87fbodyy

im puttin a tpi setup on my 355. what can i do to get it to breath up to like 6k?

-justin

watajob

iTrader: (29)

A really good port job on the plenum and some type of siamesed runners. Although the peanut cam and mediocre heads aren't going to help.

Phenom-1

Vortec heads or L98 heads with 64 or 58 cc, Comp Xtreme energy cam, lifters, valve springs, chain set with a range from 1600-5800 rpm for $335, also 1.6 roller rockers for $210.

ibmtech

iTrader: (1)

Don't forget if you start to change the geometrics of the engine and putting 1.6 rockers in to additionally check the pushrod height and ensure you also change them as necessary

vetteoz

iTrader: (13)

Might rev to 6K but won't make power up there.Even big tube aftermarket TPIintakes flatline over 5500

Checkout the Hp graphs in link below to see where they level off
http://xtremecarzone.com.au/index.php?showtopic=386

TPI can be made to breath if you want to do some work
https://www.thirdgen.org/forums/tpi/...owing-tpi.html

or buy a FIRST TPI intake
http://www.firstfuelinjection.com/products.htm#P1
https://www.thirdgen.org/forums/alte...n-runners.html

vetteoz

iTrader: (13)

If you are installing a new cam then you get one with the valve lift you want on the cam and then you don't need 1.6 rockers
1.6 rockers are only for those that want higher lift but don't want to open their motor up for a cam swap

Johnny Blaze

iTrader: (15)

Pull the TPI intake and put a Stealth Ram, Super Ram, or Mini ram, and the appropriate cam and other parts as suggested.

cuisinartvette

With Johnny and Oz.

You want an intake that will make power up there toss the TPI aside.
It will never make power up there period. Revving up that high doesnt mean its doing anything.

Whats up with 6k is it a requirement for?

Orr89RocZ

iTrader: (20)

Fully ported aftermarket base with slp runners siamesed about half way will support 6k rpms

Dyno Don

iTrader: (7)

I have to challenge that statement

Johnny Blaze

iTrader: (15)

Wow, thats almost legible.

ibmtech

iTrader: (1)

In general with the design of the TPI it takes alot of porting to get it so it doesn't fall flat on its face.. The length of the runners alot it to be a torque monster. Going with a newest intake like was previously stated, Stealth Ram, Mini Ram, etc.. would be the easiest way to get more power

watajob

iTrader: (29)

.

vetteoz

iTrader: (13)

I did post a link above to your fine efforts

ASE doc

I shift my long tube TPI 355 at 6,800. It does have a slight plateau at 6,500 but it's very slight and it runs faster when I hold it to 6,800. The key is a perfectly matched intake tract from the throttle body to the valve, a well tuned exhaust and the right valve duration and lift. Most people think that the ZZX(240/240 @ .050 560/560) that I run is too much for a TPI motor on the street but in fact it was designed for a high revving TPI and it drives very well. The ZZX is a big part of the reason my motor makes power past 6,000 rpm.

I also built my motor with low tension 1/16 rings and lightweight pistons. I run a vacuum pump to keep the crankcase in negative pressure. This overcomes the small block Chevy's tendency to develop excess crankcase pressure at high revs. This pressure and the resulting dilution of the combustion charge is much of why most street small blocks fall off at 6K.

I get alot of doubters here, since my build and results seem to fly in the face of claims that TPI will not support high rev power. I admit readily that TPI is not the best for this type of use. I built this motor just because I wanted to see how far I could take true long runner TPI and the results have been satisfying. My next motor will probably run a custom sheet metal intake.

I plan on running the car at Woodburn Drags next month for NAPA's track day. I don't expect much in the way of ET with my road racing suspension setup and tires. But I do expect to see some high trap speeds.

ASE doc

I may have been mis-stating my shift points. I forget that my factory Tach reads about 300 rpm high. Therefore, 6,800 is actually 6,500.

I almost didn't get to run at NAPA days. Checked my tires one day and found the right front bald. Too much fun in the corners this summer. Tech will let alot slip by but not bald tires. Getting new tires and alignment checked tomorrow. I'll be ready for the 21st.

