RonB1979

I just did a 305 TBI to 350 TPI swap and it doesn't seem like there is anymore horsepower or torque. In fact it seems like there is less torque. I could barely do a burnout before now I don't think I can even do one. Anyone know why this may be.

vetteoz

iTrader: (13)

You don't mention anything about what year ( fill in your profile )
or condition of the engine
or if you have installed other parts that might be different on a TPI engine like the heads and cam ?

RonB1979

My bad. The car is an '89 and the TPI engine is also an '89. The engine was just rebuilt and has the factory cam and heads. Nothing changed on the car but the motor. I have an MSD blaster coil, MSD wires & cap, K&N air filters, headers with 2 1/2" custom exhaust & no cat, flowmaster muffler, & 3.42 gears.

Guest

Ecm
injectors
"actual" C.I.
compression test.
INJ parts ohm-d out
fuel pressure
timing
ect...

RonB1979

All I know is that the motor was rebuilt and put in my car by someone else and when I picked up the car it didn't seem any different than when I dropped it off. It just looks better now but I didn't have all that work done just to look better.

vetteoz

iTrader: (13)

Sure you actually got a 350 underneath the new TPI?
A coat of paint can hide lots of things................
Checked the block numbers to confirm it is what you paid for ?

vetteoz

iTrader: (13)

What about the TPI wiring and computer ,
not to mention should have had to drop the tank to install a high pressure fuel pump that the TPI requires ?

gbettner

iTrader: (2)

Any way to post some pics?

Like above post stated, If it was done right you should see evidence of rearend and tank being dropped for high pressure pump. Would have to swap wire harness or modify existing harness. ECM would have to be swapped out. Throttle cable and fuel hardlines changed. I'm sure I'm forgetting something but it's a big job. I just did the exact same swap and my 89 Iroc is a beast now. I can kick it down in 1rst gear going 20mph and light up tires well into second gear on a rough paved county road. Wish it was plated and insured so I could try out a city street.

Sometimes it's hard to get at block numbers but an easy way to see what size heads are on it is take off oil fill cap and shine a flash light down in it. If it has 305 tbi heads I think the last 3 numbers on the casting # would be like 1887 or something. A 350 tbi head would be "193" on last 3 numbers. Not sure what the casting numbers for 305 and 350 tpi are though off the top of my head. Maybe someone who knows will chime in.

RonB1979

I know for sure its a 350. I changed the ecm, harness, fuel pump and everything. It could still be the wrong fuel pump though. I'm going to take it to another shop to make sure they hooked all the vacuum lines and wires up right and have my fuel pressure checked. Just wanted to ask people on here before I do all that.

slowsi

iTrader: (2)

make sure all your injectors ohm out correctly...I was down an injector and it ran ok..but down on power

RonB1979

Could it be possible that my injectors are plugged in wrong? I labeled the harness and took pictures before I unplugged them but I don't know if the shop plugged them in correctly.

hellz_wings

iTrader: (2)

You have the right PROM for a 350? (if it was a 350ECM, it should be okay..).

Guest

You had a shop do the swap.............

RonB1979

Yes I had a shop rebuild the motor and do the swap. I have to take it to another shop to have some other stuff checked out. I just figured I would see what other Camaro guys thought about it.

vetteoz

iTrader: (13)

Just going from a 305 to a 350 should have given you a noticeable SOTP improvement
Too many variables that you need to check and confirm 1st before any relevant comment can be made

gbettner

iTrader: (2)

Good point!

RonB1979

I just noticed that my car only lacks power in overdrive. If I take off in 1st gear I can spin the tires and get sideways. I take off in overdrive nothing happens. Is that just the way 700r4 is or could it be my TV cable needs to be adjusted? Its not a race car I just want to be able to spin the tires every now and then without having to manually shift every time. What could I do to achieve this?

vetteoz

iTrader: (13)

So what gear does it start in when the lever is in O position? ( count the upshifts )


Have you set it correctly?
http://sethirdgen.org/tvcable.htm

Cable only adjust the shifts , not what gear the car starts in.

RonB1979

It starts in 1st it just lacks power I didn't know if its because its shifting into 2nd to quick and keeping the rpms down or what I was reading other posts on here about the TV cable and they said if its not adjusted right the car would be sluggish that were I came up with the idea

danclemts

iTrader: (1)

http://static.summitracing.com/globa...structions.pdf

vetteoz

iTrader: (13)

So make sure the cable is set correctly and see what it does.
Obviously if trans is in 2nd it is not going to pull the same as in 1st.

Of course you realize that the 3.07 1st gear ratio doesn't let it pull far in 1st (unless you can pull some revs which the TPI won't allow )
then there is a big step up to the 1.62 2nd gear ratio.

RonB1979

Now my freshly rebuilt motor with less than 200 miles on it has low oil pressure. The shop that built it said its probably the cam bearings. Since my engine will be out and taken apart again should I change the cam. If so what should I use and would I need a custom prom for it?

RonB1979

Hopefully somebody can help he. My car is running really hot. The shop that did my swap hooked my fan to the switch in the head. Since I only have the single fan shouldn't it run off the ecm or am I going to need the dual fan? Right now my fan doesn't turn on until 260 degrees before I did the swap it turned on about 220 I think. Could I just use the fan switch from my old 305? I need help asap because I cant even drive my car like this.

Guest

Wire fan to a switch, then to the battery.

Tuned Performance

iTrader: (92)

Have the ecm control the fan relay, The default setting in the memcals reprograming is on at 226f but that can be changed easily with reprograming. Use c1 of the ecm assuming the is a 165 ecm to control the ground side trigger of the fan relay like the cylinder head temp switch is wired. the temp switch can be use still for a backup if desired just tie onto the wire.

