Guys, I'm currently doing a 383/TPI buildup for a 1988 IROC.
I've done enough reading here to turn my brain into tapioca pudding (not that it took much to do that) and have seen that the MAF system to SD system swap is THE way to go.

To the point, is there anyone in the PA/MD/DE area that would assist me in getting the ECM/PROM work done to this project?

I have no problem purchasing whatever is required (programmer, eprom, memcal, whatever) to get it done but this DIY stuff has my head ready to explode.

I REALLY want to keep the TPI setup BUT, a good old holley sure is starting to look REAL good to me!!!

Moderators, forgive me if I have crossed any boundries here. I'm not looking for any freebies, just some experienced help.

thanks in advance, 88IROK

 

Eh, 2 days and no responses, lets see if I can contribute anything back to the community today..

I would break your project down into phases. The way I see it, here's what you got to do:

1) get educated. it sounds like you've already done that about as much as possible before step 2...

2) spend some money. Introduce craig moates (www.moates.net) and intronics to your credit card. they will send you cool stuff. pick a tuning software (tunercat, or marks software, or something) and get that too.

3) play with your new toys. burn a chip. look at the tables, use the software. just get familiar with it.

4) get a '730 ECM

5) search on this board for how to re-pin the MAF system you have to plug into the '730 ECM. I've seen it, it didn't look too hard.

6) break out the toys from step 2 (you did get a data logger, right?), hook it up to the ECM, plug in a few sensors, and see if the basics are working right - you get ALDL data, simple sensors like TPS and CTS work. (throttle position sensor, coolant temp sensor).

7) install engine, sensors, harness, etc.

8) burn a base PROM (suggest starting with the super aujp with the cylinder size and injector size set to what you actually have).

9) repeat step 6 to the best extent possible to make sure all sensors and equipment is wired correctly.

10) fire it up

11) commence tuning with all your newfound knowledge

the holley would work. but what's the fun in that? if you are willing to learn DIY tuning, and commit the little bit of cash to get all the equipment (it will cost less than a shiny new speed demon 750 anyways) and most importantly your time and learning, you can do it.

 

Like I said, the holley is starting to look REAL good !

 

I don't know what to suggest then;

half of DIY is getting over the fear and jumping in. It's like riding a bike. It's big and scary and it might rough you up a bit, but soon enough it clicks and your zooming around like everyone else.

If you're the type to slap on a holley and never change the jets or accel pump cam(s) or squirter(s) or PE valve or do any sort of tuning, well a holley is going to be easier. it will start and run and such.

if you want to make it work, you can. all the information is here. you have to jump in, buy the equipment, and start learning and doing. its no different than riding that bike or driving. you can read about it all you want and maybe some of it will make sense, but until you start riding or driving...you're missing the main show.

If you WANT the EFI, then do it. the time lost on a carb setup when what you really wanted in the first place was EFI, is time you could have spent learning EFI in the first place.

I was in a similiar situation about 2.5 years ago, I *wanted* a t56 tranny, but didn't know how to tune for it (i was in the same spot you are now) so I went for a built 700r4 with a higher stall torque converter. Then I had to learn tuning anyways (I didn't like how the stock torque converter lockup speeds affected my high stall converter) and after i got started.. long story short I have the t56 now after wasting a year and a lot of $ on the 700r4 which wasn't what i actually wanted in the first place..

If you've read enough to understand that you want to go from MAF to SD, and WHY, then it's within your grasp to comprehend this stuff, but don't expect it to be automatic. there is a learning curve for everyone, you just have to be willing to stick with it, if the end result is what you want.

 

My .02 cents: I have been running a 383 for 7 years with maf. Car has run 12.02 @ 113 and 10.97 @ 126 (with spray). Drivability is very good. Not perfect but VERY good. You may want to try the maf and see how it works for you. I have kicked around the idea of dfi and ,in my case, doesn,t seem worth the effort.

