TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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I need some help on my next project that I am going to do on my 87 Camaro. I have finally installed TPI on my engine so now the cars runs great. I had carburettor before and I can really tell there is good difference already..
But as most people we can't get enough power. I don't want any extreme engine at all..Because I want to have a OK gas mileage also.
So if you understand me correct: The best performance engine for the best gas mileage/usage....You know about the horrible prizes in norway and this is a daily driver car...Not a race car...
I was thinking of something like this:
* Port and gasket match: heads, plenum and intake
* New camshaft
* Headers
* New valve springs etc.etc
Can someone please help me out what to buy??..I have a roller cam if anyone wonders...I know there are a lot of choises but I just want a little help..Thanks
put them all on and take it to your local speed shop dyno. make one chip for speed and power and make a 2nd for best possible gas mileage and emissions. its an easy switch when you want to play hard, put in the hard chip.
kevin said that he can do a chip that will do both.
Last edited by tony_cogliandro; 05-05-2009 at 11:30 PM.
I just spent some time evaluating cams for my swap ( 305 L69 to TPI). Finally decided that the LT1 cam ( or LT4 if you can find one) was the best overall chioce for me. Gave good lift and duration, with plenty of LSA for the computer. I found most aftermarket cams have too much lilft or duration to be friendly with the stock heads.
The Crane 2031 or Crane 2032 were also good choices, but Crane recently closed their doors, so I was concerned about warranty, etc.
Comp Cams 08-300-8 is not a bad choice, but with .480 lift on the exhaust, it might be close on max lift. Lunati 554760LUN is also a good choice. Lift is just about max, as is the duration. Howard Cams 180225 is a good lower cost alternative, as is Elgin 1040.
Last edited by darbysan; 03-24-2009 at 01:20 PM.
Reason: Cat hit keyboard!!
I just spent some time evaluating cams for my swap ( 305 L69 to TPI). Finally decided that the LT1 cam ( or LT4 if you can find one) was the best overall chioce for me. Gave good lift and duration, with plenty of LSA for the computer. I found most aftermarket cams have too much lilft or duration to be friendly with the stock heads.
The Crane 2031 or Crane 2032 were also good choices, but Crane recently closed their doors, so I was concerned about warranty, etc.
Comp Cams 08-300-8 is not a bad choice, but with .480 lift on the exhaust, it might be close on max lift. Lunati 554760LUN is also a good choice. Lift is just about max, as is the duration. Howard Cams 180225 is a good lower cost alternative, as is Elgin 1040.
Thanks..I appreciate your tips...I have been looking on all of those cams myself actually, but I am not an expert in camshaft yet so I don't know excacly what is maximum lift compared to the lobe seperation and so on..And how to get an OK idle and also a good performance of the cam...
At a very basic level, increasing Duration moves the HP toward the higher end of the Rev Range. Get much bigger than 208 /214 duration, and you will see a decrease in low end torque, which is what you use the most in daily driving.
Increasing lift increases power and torque, but you are limited to what your head can handle. I have been using .470 as a max for stock 305 heads. I have never really gotten a good answer if more is possible or not, but in reality the flow of the heads would probably be a limiting factor to getting any more performance out of more lift.
LSA or Lobe Seperatoin Angle, affects idle the most. 112 to 117 is what we see stock from GM. Get below 112, and your idle will get very rough, and the idle vacumn will be low. For TPI, low vacumn equates to poor performance from the computer, as it gets very confused.
With all this factored in , the LT1 gives you about the most lift and duration you would want, with good LSA, and are usually found at a reasonable price. Just beware- I bought 4 off of ebay before I got one I could use.
See my garage for what I have done to the same engine. My cam works great. I am just in the process of getting a custom PROM chip. Then the engine and drive train is finished.
At a very basic level, increasing Duration moves the HP toward the higher end of the Rev Range. Get much bigger than 208 /214 duration, and you will see a decrease in low end torque, which is what you use the most in daily driving.
Increasing lift increases power and torque, but you are limited to what your head can handle. I have been using .470 as a max for stock 305 heads. I have never really gotten a good answer if more is possible or not, but in reality the flow of the heads would probably be a limiting factor to getting any more performance out of more lift.
LSA or Lobe Seperatoin Angle, affects idle the most. 112 to 117 is what we see stock from GM. Get below 112, and your idle will get very rough, and the idle vacumn will be low. For TPI, low vacumn equates to poor performance from the computer, as it gets very confused.
With all this factored in , the LT1 gives you about the most lift and duration you would want, with good LSA, and are usually found at a reasonable price. Just beware- I bought 4 off of ebay before I got one I could use.
