StonersTA

Hello all! Feeling a little overwhelmed but determined to get this project completed. I have a 1987 Pontiac GTA 305TPI with a T56 swap. I have a Chevrolet ZZ4 on the engine stand that I purchased a Holley Stealth Ram Intake for. I plan on spending the rest of the summer months tearing out the 305 and cleaning up/ painting the engine bay and then dropping in the ZZ4 HSR.

Current state of my Engine swap? I''m tearing out the Stock 305TPI and labeling as much as I can, since I'm not sure what I will need to reuse and what I can eliminate.

What I need from you all? HELP! I feel so overwhelmed on what I need vs. what I can ditch. Is there anyone out there that did a similar swap that can point me in a good direction? Maybe include some pictures of how you set up yours vs what you eliminated from the stock setup?

I admit I am a longtime carb guy that is now sticking his toes into the water of fuel injection, so I ask for your forgiveness now if I ask some stupid questions throughout this post!

antman89iroc

If you are planning on using the HSR then I presume you don't have emission requirements since the HSR doesn't support EGR. Also, you may wish to check on hood clearance for the firebird. My Camaro hood hits the throttle body/intake hose and had to be trimmed. I understand the bird hood has less clearance.

That being said, you can reuse your throttle body and linkage. Small things like distributor clamp and some heater hose fittings can be used. Basically take the intake and everything attached to it and set it aside to see if there's anything you need to pick off. You'll have to reroute the fuel lines etc. If you search there are a few TPI/HSR swap threads that will help you out with the intake specific details. If you are planning on ~350HP you can likely reuse your fuel injectors. The stock wiring harness can be reused just pull it back out of the way for now.

Since this is an 87 it should be MAF EFI and be more forgiving but you'll likely need to do some tuning to get the motor/intake combination really right. Look into either adding a Moates adaptor to your ecm and use TunerPro to tune or just do what I finally did and go with an EBL Flash conversion. It's really cheaper and better in the long run. There are a lot of other systems like Megasquirt but I don't have experience tuning anything but stock ecm and EBL. To change to the EBL computer it'll require some wiring pins to be moved around on the wiring harness connectors and wires added to the engine bay because you'll have to replace your MAF sensor for a MAP sensor. If wiring isn't your thing then you may be better off with the stock ecm and Moates adaptor. Tuning is a project in it's self so really check this one out. You have to be committed to tuning and it takes patience.

The rest of the motor swap is pretty straight forward. I don't know the ZZ4 specs but you'll likely reuse everything like water pump, accessory brackets, alt, AC, power steering, motor mount, exhaust and all the sensors. Since there's no emissions you can dump everything related to the AIR (smog not air conditioning) system including pump, hoses and the tubes that go into the exhaust manifolds. That step alone cleans up the engine bay. You can reroute the serpentine belt to bypass the old AIR pump or buy a delete pulley to put in it's place.

No questions are stupid. Just break the project down into sections like motor swap, intake swap, EFI tuning etc. Do a lot of searches on this site and others and make a plan. If it's too overwhelming then you may wish to enlist help or decide to stick with the TPI. It really isn't a bad intake system depending on how much power you're really trying to build. If 350-400 motor horsepower is your goal you could get there with the TPI and maybe some porting or aftermarket runner tubes. Good luck.

antman89iroc

Honestly, if I were starting over today, I would probably go with a self contained EFI single plane system like Holley and others make. I know you already have the HSR but if hood clearance is a problem and you're going to have to change out your ecm and all the other things that go along with it the Holley system is probably worth the money. Especially when you consider it's "self tuning" ability and the learning curve associated with tuning yourself. I was going for power and bit by bit change everything like my ecm, throttle body, injectors and related items. I probably spent more piecing it together than a mid level self contained system.

StonersTA

The Holley Commander 950 ECU to my understanding will replace the factory ECU. Anyone out there please correct me if I'm wrong, I havnt played with it yet to see what all it replaces and what all I will have to reuse from the factory harness and ECU.

