Although i do not have a 3rd gen f body, I joined this site for the wealth of tunned port injection information. I have a 1969 Camaro with a L98 and Muncie 4 speed. The car has had a Holley pro injection tbi from the 90s on it for like 10 years. The tbi performs decently under power but always runs rich at cruise, wants to flood on start up intermittently and is an archaic system only using tps and coolant temp as inputs. I want to convert to multiport, and tpi seems like the best budget way to do it. I know the limits of the factory tpi system and would possibly upgrade the intake to stealth ram or pro-ram in the future while still using the tpi harness, distributer, ecm. etc. I already have a complete set up off a 89 GTA. I think the GTA engine was a reman 350 some one installed with the OE 305 tpi on it. Some tpi parts and knowledge are getting hard to come by. I have many questions and I'm not sure if this is the right forum to post them on or should i be in a different forum?
My engine is the corvette L98 350 with aluminum heads on it and i don't think they have any port work done but were set up by a machine shop. Cam is the comp x282hr-10 .510/520 lift, 230/236 duration @.050, 110 lobe separation. Valve springs that match the cam and 1.5 inch roller rockers. It has 1 5/8 headers. I know the cam is overkill for the heads and tpi setup but it will not be getting changed. Heads are not coming off at this point either. I will port the tpi components to the best of my ability. I'm deleting the egr. I need to modify the fuel lines to exit the rear of the rails. Electric fuel pump and a 1/4" return line are already installed on vehicle. The car has no heat, A/C or cruise so it should be a relatively easy install. I tried searching for a 69 Camaro install on this site but nothing comes up, probably because its been so long since someone has done it and everyone has been going LS for so long. If anyone knows a link to a 69 Camaro install it would be really helpful.
Some questions are
1 Is it worth porting the intake if the heads aren't ported? i wouldn't port the head side of the intake
2 Does the ecm need to see vehicle speed sensor if i have a manual trans? Due to shifter location the car has no speedo
3 Is the vehicle antitheft system going to be a problem for me? I don't have the key to the car i got the tpi from so I can't do the resistor thing
4 Does the tpi distributer need a bronze gear and will the one off my hei fit it?
5 Can i run my mechanical fan at this point for ease of installation? If I can work the air intake pipes around it.
6 Can you run the 19lb injectors on a 350? I believe the car i got the tpi off was doing this.
7 This will be the MAF set-up, but should I go to speed density?
8 Where can i currently get a chip burned for my set up.

 

I'm pretty close to your setup, having swapped TPI into my '71 Camaro about 25 years ago, although like you, nothing is factory anymore.

Just right off the bat, your cam is going to be severely mismatched to the heads and intake, which seems like you're already aware of. Just be mindful of that because you could get disappointing results.

There are several parameters that need the vehicle speed, so you may get some nuissance driveability issues... though it may not be as pronounced since you have a manual. Things like the engine not wanting to idle down quickly enough when coming to a stop. But overall, you can get it to run ok.

In terms of the VATS, you're clearly going to need a custom tune. In which case, the tuner can simply disable the VATS within the calibration.

If you have a roller cam now, you should already be running a compatible distributor gear. If its flat tappet, then you don't need that. Regardless, I wouldn't run bronze on the street. A factory gear from a 87-91 Corvette or 88-92 Camaro/Firebird is the melonized version which will work nicely.

Mechanical fan is fine. The ECM doesn't know or care whether electric fans are installed.

19 lb/hr is too small IMO. You must have gotten a 305 engine. For a 350 (and particularly if you plan to do any future mods, I'd go 24 minimum.

MAF vs MAP... I'm sure there's debate about this. All I know is MAP since that's what my system is and it performs very well and I've learned to tune on that system. But it does require quite a bit of tuning on a modified engine to get it right (especially if you're a perfectionist and **** about it like me). MAF has always been understood to be more adaptable to mods, up to a point. But, no doubt you will need some tuning.