 

I agree with Floor guy, I have a 383 MAF with a mini ram III and it drives well in the city. I would like to give you track times but I haven't been with this motor! It seems like I always have the car down.....ZO6 brakes are on, just need to be plumbed now. Anyway, stay with MAF and see how it works for you! good luck.

 

I will also say that you need to reconsider "WHY" you want to dump MAF. MAF can support a lot of HP and some very fast cars are running MAF. MAF can be tuned to provide fueling when you "max out" the MAF.

There are reasons that I do consider valid for "switching to SD", such as your MAF itself takes a dump and the cost of a new MAF exceeds the cost of converting to SD (the ECM's are a dime a dozen for SD). Also, some people are changing their intakes and there isn't enough room for the MAF sensor. Those are two reasons I consider valid.

There are also some other "neat things" that you can do with SD that you cannot do with MAF (such as total ECM control of both fans if you jump a wire), but there are other ways of doing this with a MAF system too (just not through the ECM - yet).

But if you got a perfectly good working MAF system, don't be too quick to dump the MAF. Do a bit more research and see if you REALLY need to dump that MAF.

PS: I know a few SD guys that are seriously considering "retro-converting" to the 1989 MAF system.

 

I know some guys that have even gone back to carbs. <sigh>

 

Unfortunately, so do I. But, I also know a few that are now considering using an ECM to control the spark on a carb setup too.

 

Having done alot more reading on this, I'm probably going to go MAF and have PCMforLess make a chip and possibly do a tune on the car when they come up north.

What do you guys think about these cam specs:
232*/242* Dur. @ .050"
500/525 Lift
110* LSA

 

Nice cam for a 383. I don't know what your intake will be, but it would not be a good setup for a TPI (stock or LTR) setup. It will run out of breath very quickly - way before the cam starts to get into it's happy spot.

Definitely look at an aftermarket intake such as a Superram, Holley StealthRam, modified LT1 intake or Miniram (to name a few).

 

Funny thing is, Desktop Dyno gives very comparative figure for TPI vs Dual Plane w/Carb.
5400-5600 rpm peak for both.

 

Desktop Dyno falls very short when it comes to "emulating" intakes. Trust me, you don't want a TPI with the rest of the setup you are planning. I base this on ACTUAL dyno results I have seen when helping various friends with a variety of setups.

If you want to emphasis torque, then go Superram.

 

Well, there is alot to be said for the thread on siamesing the base manifold too.

 

Do as you wish. If you want to run TPI, you don't need a 383 with that cam. You may as well keep it a 355 and run a smaller cam for all the difference it will make in performance.

The TPI will CHOKE the setup you intend to build and you are just tossing money away since you will not get the full breathing potential (siamesing or not). It is similar to a guy I met that installed a ZZ4 engine with a TPIS ZZ-9X cam and TPI. The cam was a complete mismatch for the TPI. Another guy who ran a ZZ4 (with the stock ZZ4 cam and ONLY installed a Holley StealthRam) made FAR MORE POWER. That setup killed the other guys ZZ4/TPI/ZZ9X cam setup.

And a 383 will just "choke" quicker than a 350. A bone stock L98 starts to run out of breath at 4,500 rpm and you're wasting your time revving beyond 5,000 rpm. Your 383 will be an engine that runs out of breath at 4,000 rpm and fall WAY SHORT of the 224/230 cam you plan to install. Oh sure, it will rev past 4,000 rpm, but it won't make any power.

Remember the "P" in TPI is not for PERFORMANCE.

 

Have you seen the rpm ratings on the siamesing thread???
That thing was pulling good above 4500.

 

If you want TPI, consider a different cam. That dual pattern cam would be better suited to HSR/LT1/MR. All TPI variations (including the SuperRam) seem to work better with single pattern cams from what I've seen. LPE's 219/219 would be a better match than the 224/230 that your are looking at (and be easier to tune). Bigger is not always better when you talk camshafts.

