My dad is building a 76 Camaro, and is building a 400 small block, he was originally going to go carbed but then he bought a TPI set up off a 85 Corvette. He read that the tpi intake barely flows enough for a 350. Is there anything he can do other than buy a special intake from summit?

 

he can port the whole thing out.runners,base,top piece.if he wants to save money ,that the cheap way

 

There are high flow runners available. Although a variety of places have them, the runners from Arizona Speed and Marine and TPIS (which, reportedly, TPIS buys from ASM and then jacks up the price) seem to be the hot set-up. IIRC they go for $475. Add another $175 (IIRC) to that if you want them polished.

 

I am running a built 406 with a TPI out of a 1988 F-Body the only changes to the TPI was to convert it to Speed Density, port the plenum and manifold.
I am running 10.8.1 compression with Trick-Flow Gen1 heads (ported by me)
A Chet Herbert roller cam with 222/234 @.50 .499/.502 lift.
and a T56 6-speed.
I programed the PROM for 32 LB injectors and after I built the motor I had a bad 'stumble' during low-speed acceleration using the stock "350" injectors I then installed 30lb/ft Accel Injectors and it cleared it right up.
The car is AWESOME, unreal torque and horsepower... I love my 406!
Go for it, as you can see other than the injectors and porting my TPI is stock and works GREAT on the 400!

 

Another good option is to use a set of SLP runners. Siamese the port exits at the plenum and siamese down the runners at least 4-5 inches. Also you must port the intake since it is a major bottle neck in the system.

www.geocities.com/dzperf

 

I would disagree...I had the tpi on my 406 and it was choking the crap out of it. I had ported plenum,intake, slp runners and a 58mm tb. It would flat line at 4500 rpms. And I even have 30lb injectors. I switched to Stealthram. Made a huge difference. I also switched to SD.

 

Most people build for hp with no regard to what rpm range the eng will operate. Decided on your rpm range then build for it. If you want moster torq 400 then a tpi would work for less then 4500 rpm's with maybe a hot cam and 1.5 rockers, the 1.5 rockers decreases the duration by about 2 degrees. Many recipes out there for eng's, just choose one that fits your wants/needs.

 

I dont agree with the first statement. If your gonna build a motor and you havent thought out the process as to what you want then either your an idiot or your mechanic is an idiot for not asking what you expect from the buildup. Less than 4500rpms....thats what the tpi will do on the 400. You cant even race with 4500 rpms. Most people shift at a minimum 5000rpms. You must decide what you will do with the car. Is it a daily driver? DO you want better gas mileage? Are you gonna race full time or part time? Carb is best for racing, fuel injection is better for gas mileage. Its a matter of choice. I kept my fuel injection because I wanted both a daily driver and good gas mileage. Now I dont really care about either. My next motor is ready to drop in and I am undecided about either carb or FI.

 

It is going to be a daily driver, im pretty sure he is thinking about purchasing a new intake from summit. Could he get an LT1 intake to work?

 

An LT1 comes from a 350 block so yes it will fit. I put a 305 intake on the 400 originally.

 

....The HOTCAM makes its power in the upper RPM's. Bad choice for a TPI on a big inch motor.

You can argue the merits of the TPI/ high cube small block all day, but the bottom line is YES it will work, but NO it will not be ideal.

Everyone forgets that the TPI is good for torque, due to the demands of a 350. The torque is created by the high airspeed moving through the small runners. This same benefit is what hinders its top end. On a 406, the line between beneficial torque producing airspeeds, and restricted airflow happens much lower in the RPM due to the higher demands of more cubes. (the 406 uses more air at the same rpm, therefore it gets choked quicker). The torque that would be gained by using a TPI over say a Mini-Ram would be almost pointless when you consider the HUGE power gain of the the MR's top end ability.

The LT1 intake will bolt up, but has no provision for a distributor or a thermostat housing. Modifications will be necessary. Check out www.lt1intake.com

...it would work pretty well though!

 

Thanks for clarifying..

 

aerosmith
I reccommend that you go with:
a good carb, and a good intake manifold.

 

I would not call them idiots, I will say they are blinded by peak numbers. Nice to brag your eng's makes 500 hp but if it is a 327 that spins to 8000 rpm's that won't be much fun to drive in a heavy f-body on a daily basis. The intended use of the car will dictate the operating rpm's. If you like to race every weekend then the TPI might not be for you but if you are building a daily driver, with some porting it would be a pretty good fit and cheap.

BTW IMHO the hot cam is not the wild of a cam at all and works pretty well with a TPI, I am running one right now with a stock TPI. With the 1.5 rockers the duration is only about 216/226. Had an LT1 intake on it and it pulled to hard to about 5200-5500 rpm's but did not have the low end torq it does now. With some porting I can see it being a pretty good match, maybe not optimal but few combs are 100% matched perfectly.

 

I have been very pleased with my modified TPI on my 406. It is a blast to drive on the street, and still gets into the 12s at the track. A better than stock base will help. I went with the Edelbrock base, SLP runners, Holley 58mm TB and ported the heck out of plenum and runners.

I have to say, I built the motor for mid-low 12s and the intake IS holding me back, but since I do most of my driving on the street, it is a good thing. I still get 15.7mph in town on a 406 I cant keep my foot out of. More on the highway.

 

he has a carb intake and eldebrock card that he was originally going to go with but he wanted to go fuel injected and i think he still wants to stick with fuel injected.

 

Who's bragging about 500hp? I dont have a 327 that spins to 8000rpm. If you were referring to me then you should read my sig. Its a 406. What you said in your first paragraph has already been said. Its a matter of what you will be doing with the car that determines what combo you should have.

 

Thats not a problem. There are some options available besides tpi. You can find charts here online comparing different intakes etc. to determine what you want.

 

Cool. It held me back too even tho it was fully ported and matched to plenum and runnners etc. I was not happy with it but it seems you are.

 

Was not reffering anyone specific, just using an example of a 500 hp eng that most would not want in their car. No need to get your panties in a bunch.

 

You could only know I was wearing panties if you peeked! No offense taken here. Its hard to read into what someone is trying to say sometimes.

 

Hi, all. I am building a 406 with tpi too. My goals are somwhat different that what you guys are looking for though. I am building a rock crawler, and am looking for good torque at idle and just off idle. I am running a very mild 406.
small hydrolic cam 208/218 .476 .499 112lc
mostly stock heads,
and 1 5/8 headers and single 3" exhaust
This motor wont really ever need to rev past 4000-4500rpm, so I am hoping a stock mildly ported tpi will be a good choice for me.

 

that should be fine for what you need...

 

Glad to see you got a sense of humor, we may have a differ of opinion on set ups but we can all laugh together.

 

I think the TPI is a great choice. I've heard LT1 intakes often have idle/off idle bogging issues. That's not a big deal for us straightliners, but for a rockcrawler, that would be pretty bad!