MTPFI-MAF

Ok I haven't done much to my car since I upgraded the 870 to a 165, in fact I am still Need to buy a V8 Memcal to make sure the 165 swap is ok but I am a Beliver.

Any ways while I wait on the time and money to work on mine I have a friend with a Tubbed Vega and we are in the middle of Building a 383 for it. He would like to go TPI Fuel Injection but the cam he decided on Probally wouldn't be a good choice for a TPI system even though We will be burning our own proms.

This is the cam that he has Pick out when he was going to put a Holley DP 750 on it.
What cam would any one recommend that would be Better for a TPI.

Comp Cams 294S
Solid Flat Tappet
Duration@.050: Int:248 Exh:248
Lift w/1.5 rockers Int: 0.525 Exh:0.525
LDA: 110 Degrees.
The Problem I see with this cam is being a solid Flat Tappet is will be noisy and the Knock Sensor will go crazy, also the LDA being 110 degrees wouldn't it be better if it was 112 degrees on a TPI.

Enging Combostuff in Blue has already been purchased
Heads: AFR 195
Intake: Victor Jr. (carbed) HSR(Fuel Injected)
Crank: Eagle Forged 383 crank
Rods: Eagle SIR 5.7
Pistons: Forged SRP Flat Tops Roughly 9.7:1 compression

any recommendations

VetNutJim

That's a LOT of duration @ .050 for a TPI engine.

The engine will be induction limited by the flow capability of the TPI intake system and never get up to the RPM range to match the capability of the camshaft.

Try to drop duration @ .050 back to 210-225 degrees.
The lift on that cam is quite a bit also.
Was that lift at the lifter or valve lift with a 1.52 rocker arm?

Lift is always good ...but..
the caveat is you will have a harder time setting up the valvetrain geometry correctly with lifts over a half inch versus lifts in the .400 to .499 range.

110 LSA isn't going to be a problem. It will affect the cranking cylinder pressures but 110 will work with TPI.
Stock TPI cams are 112 LSA.

Unless this will be a 'off road' HIGH rpm engine that would be just a wee bit tooo much camshaft.

TPI looks great and runs good but IT IS NOT A HIGH RPM intake system.
5000-5500 RPM is about all it's good for.
There's no need to run a camshaft that makes power at 6000-7000 RPM with it. You WON"T be happy with the results, the engine will be a dog and soft on the low end just where you want it to feel good. Bad karma.

Hope this helps.

MTPFI-MAF

Acutally I forgot to mention that the Fuel Injection Will Be running a Holley Stealth Ram or A MiniRam II I Had this exact engine about 3 years ago in a 84 camaro with a Victor Jr. Intake and A Barry Grant Speed Demon 750 carb and Shifted it at 6200 rpm and on the dyno it produced 480 H.P With Shorty headers and Small Exhaust. Before I could upgrade the Exhaust I lost the car in a divorce.

Well Now My Buddy wants this Kinda power but Also Fuel Injection. I have seen a couple of TPi engines with solid Flat Tappet cams but the knock sensor was disable, to me disabling the knock sensor is taking away a tuning aid and a safety net.

I figured that with a TPI set up using the HSR or Mini Ram that the lift and Duration would probally be different, Just want to keep the Torque and H.P about the same with Fuel injection as they were with the Carb.

? Any one putting out 450-500 HP at the Flywheel

MTPFI-MAF

anybody

oppinions please.

Grumpy

Can you tell me the difference in going with a carb, and distributor, with no knock sensor vs EFI with no knock sensor?.

The knock sensors are acoustic, and such not perfect. Missing the tune, can have disasterous results even with a functional Knock Sensor.

MTPFI-MAF

Wow I never thaught to look at it that way. No if I Disable the knock sensor in the Prom Will it still show knock Counts while Data Logging, it just wont Pull any timing out. Is this correct. Do you see any other reason why We would have a problem running a Solid Flat Tappet Cam in A Fuel injected Engine.

I like how you make things Simple

Thanks

Grumpy

Personally I'd go thru all the ESC stuff, and negate it.

The problem is going to be seeing how the MAF reacts to the various levels of reversion from that big of cam.

MAF systems use a LV8 calculation for figuring the timing, so you can get into odd situations, in how the load is being calculated vs how much reversion is goofing with things. It's really application specific, IMO. Some guys tune right around it, some have to play alot of games to get it ironed out.

MTPFI-MAF

Well We are probally going to go with A SD System on this car.