To test the claims of long tube TPI dropping off above 5,500, I will make a run or two shifting at 5,700. The rest of the runs will be made shifting at 6,500 where I generally shift at full throttle. I can guarantee that the runs shifting at 6,500 will show consistently higher trap speeds.

ninetyone

iTrader: (2)

We dont need to make power up that high. Our cars can be further down the road at 4k vs another vehicle revving to 6k.

Orr89RocZ

iTrader: (20)

How so? If tpi only can make 350 hp at 4500 and flatline, how do you expect it to beat a car with 375 hp at 5500 that is geared right with say a stealth ram. Been there done that. Stock L98 with stock tpi vs hsr, same stall and gearing and tune, stealth ram out acceled in all categories from 60 ft to 330 to 1/8 mile to 1/4 mile. Tq was less but hp more at another 1000 rpms of power range

Street Lethal

iTrader: (16)

Stop light to stop light I will agree. On the highway though, not a chance...

Orr89RocZ

iTrader: (20)

I dont buy the short distance stuff either. Short times at track still favored more average power and flatter torque curve of the shorter runner intakes on most setups i have seen including my own hsr L98 vs bolt on tpi l98 formula

ASE doc

Power is power. It's all torque, whether it's the peaky torque curve of a stock TPI or the wide flat torque curve of a Miniram. The difference is that an engine that makes a wide flat torque curve, with more top end power, makes more average torque than the stock TPI with its short peaky torque curve. What makes a faster car is more average torque.

My max effort TPI is not the ideal setup for high rev power nor does it produce the ideal long flat torque curve. What it has done is expanded the torque curve of the long tube TPI by a considerable amount, making a great deal more average torque than the stock 350 TPI. Enough to make the IROC a really fast car. The greatest benefit of making power past 6,000 is upshifting right into the engine's power band at 4,000rpm.

jmd

iTrader: (4)

Use a 4bbl manifold with injector rails. Machine and bolt a TPI plenum with throttle body up front like TPI. TIG the rails to that to look like TPI. Fix any vaccuum leaks. Enjoy.

88I-ROC

Is the event open to the public? I live in the area, and I might come to check it out.

ASE doc

I think it's NAPA only. They rent the track for the day. If you PM me, I'll give you my phone number. You can call me if you're close by and I'll get you in as my guest. I assume you know where the track is. It's about 1 mile from my house.

DBLTKE

iTrader: (1)

Wow, you guys live pretty dang close to me. Although you should come up to PIR before the end of the season, I work for the drag strip as a tech inspector.

88I-ROC

I was just there couple weeks ago and talked to you. I intend to come next weekend as well...

Johnny Blaze

iTrader: (15)

What's so magical about 6k?

DBLTKE

iTrader: (1)

Oh, lol didn't realize that was you. Just keep in mind that we're closed this weekend. But will be open the weekend after.

ASE doc

Nothing really. It's just a question of extending the TPI's torque curve to make power at higher RPMs. 6K comes up because it's generally accepted that TPIs fall off at 4,500.

TallTim

iTrader: (2)

Just was on the dyno this summer for kicks and I don't think it revved over 4200. Made about 210 WHP but then flatlined just like the dyno guy predicted. Maybe need a bit of a tuneup.

88I-ROC

Its not just because of the TPI, it's mostly because of the cam and heads. My friend has the same setup as yours, but replaced the cam and heads, now he have no problem reving to 6K rpm even with the stock TPI.

vetteoz

iTrader: (13)

Has it been on a dyno ?
Revving it to 6K is one thing , still making power up there with a TPI is completely different story
Read the intake comparison link in post # 4

88I-ROC

In the country where is at, there is no shop with a professional dyno that we know of, but I was telling him the same thing, then he told me he can still feel the car pulls past 5500.

ASE doc

I have not had my car on a dyno. However, I have driven 100s of peformance vehicles from a 68 396SS to an 07 Chrysler SRT Hemi to an 02 Vette and everything in between. I have a pretty good idea of what it feels like when an engine passes it's usable torque curve. A good test of the TPI is the 2/3 upshift on the 700R4. Of course you need a trans that is built to hold 2nd gear above 5,500. The stock unit will not. The stock TPI falls off severely at 4,500 and will not pull above 5,000. You can hold the throttle down and force the motor past this point but it is obviously out of breath. In contrast, a properly built small block chevy with an Edelbrock Performer RPM will pull strong right to 6,200. The difference is obvious. You don't need a dyno to tell you this.

