ADX file from a member here. Purchased the proper cable from Moates and wanted to do a data log run on my own. There are members on this site that have the knowledge to burn a chip and "tune" the car but you need the data log.info in a file from the software. My issue is I can't get Tuner Pro to connect to the car. I may need a good computer guy! I will reach out to the guy in Pompano that helped you out and maybe I can drive down there with my laptop.
My mileage went in the toilet also after my build. I think you are right where now that you got some real power you just can't help but use it!
Burn a chip, how's that done?? Is there a gizmo where you insert a new blank computer chip and actually program it, then said chip is placed in the car's ECU?? Sorry, probably a dumb a$$ question, but tho I know how to turn a wrench, electronics have always mystified me. Paul at Prime Tune told me that back in the day he used to fool with that stuff, but no longer has the DOS based computer do do it, or at least that's what I understood?
You can understand why i am hesitant to believe that when a stock motor 5.3 truck rated at 315 hp dynos 260 whp on our dyno with pcm tuning, which didnt gain much over stock tune. Much better intake heads and a smaller but still potent roller cam than your L30. Dynos are just a tool. Hard to compare. But those vortec 305 heads are decent. I just dont think a cam swap with a 218 deg flat will pick up 70-80 whp since stock L30’s are only 220 hp flywheel. Possibly underrated? Idk. Even if dyno 220 whp stock, 60 whp from a 218 cam seems optimistic
Stock marine L30 is 260 hp and 297 tq with a 196/206 roller cam.
The L30 head 218/218 flat tappet cammed flat top piston 312 in my 1980 Corvette went 12.5 @ 112 on a 2.2s 60'. Had a victor jr and 500cfm edelbrock. Long tube headers and pypes exhaust. Powerglide with a stock converter and 3.07 rear gear. Car was a little over 3,200 lbs race weight with me in it. Do the math on what that cam and the L30 heads are capable of. The old 862/706 4.8/5.3 heads really do not flow any better than the Vortec 305 heads and flow worse than the good (not hecho en mexico) 350 Vortec heads.
OK, so I will ask, "Is there a difference between the marine engines and the car engines"?
Or is the difference due to the engines being factory dyno(ed) with all accessories installed?
A lot more accessories in a car than in a boat and boats do not have to pass emissions, to my knowledge.
Last edited by NoEmissions84TA; 07-14-2019 at 08:23 PM.
OK, so I will ask, "Is there a difference between the marine engines and the car engines?
Or is the difference due to the engines being factory dyno(ed) with all accessories installed?
A lot more accessories in a car than in a boat and boats do not have to pass emissions, to my knowledge.
Cam, Intake manifold and Exhaust manifolds are all different. The intake is less restrictive, the exhaust manifolds are larger and breathe better and the cam is the same cam as the Ramjet 350.
You can understand why i am hesitant to believe that when a stock motor 5.3 truck rated at 315 hp dynos 260 whp on our dyno with pcm tuning, which didnt gain much over stock tune. Much better intake heads and a smaller but still potent roller cam than your L30. Dynos are just a tool. Hard to compare. But those vortec 305 heads are decent. I just dont think a cam swap with a 218 deg flat will pick up 70-80 whp since stock L30’s are only 220 hp flywheel. Possibly underrated? Idk. Even if dyno 220 whp stock, 60 whp from a 218 cam seems optimistic
5.3 is probably overated from the factory. My stock 245 hp 5.7 Vortec made 210/290 on a Mustang dyno with the TB lip removed and the tuned PCM. Bone stock was 180/250 on the same dyno. With a 4L60E and 3.42 gears pulled 6,000 lbs to a 17.3 @ 80 stock and a 16.3 @ 82 with tuning.
A similar spec XE 262 cam gained close to 50 hp when tested against a LG4 cam with the stock 416 heads on it in Car Crafts 325 hp build.
That 218 cam is more like 221/221 @ 0.050 with 1.6 rockers.
The Lunati HE 268 with 1.6s.
268/268 @ .006
221/221@ .050
.487/.487 lift
110 LSA and 106 ICL
What you are not realizing as well as that is 220 hp with all the accessories including the a/c operating and turning the clutch fan. Its also breathing through the factory exhaust. Headers and a decent exhaust adds about 30 hp to a stock L30.
Cam, Intake manifold and Exhaust manifolds are all different. The intake is less restrictive, the exhaust manifolds are larger and breathe better and the cam is the same cam as the Ramjet 350.
Thanks, good to know. If I ever have to buy a SBC long or short block, I will go for the marine version.
Burn a chip, how's that done?? Is there a gizmo where you insert a new blank computer chip and actually program it, then said chip is placed in the car's ECU?? Sorry, probably a dumb a$$ question, but tho I know how to turn a wrench, electronics have always mystified me. Paul at Prime Tune told me that back in the day he used to fool with that stuff, but no longer has the DOS based computer do do it, or at least that's what I understood?
Yes, exactamundo. The ECM is under the pass dash, you drop it down. remove the cover. You remove the prom which is the blue thingy under the cover. You then install a "bar" with the new chip and then reinstall the prom to the new "bar" IDK the actual name of said "bar" You need the info on how the car is running, BLM's, AFR's and other thinks Greek to me. A guy with the gizmo cam make the proper adjustments based on the info from the ECM. You don't even have to open your hood. I will let you know what Paul says after I speak with him.