I have already purchased the HSR and the Commander 950 so at this point shopping for a different product would be a waste of my money.

As far as hood clearance I've already decided to go with a aftermarket hood from Hawks. I love the 93-97 ram air hood they sell for 3rd gens and plan on picking that up. Its raised like a small cowl hood would be do it should have no clearance issues. Again someone out there with that hood and HSR please correct me if I'm wrong, and would love to see some pictures.

The most overwhelming part right now is more the Commander 950 and the HSR itself. Not sure what the 950 replaces, what I need to reuse. Not sure if the tuning software is user friendly. Not sure where to establish baselines? The zz4 is comparable to the 350 Tune Port motors in the corvettes I'm told. So I thought i'd throw a tune for a Stock 350 TPI car in to get started and play with it from there. I do plan on purchasing the Wideband o2 sensor that Holley sells that is a plug and play application for the 950.

Fuel pressure regulators are known to be bad with the HSR and i've read enough post on here to purchase the ones for Grand Nationals/ Typhoons. So I plan on picking one of those up soon. Right now I have the TPI 305 out and plan on cleaning up and painting the engine bay. So I have time to do some research and get parts I still need.

Welcome anyones input or pictures of their setup. Love to see what everyone did to their HSR swaps.

Thanks!

antman89iroc

Ok well the Holley commander will take care of your ecm issues. I haven't personally used it but expect it will be self tuning to a point and work well.

Changing ecm is a big project. Again, not familiar with the 950 but look at the wiring diagram for it and then one for your car. You should be able to use the factory harness under the hood to the ecm providing you mount in the stock location. It's just a matter of keeping up with each color wire at the harness/ecm connector and where it goes on the engine and connecting each one to the proper location on the ecm. Yeah there's quite a lot of wires but you'll get it. Just become familiar with the factory wiring and label it. There will likely be a fair amount of unused wires and connectors in the harness but that's good because you will probably need to repurpose them. I presume the 950 is a speed density system (MAP sensor replaces the MAF sensor) and you need to mount it and hook up the vacuum line and wire it to the ecm

As far as the Holley AFPR my first one leaked and Holley sent a replacement free of charge and the second one has been in service for around 8 years. If I replace it I would likely use an Aeromotive unit mounted on the firewall rather than the fuel rail. I have at times suspected the Holley unit of not being accurate but have no data to back that up. Yes, a GN replacement fuel regulator bolts right in. I installed one from the auto store while my Holley replacement was being sent out. I think the Kirban regulator (which is suppose to be the best one that will rail mount) was originally for the GN motors.

Hood clearance issues- solved lol.

StonersTA

The 950 has a Wideband o2 you can purchase to upgrade the system so it is more self tuning (or at least quicker). I plan on getting that in the near future.

The 950 I purchased has a wiring harness that is designed for our cars. It has a "TPI Wiring Harness" that is suppose to plug into factory sensors and what have you. Again, I havent taken it out of the box (since I'm still a few weeks away from that point of the build) so I'm not sure what all it has. Hopefully by purchasing the TPI harness for the 950 it makes this easier.

I've heard mixed reviews about the Fuel Pressure Reg from Holley. some people say they have had luck with them and others never even install them due to the horror stories on forums like this. I'm not sure if I want to risk it or just purchase the aftermarket one and only have to do this work once. I guess my wallet will decide that for me.

antman89iroc

Yeah the 900lb gorilla makes most of my decisions, lol.

efiguy

iTrader: (2)

Not self tuning at all, in fact one of the more primitive systems produced in the last 20 years. It fires all eight at once and has limited software as compared to other systems of it's era. Sorry but don't want you to think the 950 will be the second coming of Christ.
Get the wideband, don't even attempt to tune it without it. You'll be glad you spent the money I promise.