My max effort TPI pulls to 6,200 with every bit of the torque that any of the Performer RPMs and Holley 750 combos Ive ever driven.

I'm not a dumb kid. I am a master mechanic with 40 years of building engines behind me. I'm not gonna sit and hold my engine past it's usable torque curve and pretend it's still making power. If my engine didn't make solid power to 6,500, I wouldn't shift at 6,500.
I've said this many times. The TPI, and this includes the First, is not the ideal intake for high rev power. Neither is the stock LS1 intake. They were not designed for this. However, in a properly matched combination, starting with the rotating assembly and ending with the intake air tube and exhaust, I have proven, atleast to myself and several other professionals in my area, that a long tube TPI can make usable torque past 6,000rpm. This next friday I will demonstrate this to many more local professionals.

In fact, since I mentioned the Performer RPM, the torque curve of my extreme TPI is very similar to that of a small block that I recently drove equipped with the Edelbrock Performer RPM power package(heads, cam, intake). In fact I'm thinking they would run just about side by side.

ASE doc

You know. As I step down from my soap box, I have to admit that building this TPI the way I did was very expensive and time consuming. Alot of time porting and testing and the cost of high flow parts that I then spent hours porting and checking. All to get the same output as an engine built for a fraction of the cost. For about what I spent on intake pieces, I could have bought a Mini Ram and made more power. For less than I spent(though it wasn't yet available when I built this engine) I could have bought a stealth ram and made more power.

The moral of the story is that I built this motor based on an idea and I did not get the best bang for my buck. Unless you're really stuck on TPI, there are atleast two readily available options that will out perform it, no matter how many hours you spend porting.

Dyno Don and the cali gang have done amazing things using the SLP siamezed runners. But, and I hope my freinds don't take offense to this, what they are creating is no longer long tube TPI and can't really be compared to it. 1989GTATransAm built a large tube long runner TPI that, while I haven't seen any recent test results, I believe still holds promise.

My point is, using commercially available pieces and applying considerable experience, I have taken my TPI engine as far as it can go. While I am pleased with the results I have achieved, I am already planning my next engine and while it will of course be fuel injected and use a tuned runner intake design, it will not be TPI.

Dyno Don

iTrader: (7)

Yes, it has been on the dyno and no it does not make power at 6500, it starts to drop off at 6200.

heat seeker

iTrader: (5)

It looks like it stops making more power at around 5k, am I seeing things correctly?

neagan

iTrader: (7)

Chipping in from California.

I, like many of my bretheren 3rd Gen owners have been faced with the ongoing political black-hole that's been trying to swallow (get rid of) automotive vehicles in our age group. It seems that every time we turn around the state has found a new way to fail our car's emissions. For awhile there, with the paranoia brought on by a couple car movies, police departments in cities were siezing cars that were no longer 'factory' in appearance under the hood, by naive guesswork at times.

I know I spent a crazy excess amount of money on my TPI system, and the other general improvements that go with it, all with the goal of keeping the State of California off my back. 5-7 years ago, there wasn't much posted about Dyno results, so people like me who are good at swapping in parts, but never knew how to test sensors had a steep learning curve until some of you more engineering and actually automotive trained guys started posting actual provable results.

Thank God for people like Dyno Don who finally made a decent quality header that fit and saved us from the crap that was out there. Then there's all the people that were willing to try different heads with the cams and report the emissions.

For me, it's not just about having an IROC that can have a 6500 rpm power band, but that my engine will rev to it much quicker, smooooother, is repeatable under load, and will pass emissions sniff test and a visual inspection. You guys are my honest to God hero's. Nitro-Nicky

1989GTATransAm

iTrader: (3)

I think you guys are looking for this dyno pull.

ASE doc

That's the siamesed SLP that you are still running now, isn't it? The beauty of this engine is 420HP at the wheels and it looks close enough to stock to slip under the radar.