Yes, exactamundo. The ECM is under the pass dash, you drop it down. remove the cover. You remove the prom which is the blue thingy under the cover. You then install a "bar" with the new chip and then reinstall the prom to the new "bar" IDK the actual name of said "bar" You need the info on how the car is running, BLM's, AFR's and other thinks Greek to me. A guy with the gizmo cam make the proper adjustments based on the info from the ECM. You don't even have to open your hood. I will let you know what Paul says after I speak with him.
Thanks Vinny, I look fwd to hearing back. Tell Paul James with the white IROC sent ya.
It really isnt that difficult to do. There’s plenty of good reading in the DIY PROM tuning section here. The chip adapter and burner/cable setups will run you about 225$ but thats not terrible. I’d also suggest a wideband o2 setup like an aem for 170$ or so as well
It really isnt that difficult to do. There’s plenty of good reading in the DIY PROM tuning section here. The chip adapter and burner/cable setups will run you about 225$ but thats not terrible. I’d also suggest a wideband o2 setup like an aem for 170$ or so as well
You would think so Orr.I have done my homework but just not familiar with the operation of the software. Hell it took 2 weeks just to figure out that the 2 arrow tab is the initiate! and 3 weeks prior getting to that point. I need a little knowledgeable guidance from someone familiar with it, a little training so to speak.
I called Paul and next week I am going to bring my car, computer and cable to him. He says he just does not have the tools anymore to accomplish this. When I told him what I had already he agreed to help.
Jim, I will let you know how I make out. I will also look into this wideband thing you speak of.
You would think so Orr.I have done my homework but just not familiar with the operation of the software. Hell it took 2 weeks just to figure out that the 2 arrow tab is the initiate! and 3 weeks prior getting to that point. I need a little knowledgeable guidance from someone familiar with it, a little training so to speak.
I called Paul and next week I am going to bring my car, computer and cable to him. He says he just does not have the tools anymore to accomplish this. When I told him what I had already he agreed to help.
Jim, I will let you know how I make out. I will also look into this wideband thing you speak of.
You would think so Orr.I have done my homework but just not familiar with the operation of the software. Hell it took 2 weeks just to figure out that the 2 arrow tab is the initiate! and 3 weeks prior getting to that point. I need a little knowledgeable guidance from someone familiar with it, a little training so to speak.
I called Paul and next week I am going to bring my car, computer and cable to him. He says he just does not have the tools anymore to accomplish this. When I told him what I had already he agreed to help.
Jim, I will let you know how I make out. I will also look into this wideband thing you speak of.
Visit the tunepro rt website and download it. Its free although you can register it for 30$ to help the cause lol. Then get your files, you will need and xdf to read bins and adx to datalog. Alot of it can be found on tunerpros site as well or diy efis forums. Else someone can email you some. Then find a bin. You can read your code off your computer, should be a 4 letter code on the ecm or chip itself
for now just download anything and start looking at the stuff. See what it looks like
Hah, go ahead and have fun at our expense. Once we figure this (and 57 other things) out we'll leave you choking in our newbie dust!!!
Yal get it figured out Jim and Vinny. I'm gona cheer yal on from my computer desk, Ive been in these cars since 93 and haven't learned any tuning yet so I doubt I ever will at this point. Good luck with it guys, two gorgeous cars!
Yal get it figured out Jim and Vinny. I'm gona cheer yal on from my computer desk, Ive been in these cars since 93 and haven't learned any tuning yet so I doubt I ever will at this point. Good luck with it guys, two gorgeous cars!
Visit the tunepro rt website and download it. Its free although you can register it for 30$ to help the cause lol. Then get your files, you will need and xdf to read bins and adx to datalog. Alot of it can be found on tunerpros site as well or diy efis forums. Else someone can email you some. Then find a bin. You can read your code off your computer, should be a 4 letter code on the ecm or chip itself
for now just download anything and start looking at the stuff. See what it looks like
I will try the Tuner Pro site, That is one place I have not looked except for the download. I got an ADX file from Tunned Performance. One of the other things is the Dashboard feature in tuner pro. I have seen and read some tutorials but can't seem to get one set up. I am stuck on a default one that just shows the TPS sensor 10 times over, and that does no good as I have to connect 1st. I have been mechanical all my life and have had a knack for figuring stuff out that has stumped me. When it comes to software and linking computers man I feel as dumb as they come!
I say skip the whole burning chips thing. Buy a Moates Ostrich 2.0, and be able to tune on the fly. It is so much easier. Being able to make changes while driving is a huge plus.
I would also recommend a wideband to tune the Power Enrichment. Going from your narrowband readings is not accurate I have found.
07-12-2019, 08:37 PM
except for the download. I got an ADX file from Tunned Performance. One of the other things is the Dashboard feature in tuner pro. I have seen and read some tutorials but can't seem to get one set up. I am stuck on a default one that just shows the TPS sensor 10 times over, and that does no good as I have to connect 1st. I have been mechanical all my life and have had a knack for figuring stuff out that has stumped me. When it comes to software and linking computers man I feel as dumb as they come! 