FYI, I know a few guys experimenting with "reverse" dual pattern cams (with SuperRams) and obtaining promising results. These cams have less overlap, more vacuum and are performing similar to cams with a similar "intake" duration (but longer exhaust duration)...the reason is "because they need more intake than exhaust" to compensate for the reduced intake flow. Unfortunatley, these are ALL custom and very expensive. But there are a lot of "single pattern" cams available at reasonable prices.

People will say "match the cam to the heads", but you also need to consider the intake and exhaust systems to determine the "total flow" potential & ratio. Frankly, it is a pity that you don't see "head flow" with different intakes and exhaust systems to see "the real flow" the head/intake/exhaust combo will yield - and then "match the cam".

 

This cam is actually a new grind by Lunati that has been set up specifically for injected SB's.
I certainly am not trying to dismiss your opinion in any way but, engine specs have been detailed to Lunati as well as multiple engine builders to a level that most people never even realize exists.
My personal feelings are that if the TPI just doesn't seem to get it done, a 770 Demon and Dart dual plane air gap intake most certainly WILL !
I am willing to give the siamesed edlebrock base, SLP SS runners, siamesed plenum and 52mm TB a fair chance.

 

Just sharing what I and various buddies have seen & done. And what worked well, and what didn't. After you do "the siamese thing" and if you feel "not enough power", don't just scrap it all and "go carb" because you really haven't given EFI a fair chance. Consider a different intake like an HSR.

FYI, I don't have an HSR but I helped tune a number of cars with the HSR and I was very impressed with it (both performance and price wise). If I had to do it all over again, I would put the HSR pretty close to the top of "intake choices".

 

That would be me, although I started with TBI instead of TPI. This was years ago, before I even knew of the possibility of actually modding the ECM's code.


That would also be me....I figure it'll be a nice little project to keep me busy 'till I get the StealthRam. The idea is to mount a '7727 on the firewall and run $8D or maybe $58 code (since the car will eventually get a turbo or two.)


And to stay on topic: I thoroughly agree that stock-ish TPI will not come close to supporting that cam. Just because Lunati says it's for EFI SBC's doesn't mean it's right for your motor. An LT1 is an EFI SBC. Anesthes' port-injected carb intake is an EFI SBC. So was the TBI 305 that came in my RS. They all have different intakes, which require different cam profiles. With the right intake, it'll make mad power. With TPI (even upgraded and hogged out) it'll only make decent power.

My

 

Here's what I have so far guys.
I'm not real interested in spending the money they want for an HSR type setup, the carb route is way more cost effective IMHO.

1988 350 Roller Block, .030" Over.
Eagle Billet Splayed 4 Bolt Main Caps.
ARP Main Cap Studs.
Eagle 5140 3.750" Stroker Crankshaft.
Eagle 4340 6.000" I-Beam Connecting Rods.
Clevite H-Series Bearings
Mellings HV55 Oil Pump.
ARP Hardened Oil Pump Shaft.
SRP Forged 16cc Dish Pistons, 10.078:1 Static, 8.519:1 Dynamic, .015" Deck Clearance with Felpro 1094, .015" Gasket.
Plasma Molly File Fit Rings.
Lunati Hydraulic Roller Cam, Duration: 232/242 Lift: .500"/.525" LSA 110*.
Intake 10* Before/42* After, Exhaust 55* Before/7* After, 106* Center Line.
GM Hydraulic Roller Lifters.
Comp Cams Chromemoly Hardened Pushrods.
Comp Cams Pro Magnum Chromemoly 1.5 Roller Rockers.
Lunati 1.450" Dual Valve Springs 125#/330#.
Lunati Chromemoly 7* Spring Retainers.
Lunati Chromemoly 7* Locks.
Dart 200cc Iron Heads, 64cc Chambers, 2.02"/1.60", Gasket Match Porting.
ARP Head Bolts.
ARP Cam Retainer Bolts.
Cloyes True Roller Timing Set (degreed straight up).
Moroso 6Qt. #20182 Oil Pan.
Moroso #23020 Louvered Windage Tray.
Edlebrock Base Manifold, Siamesed 2.500" & Port Matched To The Heads.
SLP Semi-Siamesed Runners, Ported to 1.750".
GM Plenum, Siamesed At Runners & TB End.
52mm TB With TPIS Airfoil, Coolant Bypassed.
Home Brew AFPR.
Mr. Gasket 1.750" TPI Gasket Set.
Stainless Steel Allen Head TPI Bolt Kit.
30# Motorsports Injectors.
Edlebrock Shorty Headers (no a.i.r.).
3" Exhaust With Performance Cat & Flowmaster Muffler.
MSD 6AL Ignition System.
MSD Two-Step Module w/ Adjustable Dial Module.
5000-6000 Shift Limit, 6500 Over Rev Limit.
Moroso Lifter Valley Vent Tubes.
Pro + SFI 8" Harmonic Damper.
Scat 153 Tooth SFI Flexplate.
Custom Prom By Alvin @ PCMForLess.