Dyno Don's dyno pull above does not drop off at 5,000. It flattens out but continues to make good power to 6,200.

1989GTATransAm

iTrader: (3)

You are right that is the First/SLP runner setup. I am currently running the first version of the long tube runners. I don't have a dyno graph of it but it made similar power as in the above graph but the peak HP was around 6200 and had it had a dual peak. The peak torque was 300 rpm or so lower than the above graph.

That is the reason for version 2 of the long runner intake manifold which is waiting to be installed and tested. It has somewhat shorter runners, a bigger plenum and a little more CSA in the base. Hopefully it will exceed the above graph. Bottom line is with enough CSA you can make power with a long tube runner.

ASE doc

Yes. I just revisited the "Long Tube Runner TPI" project thread and saw photos of the second version. Very good stuff.

PhoenixFirebird

iTrader: (2)

Food for thought: what about a siamesed base? I have one myself, although I'm not at the point of making good power with it (yet). I've heard Vette guys have had good success siamesing the base aswell as the runners. What are your thoughts?

Street Lethal

iTrader: (16)

I have a fully siamesed setup on my turbo 305, works very well, just pay attention to your off idle tuning and stall speed range...

PhoenixFirebird

iTrader: (2)

What sort of rpm range are you shifting at with a fully siamesed setup? I would imagine around 6k due to the shifted powerband, right?

Street Lethal

iTrader: (16)

Yes, at 6000-RPM. The cam has more in it, and the turbo essentially wants to help rev the engine to the moon, but the valvetrain isn't that strong just yet so I cap it at 6000-RPM...

mhou91z

It’s very important to pull hard up to 6K, especially if you’re running a 700R4, reason being is because the broad gear change from first to second is massive in the 700R4. So if you have two identical mildly tuned cars and one is able to shift at 6200rpm and the other at 5500rpm the lower shifting rpm will be much lower in the power band (say 3000) when it at the bottom of second or third gear, where as the higher shifting RPM will start at around 4000RPM at second and already have a large advantage. So the higher shifting car will be ahead all the way through the gears cause it doesn’t have to climb out of the lower RPM rut after each gear change.

ASE doc

This is right. Having the motor make power past 6,000 makes the upshifts much more efficient. I however just learned the downside of that. The 700R4's 3-4 clutch pack does not handle high horsepower, high rev upshifts very well. After 13 years of life behind this motor, and especially the last few years since I installed the evacuation system and really got it to make power above 6,000, 3rd gear finally left me at Woodburn Dragstrip last Friday. I had noticed that the 2-3 upshift was starting to have a delay. I would hit 3rd at 6,200 and hit the rev limiter at 6,900 for as long as 1 second before 3rd engaged but it wasn't every time. Now I know what was causing it.

I'll be tearing down the trans in the next few weeks and I've started a thread on how to beef up my 700R4 in the transmission drivetrain forum. I'll post what I find on the tear down and what modifications I make to prevent subsequent failures. Through my research, I have found that the 3-4 clutch pack is the weak link in the 700R4. One cure I have found is the Smart Tech input drum from Sonnax. I plan on using this part.

neagan

iTrader: (7)

Sad to hear that. My Sun Gear was actually completly sheared off in two pieces when I did my tear down; don't know how it was still shifting-

That seems to be the problem in several major areas with our cars and is why I finally parked mine and started a complete performance upgrade from front to back. Of course now that I'm 3/4 of the way through, I've figured out 'new and improved ideas' and want to go back to the beginning and start over again, but I noticed my wife has been eying a box of bullets every time I bring that particular subject up now......

The performance Trans shops certainly didn't have access to the Smart Tech input drum from Sonnax when I had my hefty build-up done for my 700r4. That's a pricey part! All the best clutch packs in the world won't help if they're flexing around though, so that makes sense. I thought that Sonnax only made those for the heavy duty next generation transmissions though, not for the lowly 700's. Is this a new release product>?

ASE doc

I don't know when they started making the Smart Tech for the 700. I just found it on PATC's website. I definitely recommend atleast visiting their site before doing any trans upgrades. Whether you buy from them or not, they are doing tings with these units that no one else even comes close to. Their Raptor level 5 is rated at 1000+HP/1000ftlbs.