Actually that was a good explanation of it...I understood a little more now about the camshaft...I know the basics of course on camshaft and how they work...That is a easy to understand I think.
I have also been looking for a while on Ebay and have found a few cam's but everything is performance camshaft's to LT1 engines..And I guess that isn't really what I am looking for....
How about this Comp Cams 08-300-8...Is that a good choise??...I have found that camshaft for a reasonable prize so I think that would be my next bet....
As for headers i think I will try Hoooker 2055HKR...Are they a good choise??..I have heard a lot of good comment on them...
I also want a high flow catalytic converter...Thinking about Catco 9118.
And porting the intake, plenum, runners and heads will of course be something to do..
1. Do you want a smooth idle or can you live with a rough idle?
2. Can you accept loosing fuel economy for the sake of increased power?
3. What is more important high horsepower racing at 5000 rpm or the ability to launch from a stoplight and being pushed back in you seat?
Consider these cams from comp cams.
HYDRAULIC ROLLER-For throttle body 305 Hyd. Hyd. 1000 to 5000 08-500-8 XR258HR 258 264 206 212 .480 .488 112°
or 350, very good economy and power.
HYDRAULIC ROLLER-Best in 305 or 350 Hyd. Hyd. 1200 to 5200 08-501-8 XR264HR 264 269 212 218 .488 .495 112°
tuned port injected engines.
HYDRAULIC ROLLER-Good for TPI 305 Hyd. Hyd. 1500 to 5500 08-502-8 XR269HR 269 276 218 224 .495 .503 112°
or 350 with upgraded exhaust.
Needs programmer.
HYDRAULIC ROLLER-Needs modified TPI Hyd. Hyd. 1800 to 5800 08-503-8 XR276HR 276 281 224 230 .503 .510 112°
w/injectors, plenum, runners, exhaust and
programmer, 2000+ stall.
Or possible these cams from comp cams.
HYDRAULIC ROLLER-Good for mileage Hyd. Hyd. 600 to 4600 12-407-810 XR252HR 252 258 200 206 .472 .480 110°
and for towing, smooth idle.
HYDRAULIC ROLLER-Strong torque, Hyd. Hyd. 1000 to 5000 12-408-810 XR258HR 258 264 206 212 .480 .487 110°
good mileage, stock to mildly modified
combinations.
HYDRAULIC ROLLER-Mild performance Hyd. Hyd. 1200 to 5200 12-412-810 XR264HR 264 270 212 218 .487 .495 110°
applications, very good mid-range,
3.23-3.73 gears.
HYDRAULIC ROLLER-High performance Hyd. Hyd. 1600 to 5400 12-422-810 XR270HR 270 276 218 224 .495 .502 110°
application, largest with stock
converter, noticeable idle.
HYDRAULIC ROLLER-High performance Hyd. Hyd. 1900 to 5600 12-423-810 XR276HR 276 282 224 230 .502 .510 110°
street machines, 2000+ stall,
gears, choppy idle.
HYDRAULIC ROLLER-Great for street Hyd. Hyd. 2200 to 5800 12-432-810 XR282HR 282 288 230 236 .510 .520 110°
machines, needs intake, headers, 2500+
stall, and gears. Mildly rough idle.
HYDRAULIC ROLLER-Street/strip Hyd. Hyd. 2500 to 6000 12-433-810 XR288HR 288 294 236 242 .520 .540 110°
applications, 9:1 CR, rough idle intake,
headers, 2800+ stall, gears.
HYDRAULIC ROLLER-Street/strip Hyd. Hyd. 2800 to 6100 12-443-810 XR294HR 294 300 242 248 .540 .562 110°
applications, 9.5:1 CR, intake, headers,
3000+ stall, gears. Rough idle.
HYDRAULIC ROLLER-Pro Street/bracket Hyd. Hyd. 3200 to 6200 12-444-810 XR300HR 300 306 248 254 .562 .580 110°
racing, 10:1 CR, 3500+ stall, good
intake, headers. Very rough idle.
When you have answered the about questions in your mind, then contact Comp Cams for an opinion from cam experts.
1. Do you want a smooth idle or can you live with a rough idle?
2. Can you accept loosing fuel economy for the sake of increased power?
3. What is more important high horsepower racing at 5000 rpm or the ability to launch from a stoplight and being pushed back in you seat?
Consider these cams from comp cams.
HYDRAULIC ROLLER-For throttle body 305 Hyd. Hyd. 1000 to 5000 08-500-8 XR258HR 258 264 206 212 .480 .488 112°
or 350, very good economy and power.