Any thought on what kind of power this thing will make TPI vs Carb???

 

Please, Please listen to these guys, they aren't just some tech geeks dismissing any and all popular believes. They know because they have done it. You will have a nice mismatched combo if you keep the tpi setup. Go with a much smaller cam and you'll have a good truck motor.

Judging by your willingness to go carb, I'm going to say your going to yank the injection about 1-2 weeks after you get the motor up and running. If your going to rely on someone else to tune your FI setup, then again go with the carb becuase your going to get frustrated with the "stupid" FI setup because you can't do anything with it.

Two paths lay ahead

1. Learn how to tune FI then get a mini ram / HSR

2. Sell the FI stuff now while it's new, get carb setup.

 

Do you guys know if the in-tank fuel pump is adequate to feed a carb with the correct bypass type regulator?
I have a 255lph pump I was going to use for the TPI setup.

What some of you folks have and, are doing with DIY prom burning is indeed impressive BUT, I really don't want to spend hours and hours messing with it.
Alvin @ PCMforLess was going to do the tuning on a local dyno but again, more time, money and hassle IMHO.
All I wish to do is get it together and DRIVE!

I have seen some impressive results with the TPI setup and had planned on doing it. I'm not into this for the time tinkering with the ECM, I'm into it for the foot-to-the-floor, planted-in-the-seat, RUSH!!!

Guess I sorta answered my own question. Screw it.........hello, Barry Grant?

 

My feelings are that FI is for the guys who get the same rush from being able to have complete control over their engines, and love the fact that the reason why their engines run the way they do is because they made it run that way. At least thats why I'm doing it.

Have fun with the carb, the 255 walbro will work fine, I have a buddy who is running the stock TBI pump with a bypass reg and has no problems feeding his 350 hp motor, so the walbro will be safe insurance. Pumps flow more volume at lower pressure, so the 255 may not be necesarry but well worth the effort to throw it in the tank.

 

Thanks for the pump info.
Agreed that the injection/ecm route takes time & effort with resulting satisfaction.
As building any motor realistically requires MUCH more than just tossing some parts together, a big difference between assembling a motor and really making a motor run efficiently and perform well.

I'm an old head with a VERY in depth background making serious HP with carbs but this EFI though very familiar to you folks is like egyptian hyrogliphics to me.

I said it before, I'm not looking to conquer the EFI learning curve, I just wanna go stomp some Five Ohhs!!!

 

www.hypertech.com

 

The real problem here is the ability to tune any setup. Wanna use a holley ? go ahead. Hope you know how to tune it.

What pistons are you using? I didn't think SRP made a -16cc reverse dome for a 3.75 crank and 6.0 rod.