StonersTA

Thanks efiguy! I was on the border anyhow and leaning more towards buying it anyhow. I think with all the money I have wrapped up in this car now is not the time to cheap out.

antman89iroc

Thanks for clearing that up. As I said I haven't used it.

Wide band? You absolutely have to have one if you plan on getting anywhere close. And remember, a wide band isn't the second coming of Christ either, it's just one (very good) bit of information. It's output can be affected by performance cams under certain conditions but it's about the best, mobile sensors available. Also, a WB doesn't tell you what AFR is "best" in every condition so you still have to observe, evaluate and try different things to really give your engine what it wants.

StonersTA

antman89iroc & efiguy, Thanks for the input. I'm still a couple weeks to months away from getting the 950 in, but I love the input.

I also found someone on Youtube that has an hr long video on doing a HSR swap that helped quite a bit also. Unfortunately I havnt found a video of anyone using the 950.

I understand that the 950 is outdated (it came with 3.5 floppy discs lol) but I chose to go with it because it was designed to work with TPI cars and HSR specifically.

Steve Mack

iTrader: (5)

Your right Maf is more forgiving than Map alone.Thats why chevy went back to using both Maf and Map in combination on there cars.

antman89iroc

That's funny but not uncommon, especially with "legacy" hardware. When I upgraded my PC I couldn't find any with a serial port other than "industrial" types. The EBL-PC interface cable required an adaptor to go to USB. The only problem I see is getting it loaded in the first place but Holley probably has a downloadable file with the same info.

At least you are gathering info and getting your game plan together. That should make it better for you. Just be patient and realistic in your expectations. For me, I thought since it is a computer controlled EFI I should expect "14.7 AFR/128 BLM" at all times except when in PE. That has not been the case for me. At least with my cammed motor with a lot of mods. It fluctuates a lot more than I would like and it took a long time to finally come to the conclusion that perfection is an ideal not an actual goal. Maybe I'm just a crappy tuner but giving my combination a lot of tolerance has made my life less stressful and it still runs great. Someone once said (Grumpy?) to get your feet wet tuning a stock motor. I think that is good advice. It gives you an opportunity to learn what the factory accepted and an understanding of how it all works before trying to tune a modified motor. Of course I didn't actually follow that advice and had to learn the hard way.

efiguy

iTrader: (2)

I understand that the 950 is outdated (it came with 3.5 floppy discs lol) but I chose to go with it because it was designed to work with TPI cars and HSR specifically. No it wasn't.
The 950 was an extremely primitive system. Their wideband was slow and because of the total batch firing, it was very hard to tune anything with any amount of cam in it.

The engineering dept. at U.N.C.C. did a back to back test some years ago on a 300hp 350 GM crate engine. One set of tests was done with the 950, the other with a fully sequential system. Peak hp was close, but the midrange was another story. It made 25-30lbft more torque throughout on less fuel with the sequential system. That's a bunch on a 300hp application.

It is what it is I guess.

StonersTA

antman89iroc - Yea they have it downloadable off Holley's website. Nice thing about the engine i'm putting in (ZZ4) is that its close to the l98 corvette engines (as far as spec wise) so if I put a stock tune for a 350 vette tpi that would be a great starting point. So thats actually what I plan on doing.

efiguy- The ZZ4 is 355HP so everything you are saying, I am definitely listening lol!! When I say it was designed to work with the TPI cars, I just mean that it comes with a TPI wiring harness I realize that it was engineered that way. So you have given me a number of reasons why it is outdated and why you are not a huge fan of the 950, What do you recommend for my setup?

antman89iroc

I'd be interested too. Since I have only tuned the stock 165 and EBL I really don't know what a different ecm/system could do.

I recently went back to closed loop in my car. I have been running open for about a year because I just couldn't get it to do what I thought it was supposed to do. I mean it runs well except for a couple of areas but I haven't been able to keep steady 14.7 or BLMs so I went open. It runs well in open also but what I have learned is it still varies from the settings depending on a lot of conditions. When I accept that the afr is going to fluctuate and the temp and other variables have a LOT more impact on the tune than I ever really expected, it really runs well.