HYDRAULIC ROLLER-Best in 305 or 350 Hyd. Hyd. 1200 to 5200 08-501-8 XR264HR 264 269 212 218 .488 .495 112°
tuned port injected engines.
HYDRAULIC ROLLER-Good for TPI 305 Hyd. Hyd. 1500 to 5500 08-502-8 XR269HR 269 276 218 224 .495 .503 112°
or 350 with upgraded exhaust.
Needs programmer.
HYDRAULIC ROLLER-Needs modified TPI Hyd. Hyd. 1800 to 5800 08-503-8 XR276HR 276 281 224 230 .503 .510 112°
w/injectors, plenum, runners, exhaust and
programmer, 2000+ stall.
Or possible these cams from comp cams.
HYDRAULIC ROLLER-Good for mileage Hyd. Hyd. 600 to 4600 12-407-810 XR252HR 252 258 200 206 .472 .480 110°
and for towing, smooth idle.
HYDRAULIC ROLLER-Strong torque, Hyd. Hyd. 1000 to 5000 12-408-810 XR258HR 258 264 206 212 .480 .487 110°
good mileage, stock to mildly modified
combinations.
HYDRAULIC ROLLER-Mild performance Hyd. Hyd. 1200 to 5200 12-412-810 XR264HR 264 270 212 218 .487 .495 110°
applications, very good mid-range,
3.23-3.73 gears.
HYDRAULIC ROLLER-High performance Hyd. Hyd. 1600 to 5400 12-422-810 XR270HR 270 276 218 224 .495 .502 110°
application, largest with stock
converter, noticeable idle.
HYDRAULIC ROLLER-High performance Hyd. Hyd. 1900 to 5600 12-423-810 XR276HR 276 282 224 230 .502 .510 110°
street machines, 2000+ stall,
gears, choppy idle.
HYDRAULIC ROLLER-Great for street Hyd. Hyd. 2200 to 5800 12-432-810 XR282HR 282 288 230 236 .510 .520 110°
machines, needs intake, headers, 2500+
stall, and gears. Mildly rough idle.
HYDRAULIC ROLLER-Street/strip Hyd. Hyd. 2500 to 6000 12-433-810 XR288HR 288 294 236 242 .520 .540 110°
applications, 9:1 CR, rough idle intake,
headers, 2800+ stall, gears.
HYDRAULIC ROLLER-Street/strip Hyd. Hyd. 2800 to 6100 12-443-810 XR294HR 294 300 242 248 .540 .562 110°
applications, 9.5:1 CR, intake, headers,
3000+ stall, gears. Rough idle.
HYDRAULIC ROLLER-Pro Street/bracket Hyd. Hyd. 3200 to 6200 12-444-810 XR300HR 300 306 248 254 .562 .580 110°
racing, 10:1 CR, 3500+ stall, good
intake, headers. Very rough idle.
When you have answered the about questions in your mind, then contact Comp Cams for an opinion from cam experts.
Thanks again for the information...when it comes to your questions:
1: I want the idle to be about fine and not very rough..I hate when it is a problem that my engine stalls when slow city driving is appearing..
2. Of course I know the economy will be less if I am using a new cam but I want it to be about normal...10litre per 100/km....
3. I want to be pulled back in the seats..in other words LOW RPM torque...That is definetily the best choise here in Norway.
So you want a cam that will not effect the idle very much, does not reduce fuel economy very much and which is torque biased.
Next you mentioned you are going to port the existing heads. Which heads do you have? The selection of a cam, to some degree, is also influenced by other parts of the fuel air intake system. All these parts need to work together. You will need to remove the valve covers and find the casting numbers. This maybe another useful piece of information to provide to the camshaft experts. The numbers may end in the last three numbers being 081 or 187 it this was a TPI engine.
For headers try full length if you are not going to lower the car. Fitment maybe an issue in the engine compartment. Hooker, Hedman Hedders and others both make a good selection of headers. This issue has probably been addressed over on the exhaust board. Search the exhaust and TPI boards for header threads.
All this may lead you to the following camshafts listed above 12-408-810, 12-412-810, 08-500-8, 08-501-8 or possibly 08-502-8. I am using the 12-408-810 which works well. However, do discuss this Comp Cams. Their technicians will be only to happy to advise you on what camshaft to use.
Also at this time consider new fuel injectors and an adjustable fuel pressure regulator as you will have the intake base manifold off and now is the time to do this if you can afford it. Ford Motor Racing 19 lbs.hr injectors and the Holley regulator are what most people use here. I have both of these products on my TPI engine.
Also, at this time have your entire TPI system checked for vacuum leaks.