-- Joe

 

SRP in fact does make them (PN 138103 if you'd like to look them up)

With 12 years of building and tuning winning off-shore race boats, I think I have a real good handle on tuning a holley.

40 foot kevlar hulls + 140mph + 6 foot seas = some DAMN SERIOUS mind blowing fun!!!

Just because someone isn't experienced with burning proms, don't assume they know nothing about HP engines.

 

I think you misunderstood. I think he was "generally " saying that tuning a holley can be more time consuming than tuning the "jets" on your laptop. Tuning the chip is just like tuning a carb/mech dist. There is,
adjustable vacuum canister(Main Spark Table)
weights, springs/ mechanical advance (PE Timing table/adder)
base timing at the distributor (same procedure with a timing light and make sure the tab matches whats in the chip)
acellerator pump( AE tables)
idle screw( inside the chip based on coolant temp)
idle and part throttle fuel circuts and jetting ( ve table(s) )
wot fueling/jets etc. ( PE fuel tables)

That is a very general idea. Instead of doing all the mechanical tuning, just point and click on a laptop. It's not that hard. You just need to buy the stuff and play with it. A stock chip is somewhat safe for a base to tune, kind of like an "out of the box" carb. If you are not sure what to change then post it here or PM me. So you going to buy the equipment?

 

As a matter of fact, I already did buy the equipment.

1)Dart "Kool Can" manifold.
2)Barry Grant 750 Demon.
3)MSD non-comp Billet HEI.
4)Barry Grant Bypass Regulator.

The TPI (SLP & Edl) stuff is all on ebay as we speak.

I'm not trying to tussle with anesthes, just pinting out that to some of us old heads tuning a carbed motor is piece of cake material.
I decided that I didn't want to have to spend days or weeks messing with a TPI & prom when I can have the carb setup at 90% or better in 1-2 days AND probably end up outperforming the TPI by quite a margin.

I guess you can't teach an old dog new tricks after all.
Now, where did i put my reading glasses!

 

Cool beans. Good luck with it. TPI sucks, and I'm glad you didn't go that route. I'd have went with a victor EFI on your setup, but thats just me personally.

Let us know how it runs at the track!


-- Joe

 

Actually you CAN teach an old dog new tricks. I turn 50 this coming year if it makes you feel good.

Though I prefer EFI, I personally think you made a wiser decision with the carb vs TPI with what you are planning. I predict you would have just been unhappy and ended up going carb anyway...so why delay the inevitable? .

There is a lot of knowledgeable guys on this board and we would have helped you had you chosen EFI. But, the "good intakes" do cost money with EFI, no argument there. When it comes to "bang for the buck", it's tough to beat a well tuned carb

 

As a FWIW on TPI...


If you get the cam to play ball with the TPI induction you can make some SERIOUS power...not as much top end peak HP, but some serious low / mid range torque...this is what makes driving a car on the street FUN.

Just finished buttoning up a guy's 408 SBC in a 3rd gen Camaro.

Mild hydraulic cam, home ported / simamesed TPI base, used aftermarket large tube runners, used bigger TB, stock plenum hogged out, swap meet headers...get the idea? He has 4 kids, 1 in college, a mortgage, and 1 more going in college soon...so his "toy" money needs to be stretched.....


3.23 gears, 700 tranny w/ a Trans Go shift kit, and a used higher stall converter....

Stock 350 TPI chip.


13.40's all day long with massive traction issues.

With air bags in the back, a borrowed set of drag radials it went 13.15

He just found a guy he works with who tunes LT1 and LS1 stuff and he's been working on tuning this....

He said he's definitely got more tuning to go, but it's shown improvement already w/ a quick strip visit ( only a few passes ) it managed a 12.90......


FWIW

 

I have a 383/MAF TPI setup on my 87 Iroc with a superam. I learnd from the guys here how to program chips. My best time so far is 12.3 at 110 mph.
Keep the TPI is more impressive to go fast with a set considered to be slow.