Ok, some of you (might?) remember I posted here earlier some questions about my engine project( 1988 automatic corvette). My goal is to make a streetable car around 400-450hp utilising stock parts as much as I can. I already have all the free/easy mods, SLP cold air intake with big mouth, magnaflow cat-back and no cats, Heddman headers. My plan as today is this (remember this is 2 year plan):

-Engine is going to be 355 (strictly cost basis becouse 383 is going to cost 1400$ more)
-Cam LPE 74219 (Lift seems to be enough for nice lumby idle)
-AFR 195cc heads with 68cc chambers (I want GOOD heads)
-LPE big mouth intake manifold (I would have liked to use the stock manifold ported but it seems that there is not enough material for porting)
-LPE High flow runners
-FULLY ported stock L98 Plenum to match high flow runners and 52mm Throttle body.
-Hardened transmission with Shift kit
-Converter 2300-2500 (LPE 74219 is going to produce power around 2000rpm right? Then 2300-2500 rpm converter should be just correct)
-Hardened rear with 3.73 gears

Now the questions are, do I need bigger injectors and fuel pump? I already have cleaned stock injectors. What about water pump? Do I need high flow version? And same goes for the oil pump?
How does that setup in general looks in your eyes?

Thanks for your info

 

Are you talking 400 RWHP or crank? Either way I think you're going to be sadly disappointed. The super ram or mini ram will flow enough air for that kind of power. I could be wrong but the intake setup you are talking about seems like a glorified TPI, which will still choke in the upper RPM's.

The heads, that's a pretty big chamber so you'll have to build the engine with compression in mind to gain some of that back or it'll be a terrible performer. Also the heads have a fairly large runner volume which is going to cost you some low end torque. If the heads give up low end and the intake costs you upper end you really won't be really happy with it.

Don't get me wrong, it should make good power, but it's going to fall way short of the 400 HP goal.

 

With a modified TPI on a 355 SBC you may hit 375-380chp.

And yes the heads are pretty large for a 355.

You could build more HP if you give up low end torque and move the torque peak up far enough. But that will take some work on the valve train and even on the bottom end.

Also you should be thinking about true duals as a single cat won't flow enough.

 

Strongly suggest you rething this approach. Your not going to hit the numbers you are looking for w/ these parts. You will need many more cubes or forced induction for those #'s. You collection of parts are close, but not ideally suited for the whole combo. I'll suggest the heads are too big,... that and the BMouth will cost you much low end TQ. End result,... you will have a screamer, that will leave you disappointed on the street.
The WP,.... stock version will work fine. Oil pump,.. there are many threads about it. You wont' need a HVol version. HPress,... you don't need it, but won't do any harm if you were to use one. (Cost you more gas & a lil pwr.)
Your spending a good chunk here in parts.

 

Thanks for info guys, I welcome critisism So what you're saying I should aim for more cubes? Or if I'll stay with 355 I need smalled heads, like AFR 180cc for example?
Do you really think the TPI wont flow enough when fully ported? Maybe you're right and I should get the Superram. If this is not ideal combination, what would you do differently?

 

Take a look at Vic'89's mods as he is now building about 330chp and running mid 12s with stock heads & cam and modified TPI intake (Accel base with AS&M LT runners).

If he adds ported stock #113 (or small AFT) heads and a nice cam (maybe ZZ9 or 219) he can expect another 55-60chp, after some tuning. That would put him in very low 12s or even very high 11s at close to 390chp. With a 355cid setup he might see 390-395chp. True duals with 2 1/2"-3" pipes and dual cats might bring him in at 400chp. When you get near 400chp you simply cannot push enough air through a street legal single pipe exhaust system.

From what I've seen and heard he has one of the strongest running L98 out there, so this would be the most you could reasonably expect from a modifite TPI setup on a NA 355cid motor.

Considering that most bone stock TPIs will run around 14sec, getting one to run 12sec flat is a big jump in performance.

If you stroke to 383 you can expect about 9-10% more power, which would put you into your stated target band. This would also dictate somewhat differnt components from a built 355. In either case you will likely need larger injectors (I think stock 22lb/hr top out around 330-350chp), but I'm not sure about our stock fuel pump's capacity.

It partly depends on where you want to build the power; do you want TPI torque or a LT1 screamer?? Is the additional 30-40chp worth the bottom end buildup of a stroker??

Also, with an A4 3.73s might be a little much, especially with a modified TPI setup; maybe 3.54s would be better for street/strip.

 

Not wanting to start any arguments here, but if you are looking for 400 at the crank, it is possible with a performance TPI setup. Not sure about 450, but 400 has been done.

http://forums.corvetteforum.com/member.php?u=6688

 

I think you can acheive 400chp with that setup. However, I don't think that setup you have listed is good. I would forget the 3.73...it's a waste of time to have 3.73s with a TPI motor, I would just get a good convertor with at least 2800rpm stall.
You will need 24# injectors, and I would save your money on big tube runners, base and plenum. Look for a used superam and you will thank yourself.

 

Unless you are going for the stealth TPI look, for the money you spend on ASM or LPE runners and porting the plenum, you're not that far off from the SR. Plus, the SR will accomodate bigger cubes if you ever decide you need more hp while the TPI setup is pretty much done.

 

Hmm... Ok what if..... I keep 355 in my plan and port the stock heads, add LPE 219 cam, port match stock intake manifold ja L98 plenum to 52mm tb and large tube runners. I know this combination is way below 400hp (crank)) but I think it is very cost wise plan and it's MUCH cheaper than what I originally posted.

About those gears, I have a feeling also that 3.73 might be too much gears for automatic. Maybe I should go for 3.54 gears instead.