Sorry to jack your thread...

efiguy

iTrader: (2)

Just about anything but. And lots of main harnesses were designed to fit the TPI stuff back then, Accel, FAST, BS3 etc. That was the most popular application so it made sense.

If money is the issue, I have a used Accel or you can look elsewhere for the same or a used FAST as well etc. Something that'll run in sequential and has more tunability. You'll be glad you did.

StonersTA

efiguy, - I am so new to all this I cant help but feel overwhelmed. So If you wouldnt mind could you help me better understand the difference between the 950 I have and the Accel you have? What is different? Point of this thread is to help me better understand what I'm getting into before I get into it. You absolutely sound like you have WAY more knowledge on this topic than I do so I hope I dont come across as a pain for asking such elementary questions.

efiguy

iTrader: (2)

Been doing this since '02 but I still learn something virtually everyday.
The 950 is a much more simple system in the way of injector control and available tuning parameters. They're ok with moderately modified applications but their batch fire strategy leaves a lot to be desired. That's one reason why it was never a topline system.
Conversely the Accel was way ahead of its time for many years, offering sequential inj firing and a host of enhanced tuning options over the 950. In the right hands it's still one of the best driving systems out there today.

StonersTA

Well I haven't even started do this so please understand my feeling of being overwhelmed.

I spent $400 on a 950 from someone on here. I'm not exactly thrilled about the idea of looking for a different setup. I am listening to everything you are telling me though...

So if you were I and have already invested into the 950 would you think that the Accel is so much better that you would switch out now. Mind you I am not running anything radical here, its just a mild 350. You have mentioned on several posts that the Accel does more tuning for more radical setups. Is the 950 such a dinosaur that It will cause me more headaches? Remember all these questions are coming from someone who have NEVER tuned a ECU setup before. This is my first attempt at this whole fuel injection thing, lol.

IROCZ1989

iTrader: (1)

Efiguy sells systems. Buy one off him. If he will stand behind the sale and help with the tuning you have all your problems solved right there.

StonersTA

IROZ1989- I agree. Not sure what efiguy thinks of it all but sounds like a plan to me lol

efiguy

iTrader: (2)

Thank you very much. I'm proud of my reputation.
Yes I will help any way I can. Let me know thanks!

Mark

antman89iroc

What systems can run sequential?

I basically understand the concept, it fires the injectors in "sequence" like the firing order- correct? How does this help? (ok maybe that is too broad of a question)

For example, I run the HSR intake. Short runner front fed efi. I have heard it is prone to "cross" the ports where fuel is spit back into the plenum and goes to the wrong cylinder. Especially when the cam has a lot of overlap and at moderate loads. If that is true, would sequential firing help a situation like this? I ask because one of the strange things about my combination is cruise-low load operation at ~1800rpm. I get a surge or bucking I have not been able to tune out. 5 speed trans magnifies the problem. I can minimize it with fuel and spark but it's always there. I have been considering changing cams but it runs very well otherwise.

efiguy

iTrader: (2)

Don't change the cam quite yet, I'll bet with the right system and tune you can get most of that out of there.

StonersTA

efiguy- Like i've said in the past I am still a few weeks to months away from getting the motor back into the car. When I get to that point I would love to talk to you more about my options. Thanks for all the input and i'll be getting a hold of you soon!

IROCZ1989

iTrader: (1)

Depending on what system you get, intergrating it into the stock harness is easy. A helm book for your year helps here. If Mark will help you with the tuning process that is a big part of the equation. Instead of you say buying a system from some vendor that never has visited this website. He has made the step to actually post here to help members. Thats a big plus. Installing it is easy. Actually having someone stand behind it is another. Mark said he will so its a win win.

efiguy

iTrader: (2)

Oh no problem. Just let me know when you're ready to move forward.