I'm kicking around the idea of doing some kind of upgrade to my 350 TPI. I have read that the stock HP rating is about 230. Now it may just be me, but when a supercharged 3.8L V6 has a HP rating higher than my gas guzzler, we have a problem. I am planning to pull the engine out of the car so the only restriction is pretty much money. Other than a stroker kit or forced induction, pretty much nothing is not of the picture (except a crate motor). I was thinking about a cam and maybe pistons. I'm looking to get somewhere between 350 and 400 HP out of it, but the key thing here is that it has to be reliable. I wouldn't mind bumping up the comp. ratio, but I've heard that the most I can do is about 10.8:1 and still run pump gas. This project is definately still in the dreaming stage so any ideas or suggestions would be helpful. The last thing thats kind of an inspiration is the new GTO w/ a 350 and 350 HP. I mean if GM can do it naturally aspirated, why can't I? Oh yea...will my dream blow up my T5?

 

If money is limited, this is the approach I would take.
1) How many miles on the engine? Do a leakdown test. If that checks out..
2) Have the heads ported, along with a good valve job.
3) Install a good TPI compatable cam, with matching springs.
4) New timing chain set.
5) Try to find a good deal on a Big Mouth base, or SuperRam base, and go with large tube runners. If you can get a complete S/R, or Miniram at a good price, you can take that route.
6) Edelbrock headers are easy to incorporate into your exhaust, as compared to longtubes. This is just a starting point, and these mods should get you into the mid to low 13s.

Dont go over 10:1 on the C/R with steel heads.

 

Theres 152000 mi on the car, but from what I understand, the engine is either new or just has been babied all its life. I won't know the condition until I take it apart. What do you think about the gear drive timing sets as opposed to a chain. I see they're a little more expensive (about 3X as much as a chain) but is that extra $ worth it? I'm going to have to do some research before I understand what your talking about here:
"5) Try to find a good deal on a Big Mouth base, or SuperRam base, and go with large tube runners. If you can get a complete S/R, or Miniram at a good price, you can take that route."

I do know that the runners and intake components have all been ported and polished, does that do anything worth while, or should I still try to find bigger runners?

 

If the intake base (part that bolts between the heads) is stock, it would need work to flow some decent numbers. There are aftermarket bases that will accept stock runners, and large tube runners. The SuperRam is used with the base style intake, but its runners and plenum (box on top), are entirely different. The MiniRam is a one piece manifold that has the runners incorporated in it. The M/R is a shorter runner design, used for higher RPM power. If I could grab one of the MiniRams, I would, because they are easier to install, and work on.

With 150,000 miles on the engine, you might want to reconsider what you plan on doing, unless you want to do a rebuild. You can do your thing though, and if it should let go, you might or might not damage some of your external parts. most likely the rings would loose their seal.

If I were to do it, I would do the rebuild on the rotating assembly, knowing the high miles are there.

 

That is solid advice no matter how well the engine was "babied".

 

Yea, if it was a 65,000 miler, I would just make sure the cylinders and rings were still doin their job. Thats alot of miles though.

 

Very good point. Will the manifold really make that much of a difference? I'm not doubting you, I'm just really supprised. When I got the car, I remember the previous owner saying that he took the heads off and the cylinders were still cross-hatched. He basically kept the car as a show car, and didn't drive it much, but even still, a 152K motor with crosshatches? Something doesn't add up.

 

Well, thats your call then. If thats what HE SAID, I would like to know for sure myself. But when you take your heads for the mods...youll know.

 

TPIS sells an airfoil for the throttle body that is claimed to give 10 hp.

 

Like I said in the begining, of my post, this is more of a brainstorm session than anything else. I really appreciate the input, and will most definitely take it into consideration. Up until now I knew of 3 relatively easy ways to get power: 1) Blower 2) 15:1 compression 3) Really big motor. And speaking of really big motors, brutalform, your running about a 427 right? So what kind of specs are you pullin' with that beast.
BTW the 15:1 came from a friend w/ a 10.02 sec 502 Nova Nat. Asp. Without using the nitrous

 

Now, now, Floorguy, were not trying to advertise for TPIS now are we?

 

No Mike ..Actually its a 436.

 

Gotta give them a plug. Great parts and great service too. Everything tpis I have ever used was spot on.

 

What no 1/4 mile times yet?

 

I heard alot of bad things about them. Like one time, this guy I know got a bent cam off of them, and when he called and told them about it, they said too bad....Huh, Go figure.

 

Nothing gratifying. Had trans problems, and bigtime tuning issues. Floorguy built me a 700 R4, that replaced a manual. And Im in the process of getting a tune on it with a WBO2, when the weather breaks.

 

One last thing, If I put in a lopey cam, what can I expect as a result, and when do I have to worry about the engine idleing to the point that it loads up the plugs b/c of the cam?

 

I've heard lots of bad things about air foils like how they don't do a damn thing on the dyno or the 1/4 mile. Sounds like snake oil to me and folks are still buying them.

 

Been taking notes on DIY prom, and bought a programmer, Tunercat, and a Innovative WBO2. waiting for the laptop though. Well see if it happens, or if I just wasted money. Feeling real good , since the ASM prom I had was way off. The trans will probably be an improvement though.

 

All out *****. The compromise is the more strain you put on your valve train, the sooner you will have to replace it.

 

One thing good about TPIS is they know how to advertise, and IMO, mislead their customers.

 

ASM, there is another one who is full of it.

 

Don't hold back Brutal, tell us what you really think.

 

Hey Guys, I know this thread is kinda dead, but I was wondering about a second part of a question I posted about a cam.
The response was:
So the next part of my question is what kind of numbers (lift/duration) can I use to still run on pump gas and not put too much wear on the motor. - BTW, I don't know if it matters, but the motor might end up being a brand new, built from the ground up, 383. Thoughts on that are welcome. Thanks. - Mike

 

the cam selection is based on how you'll drive the car.

street or race?
trans?
keeping FI or going carbed? modified FI?

 

Mostly street, a little bit of strip. Trans for now is a T5 (crap) but I want to do a T-56 or another 6 speed if I can find one I like. Staying FI, don't know if it will stay factory. Modified FI??

 

If your looking for an easy answer to a complicated question, I'd say 230ish duration and .500 lift would be a good cam for a mild modded 5 speed car. A 383 could use soemthing a bit larger, all depends on your combo and what you want, I'm sure many would call that a mild cam for even a daily driven 383. Since you plan on using FI, I would try to find someone with a similar engine/ drivetrain combo and see what cam they are running. Ask them if they like it, would they change cams, etc. They could probably help you with tuning as well.