Contact Tunedperformance on this site for custom chips. Though what will make everyone's lives easier, particularly with the cam you intend to run, is to get set up with Tunerpro RT so you can take data and send back to him for review. Tuning blind is often very difficult and can lead to frustration. If he can see how the engine responds to the changes, you'll get to the end result much more quickly and efficiently. When you give him feedback on the changes, actual data will put your seat of the pants descriptions into better context. Also, a wide band O2 will likely be a must-have in this case.

But overall, my advice would be to dial down that cam into the low 220's duration @.050 (as an absolute maximum). If it were me, I'd be down into the 215-220 range with those heads and a TPI manifold. I really think you're going to have disappointing results with your current cam.

For example, on my Miniram'd 383, you'd think I'd want to run a cam closer to 230@ .050. But I'm only at 215@.050. Yet this thing is an absolute missile, but still maintains very pleasant street manners. You don't need a ton of camshaft duration to make really good power on the street... plus it'll be much easier to dial in the calibration.

 

That cam is not a good choice for a long runner intake. The TPI is done where that cam takes off, it simply cannot support the airflow. It would be a nice match for a Stealth Ram, Miniram, Pro-Flo, dual plane, single plane, anything with a medium to short runner that can flow more air at higher rpm. You should watch this:


There are gains to be had by porting the intake, as per above video.
It doesn't seem like you'd need the VSS for anything in this application but I'm not a stock ecm expert.
With the stock prom, yes it's expecting a square wave from VATS. You can defeat this with https://www.ebay.com/itm/282700412289? or simply have it turned off when the rest of the tune is modified to work for your application.
The TPI distributor from '89 is a small cap divorced coil HEI. The gear will physically fit, check with the cam manufacturer for what metal they want.
You can do whatever fits in the engine bay. You'll know if it doesn't cool enough.
You're not seriously considering used injectors on a fresh build I hope? Put 24s in it.
I would, so you aren't dependent on that specific MAF. If it were my car I'd go with an aftermarket ecm.
Tuned Performance

 

I know you're looking for tpi advice but why not use a modern standalone EFI like a Edelbrock pro flow XT. I've had one for 3 years and it's been awesome and runs great. I have a cam similar numbers to yours. It was and easy install and a million times better than the systems from the 90s. And you can swap what ever you want when ever you want w these.

just a thought.

 

Thanks for the replies. Good call on the factory distributor already having the melonized gear. It is currently a roller cam with a bronze gear on hei. I will plan on going with 24lb injectors and look into the tunner pro. The vats bypass is interesting. I didnt know they made something like that. I also watch the richard holdener videos. In his newest tpi video he dynos a 350 with x282hr cam and still makes over 450ft lbs from 3500 rpm to 4250 rpm, tq peaked at 469 and hp peaked at 375 at 5000rpm. Before that he did the xr270 with almost the same results just sooner in the rpm band. Granted they were running afr 195 heads and probably over $1000 worth of tpi intake upgrades. Impressive, but I know stock heads will not produce anywhere near this. I know the tpi will limit the engine but if had just put a carburetor on it, the cam would not be that extreme of a choice, operating rpm I is 2200-5800. I do not disagree about the advantage of a smaller cam, but I will not be changing the cam. The prices of roller cams seems to have doubled and the cost of just a few parts to get the tpi on it makes me wonder if I should just put carb on it instead. I would buy better heads before the doing the cam. The factory tpi intake will just be a stepping stone for me until I get a better flowing set up. Even if I'm disappointed in the results, this car is just a cruiser. I have other cars if i feel the need to be competitive.
ULTM8Z Did your stock throttle cable work? I know people swap the 2nd gen cable and pedal to get rid of 1st gen style.

 

The VSS input is used for DFCO, cruise fuel and spark trims, electric fan control, and a "shift" lamp on a manual trans vehicle.

If you grab a copy of Tuner Pro from Mark, you can also get the definition and binary file(s) for the stock L98 and see what is involved, what you can turn on or off, and what you can control or modify.

 

I had gotten a factory 3rd gen throttle cable but I had to shorten it a bit. It's lasted for 25 years now.

These days probably would get a Lokar or something like that.