Any TPI swappers in here?

[phishfud]

I am gonna be doing a TPI swap on my 84 hopefully in a month or two. Already have the TPI setup from an 85 Camaro, which will allow me to keep my old style heads. I have the wiring harness figured out, and where I am gonna get it. My parts truck was a dual tank TBI, so gonna use the tanks from it and install F-body TPI fuel pumps. I will be using a speed density setup, and using a dual electric fant unit from a TPI f-body. I have most everything figured out, but thought i'd see if anyone has done the swap, and what kinds of other issues you may have run into. This is going on a GM crate 350 which was rated at 260hp/330ft.lb. Nothin wild, but moves my K10 pretty good. Any advice or cautions on the swap wold be great. Thanks.

[Pyrotechnic]

I would have the injectors tested and cleaned or buy a set of new ones if this intake came from a junkyard or very old vehicle.

http://chevythunder.com/fuel%20injec....%20pg%20A.htm

There's some info on interchangeability amongst these systems.

[piecesparts]

Agree on the injectors. The Delphi design (wafer disk) units from those years were basically funky stuff and should be updated. I spent some time with Mark Campbell in Mena, Arkansas (Street and Performance) and I learned that those injectors are lousy in performance. I update with a pintle design injector and used a FORD racing unit for replacement. They are cheaper to purchase, also. I put a new set on my 95 Impala SS and they are great.

Did you get all of the mounting brackets for your accessories? The spacing for the alternator and A/C is different on those brackets over the factory TBI brackets. You need the room for the air intake and
throttle body.

The electric fans will give you a lot more room over the factory fan shroud.

You can step up that setup if you switch to a set of vortec heads and a new baseplate from Scoggin Dickey for the vortec. That along with the high flow runners would be worth about 40 horsepower.

[phishfud]

I did get a complete serp setup from a TPI car, and it is already on the truck. I have a set of stock 22lb. injectors I need to send out, but may upgrade later. I seriously considered going the Vortec route, but for now, my swap to TPI is just for reliability. Once I have it on and running, I might start upgrading the cam/intake/heads. I figure one step at a time and I'll have less headaches. Besides, I already have the Accel/Lingenfelter base on my TA(which I am pretty sure accepts Vortec heads), so the TA gets more upgrades before the truck. Truck needs paint and a bed before I start with engine mods or lifts.

[piecesparts]

Ditch the stock 22 lb injectors and look for a better unit. Also, Iwould stay away from the Accel units, they are troublesome and not worth the effort, from experiences that some of my buddies have had.

[phishfud]

I've heard all kinds of bad things about the Accel injectors. I've heard the Ford SVO ones are pretty good, though. I'll have to start shoppin around, as I know I have a bad stock one in my TA, and have been putting off fixin it.

[piecesparts]

I started pricing injectors awhile back for the 95 Impala; GM wanted a $100 a piece for them, I looked at S&P and they had FORD injectors for $399.00 for a set of eight. I purchased them for the LT-1 motor and also had a set put into the TPI that I had on the engine stand from a 90 Vette. That is what i intend to put in the 91 Silverado. The injectors woke the Impala right up and they are great, I can't imaigine what they will do for the other TPI motor.

I am putting this together with the vortec heads, 6 to 1 roller rockers, high flow tubes and the computer bumped to handle the higher flow injectors. The motor already had a roller cam in it. I hope to get a good boost out of this.

[phishfud]

I am hoping to not mess with the computer in mine. I know the TPI uses the chips, which even though I can get the stuff cheap enough to burn my own, I would almost rather do a Megasquirt standalone and have full tuneability. I may go that route, as my plans always change.

[Pyrotechnic]

Originally Posted by phishfud

I am gonna be doing a TPI swap on my 84 hopefully in a month or two. Already have the TPI setup from an 85 Camaro, which will allow me to keep my old style heads. I have the wiring harness figured out, and where I am gonna get it. My parts truck was a dual tank TBI, so gonna use the tanks from it and install F-body TPI fuel pumps. I will be using a speed density setup, and using a dual electric fant unit from a TPI f-body. I have most everything figured out, but thought i'd see if anyone has done the swap, and what kinds of other issues you may have run into. This is going on a GM crate 350 which was rated at 260hp/330ft.lb. Nothin wild, but moves my K10 pretty good. Any advice or cautions on the swap wold be great. Thanks.

You can't use a speed density setup with a 85 computer though if I remember right. 90-92 has the right computer and harness for a take out and reinstall swap. For an 85 setup you will need the MAF sensor.

[Russell]

Dunno if anything I'm about to post was already mentioned above or not, but here are my experiences:

1) Engine specs are incredibly important to pay attention to with these engines, esspecially if you don't want to mess with the chip like you mentioned. You want to have a higher compression engine with a camshaft that is designed for stock, un-chipped TPI setups. Any major cam manufacturer should have what you need. I cannot stress enough how important it is you put a mild camshaft designed for EFI in before you do your swap, your stock cam will not work well with the TPI. The biggest thing is eliminating valve overlap, get a cam with a 112 - 114 or wider lobe separation angle, short duration, and lots of lift.

2) You may want to consider upgrading to an 86 `165 ECM. The old 85 ECMs have a very slow baud rate, which makes datalogging a pretty impossible task. The 85 ECMs are a single year ECM, have a single year MAF, and single year burnoff module. The burnoff module is known to be a bit unreliable, and all three are fairly expensive to replace. Not a major task to change it out, and is well worth the effort.

3) Your dual tank switching valve isn't rated for TPI fuel pressures. It is quite likely that you'll have problems with it if you simply replace the TBI fuel pumps. Also, you may want to consider getting your fuel rail fitted with rear exit fuel line connections. It may cost a bit, but it will save you a bunch of effort lengthening the lines to reach the front exits on the stock fuel rail.

All in all, not a terribly tough swap. Keep in mind that you won't get more than 4500 rpm out of a healthy 350 with a TPI setup, and that without tuning, you'll be pretty restricted in what you can do with the engine specs. I'm personally going the way of the Gen III smallblocks. LSx engines are tough to beat, with 25 years of technological advances in fuel injection and engine dynamics under their belts

[phishfud]

I guess I should have clarified that even though the TPI setup I have is from an 85, that's all I'll be using. Getting a SD aftermarket harness and going with the 730 SD ecu. I'm pretty sure the motor I have now is an 8.5:1, and the cam specs in it are similar to what a stock TPI 350 had, although it isn't a roller block. ONe thing I didn't know is the issue with the switching valve on the dual tanks. If it won't work, no problem as I'll just run one tank. I saw something the other day about the rear exit lines, and will definately be going that route. I still have alot of parts to collect, and some figuring to do as far as the overall swap. I appreciate the input, guys.

[Jim85IROC]

Start with a TPI setup from a newer car, or at least convert to a newer style ECM. I see that Russell already touched upon the 85's limitations, but I wanted to go a bit further. The 85 ECM is primitive and difficult to modify for a different motor, like a 350. I ran into all kinds of problems getting my 85 to run well when I put my 350 in. You can't use a PROM from an 85 Corvette in a Camaro ECM because there are some differences. I found that my car ran far better when I converted to the "165" ECM that was used from 86-89. This requires only minor changes, and all of your original sensors will work. Best of all, there is a tremendous amount of support out there for custom PROMS for this computer.