RonB1979

I thought about that only I'm not going flip a switch on and off all day and I paid thousands of dollars to have my engine swapped out the shop should have it working the way its supposed to be.

RonB1979

Thanks I paid a shop to do my motor ill take it back to them and have them do this

hellz_wings

iTrader: (2)

I agree they should have done this.

Tuned Performance

iTrader: (92)

If you want me to post the schematic lmk, Take it back if you paid to have it done.

RonB1979

I would like to see the schematics just in case the shop gives me a hassle or something. I just jumped the fan so it would run when the keys on just to see if it would cool it off. I let the car run for 20 minutes and it stayed right around 220 degrees.

Tuned Performance

iTrader: (92)

RonB1979

Thanks

hellz_wings

iTrader: (2)

Your TPI motor will run at its best performance-wise at 180, not 220.. I have TPI with 180 T-stat, dual fans (from a 89 trans am), new GM air dam.. It stays anywhere from 160 to 190 (never reaches 200 and barely ever reaches 160)

vetteoz

iTrader: (13)

The usual backyard way to burn your car down

RonB1979

Some guys tell me to run the lower thermostat & fan and other guys tell me not to. I don't know what to do. I just want to start with getting my car to run like it was designed to then I can go from there. I have thousands of dollars into this thing and I cant even drive it. I just want to be able to drive it for the rest of the summer then I can add stuff and tune it over the winter.

Guest

Been driving it for years.

jjcuff1

Well this sucks I know. Sounds like your motor was built right (except seals?) from your comment about being able to smoke tires in 1-2 shift but OD it dogs.

Then you said it is running hot.

It could be a fuel problem. You are runign lean? new fule filter right pressure. I would invest in wideband for $200 and read you AFR.

Did they reuse the 305 knock sensor? the 305 injectors? The afr will let you know if your lean/rich

RonB1979

I just brought it back to the shop and they redid the seals now I just need to fix the overheating problem so I can drive it

vetteoz

iTrader: (13)

Start by working out why the fan is now coming on at 260 instead of the 220 it used to , what did the shop change?
( is your temp gauge accurate; tested it with IR gun or another temp gauge to confirm ? )

or install a fan switch like this one
http://www.racerpartswholesale.com/p...n_Accessories2

and wire the relay without ECM fan control so the fan will be like the early cars and run automatically without any extra wiring or switches.

RonB1979

I had my fan wired to the ecm now it turns on around 225. I'm still looking to get some more low end torque though. I read somewhere that you have to change the torque converter with a bigger cam. Would changing the converter with the stock cam do anything for me? If so what toque converter should I use and how much would this actually help? Would this be something worth doing or is there anything else I could do?

Johnny Blaze

iTrader: (15)

Stock cam = stock converter.

You need to find out what you have.
What engine, what cam, compression, heads, injectors, etc...

Was the ECM changed to match the 350?

If you actually have an l98 spec 350 it should feel noticably quicker then the 305.

Double check timing too.

RonB1979

Evererything is original just new rings and original heads where redone. Yes the ecm was changed and it is an l98 350. I only driven it a couple times a year ago with the 305 so I don't remember how it performed. All I know is that I can barely keep up with my friends elcamino with a stock 350 and a friends monte carlo with a 305. My car is a lot lighter and has 3.42 gears. I only did a tpi because they look good in the camaros. For the amount of money I spent I could have just built a carbed 400.

hellz_wings

iTrader: (2)

Agree with Johnny about timing. My initial timing is at 10* but it's also set at that in the PROM (the chip inside the ecm that is removeable that you can edit if you have the hardware and software like TunerPro). I remember putting timing back to 6* and it felt like a dog. I laughed at how much power I lost, so I put it back to 10* and all felt right again. Maybe you should try putting it at 8 or 10* (ofcourse carefully monitoring for detonation) and getting a tune for that? Also:

1) what injectors are you running? It might have 19lbs injectors, good for a 305 but not for a 350, you will need 22lbs minimum for a 350..
2) What year TPI did you install on top?
3) Air filter assembly is the stock TPI one?
4) Throttle position sensor gets high enough volts at full throttle?
5) Also, how big is your exhaust? Headers? Ypipe? They all match up properly? Cat maybe is clogged?

Lots of things to check ..

RonB1979

Everything came with my engine. Injectors, ecm, its all for the 350 and its an 89. I have the stock air intake but I cut the bottom out and installed k&n filters. I have headers with a 2 1/2" exhaust y pipe flowmaster muffler and no cat. I had the exhaust done before the swap and told them to do 3" just in case I put a bigger motor in but they did 2 1/2" everything seems to be working fine I just want to get a little more torque that's why I did the swap.

hellz_wings

iTrader: (2)

I would look into initial timing. What's it set at now? stock is 6* initial advanced on the distributor.. If you set to 8 or 10 it might run better.

And yeah a 3" would have been better..

Johnny Blaze

iTrader: (15)

ECM throwing any trouble codes?
Dial in timing, check and dial in tps as well.

hellz_wings

iTrader: (2)

TPS voltage at idle should be 0.54v. Full throttle is somewhere around 4.00v IIRC (here is a link to adjust it, with pics: http://www.iroczone.com/2009/10/adju...on-sensor-tps/)

RonB1979

I just put 4.10 gears in my car and that made a big difference. Now I just need to eliminate the rear wheel hop and it should spin the tires pretty good. I also think I need a new distributor because sometimes it idles erratically but other than that it performs a lot better now. Thanks for all your help.

rusty vango

stay away from "shops" if you want it right YOU have to do it.

rusty vango

THIS is why to stay FAR away from SHOPS!!!!!