TPI in a Monte Carlo SS

Monte SS 383

Not-quite-so-new-guy
Thread starter
Sep 26, 2007
26
0
Altoona PA
The 85-89 has the MAF 90-92 has the speed density. 85-88 has the 9th injector 89 eliminated it but kept the MAF. The 9th injector can be deleted in all the years you just need to have the chip programmed for it. 89 started with the VATS so if you go with one of those computers/chips you need to program around that. As far as which is best that is always the debate and can be your choice. The Speed density is faster and cleaner to set up. You can have a chip programmed around it. Just remember that at times you may have to send the chip back a couple times to get it right if you do any mods. MAF is more adaptable to the performance up-grades, and if you get the granitelli mass air flow sensor it has a adjustable pot right on it.
 

pokertramp

G-Body Guru
Aug 10, 2008
564
0
If I have a 1975 Chevy 350 4 bolt, will a 1986 LB9 305 TPI unit bolt on?

I would like to have the TPI but would also like to keep my current 350 as it has almost no miles on it. My friend can get me the whole TPI set up off a 305 with a spun bearing. The only thing it doesn't have is the computer, has all the wires.
 
Sep 1, 2006
6,687
0
Tampa Bay Area
You could bolt it on, but the center 2 bolt locations on the manifold may require a bit of modification to work. Nothing major. For an ECU, look at a Megasquirt kit as they are designed around the parameters of a GM sensor array. You probably could also use the ECU from a 2.8 MPI V6 with the PROM for a TPI 350 Camaro, but it would depend on matching it with the type of management it has to your needs (speed density or mass air). You would probably also need to use bigger injectors, and may need other mods depending on your engine's airflow needs. A dead stock TPI is a bit restrictive past around 300hp.
 

Monte SS 383

Not-quite-so-new-guy
Thread starter
Sep 26, 2007
26
0
Altoona PA
The 85-86 TPI will work. The 2 bolts did not change on those until the 87 to 88 model. They all used the 9th injector. 89 will also work but they did away with the 9th injector but all those years used MAF. If you do away with the 9th injector use the 89 set up but you will have to do away with the VATS that was placed in 89
 

86Cutlass383SR

G-Body Guru
Apr 1, 2009
720
0
Sesser, IL
I just joined a few weeks ago. Thought I'd introduce myself and my "TPI" swap.

Started out with an 84 Cutlass that had a 3.8 in it. Swapped in a 350 Chevy carbed. Had a flat tappet cam go flat and scored the crank. Instead of feeling a set-back, I decided since I was going to have to find a differant crank, it was time to build a 383.

Built a 383 with a cast steel (no-name brand from machine shop) crank and KB hyper flat-top pistons. Had a 218*/224* .495"/.502" 112* Comp retro roller cam with Summit roller rockers. AFR 190 (pre Eliminator) heads with TPIS Big Mouth base and SLP runners. 24# Accel injectors and adj pressure regulator. I also ran a Monte tank with a Cutlass filler neck soldered in. A Howell harness was used with a Granitelli 255 lph in tank pump. Hedman shorties dumped into dual cats. A TPIS level V chip was controling the 87 MAF system.

A World Class T5 was run behind it with a Centerforce 10.5" clutch and pressure plate in an 88 Camaro bellhousing. Actuated by using mid 80's Camaro pedals and the stock type hydraulic setup.

I wasn't real happy with the hyd clutch setup and had since bought a used SuperRam setup and new Aftermarket Tremec T56 trans. I removed the TPI setup and added 30# Ford SVO injectors and installed the SuperRam and then had Ed Wright of FastChips burn me a new chip for my computer. I had them burn the chip for an 89 Camaro to delete the 9th injector. I then pulled the old T5 and stabbed in the T56 along with a Lakewood bellhousing for an 83 Camaro which used the mechanical linkage instead of the hyd setup. SpeedDirect linkage replaced the stock worn-out linkage rods. A Spec Stage 3 clutch replaced the Centerforce clutch pressure plate assembly. After having the driveshaft shortened for the new T56, I had a set of 3.42 gears put in the 7.5" rearend.

This setup ran hard until a broken piston derailed added progress. :roll: Seemed like I was making 1 step forward and 2 steps back. Engine needed rebuilt yet again, the AFR heads had some pitting from the broken piston so I had them fixed which also made the combustion chamber slightly smaller. The body had more rust than I had time or money to fix... on & on.

I located an 86 Cutlass Supreme body with a 307 Olds engine that ran like *%@* but the body was straight and fairly rust-free for an Illinois car. Stripped the 84 of all good parts and I'm now in the process of putting my Claret bucket seat Salon interior in the 86 after pulling the blue bench interior out of the 86.

The 383 will get an additional .010 cleanup making it a 385 now. A Scat crank and stroker rods will replace all questionable parts along with some new pistons with a 12cc dish to keep compression around 10.1 with the added bore and now smaller 66cc heads. I am stepping up to a 230*/236* 113* Comp XFI 280 roller cam. Comp beehive springs and an AFR rev kit will now control the valves.

I am also moving up to an 11" Centerforce clutch and pressure plate. The old flywheel was a 2 piece rms 305 flywheel which needed a balance plate between the crank and flywheel to account for the external balance. My new flywheel is the correct style 400 balance and I can now run a bigger clutch.

I hope to have it mobile under it's own power again by mid - late summer. Key word... "HOPE"!!!

Sorry it was so long but I've been a long way with my beloved G-body and the ride continues as time and money permit. Once it's done I bet it'll become my daily driver. It'll probably be too da!! fun not to drive!!!

Thanks for listening and reading this far if you did.

Doug Gulley
tpiolds@yahoo.com
86Cutlass383SR
 

gasmachine85

Not-quite-so-new-guy
May 5, 2009
15
0
Anybody got a carbed lsx in their g body? that is the way to go honestly.
 

79GP6.6L

Greasemonkey
Jul 7, 2006
218
0
Upstate NY
Re:

85 Cutlass Brougham said:
Just a quick question: How can you tell a 305 from a 350 TPI? I saw one in an old Camaro on my last junkyard trip and was intrigued.

They will have 5.0 or 5.7 stamped into the back of the block above the bellhousing.

You can also look at the 8th digit of the vin. If it is a 350, the 8th digit will be an 8.
 

crucial118

Royal Smart Person
Nov 15, 2008
1,055
48
MARYLAND, DMV
Got a quick question guys. Does the computer have to get reprogrammed if you bore and stroke a TPI 350 to a 383? Or can you drive it like that without the programming and the comp sense the differences?
 

86Cutlass383SR

G-Body Guru
Apr 1, 2009
720
0
Sesser, IL
crucial118 said:
Got a quick question guys. Does the computer have to get reprogrammed if you bore and stroke a TPI 350 to a 383? Or can you drive it like that without the programming and the comp sense the differences?

That really depends on a few things. Are you running a Mass AirFlow (86-89) TPI or a Speed Density (90-92) system. If you are running SD then yes you will need to have a new chip burned.

The MAF system might be able to take the increase if you're not going too wild with the cam.

The SD system looks up fuel and spark tables based on the estimated airflow. More cubic inches will need more fuel and airflow, so all the tables will be incorrect for a bigger engine.

The MAF system uses the mass air flow sensor to actually measure the incoming air and is more tolerable of change if they're not to drastic.

Realistically, to get the best performance and mileage from your engine, then a new chip is highly recommended. And I'm not talking about a Hyper Tech type chip. Buy from someone who can burn a custom chip for *your* engine.
 

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