TGP manifold question

[ericjon262]

the TGP's are too small, the sealing area gets reduced drastically when you try to port them to a 3500 spec port. I'm going the header route.

[Guest]

If you port them to the size of the gen 2 gasket, then there is still plenty of meat left, and the amount of header that protrudes at the head is minimal. I know because I saw them with my buddies setup he did. IMO not worth building a whole set of headers over. Especially not with the power that you are going to be making. They might rob you 10 hp or so. Not worth spending time and money building headers for only 10 hp.

[ericjon262]

gen 3 ports are larger and a different shape then gen 2.

[Guest]

Yes I know, but when ported, the amount of material from the exhaust manifold that protrudes into the flow of the exhaust is very small its not worth any concern with the amount of power you will be making with your setup. We had a gen 3 exhaust gasket laying around from a bad longblock and compared it to the ported turbo log. it only hung out a small bit down in the bottom of the port at the corners. I just wish now I had taken pics to show you. But like I said it was minimal.

[ericjon262]

Yes I know, but when ported, the amount of material from the exhaust manifold that protrudes into the flow of the exhaust is very small its not worth any concern with the amount of power you will be making with your setup. We had a gen 3 exhaust gasket laying around from a bad longblock and compared it to the ported turbo log. it only hung out a small bit down in the bottom of the port at the corners. I just wish now I had taken pics to show you. But like I said it was minimal.

no need to show me pics, I've seen it with my own two eyes, I'm not satisfied with the available sealing surface on the ported manifold, nor the fact that they just won't flow enough for the 3500. I understand that turbo apps use smaller primaries, and logs, but the TGP's are too small. they were designed around a 3.1, with crappy heads, not a 3.5 with great heads. my car has custom pistons, pro ported intake, and a meaty cam. the TGP's are going to choke it down. if you want them, they will be in the mall when I get the engine back out.

[Guest]

no need to show me pics, I've seen it with my own two eyes, I'm not satisfied with the available sealing surface on the ported manifold, nor the fact that they just won't flow enough for the 3500. I understand that turbo apps use smaller primaries, and logs, but the TGP's are too small. they were designed around a 3.1, with crappy heads, not a 3.5 with great heads. my car has custom pistons, pro ported intake, and a meaty cam. the TGP's are going to choke it down. if you want them, they will be in the mall when I get the engine back out.

You have seen a set of ported gen 2's next to a gen 3 exh gasket? I am guessing online somewhere since yours aren't ported? Not flow enough for a 3500? How much power are you looking to make? They can flow enough to make 400 hp. Your goal is more than that? FYI, the 3.1 heads aren't crappy. They just don't flow as well as the gen3 thats a given. The iron heads are crappy.

What kind of pistons did you end up getting? Is it the same ones you said you bought but aren't in the engine yet? Or is the motor in your car now have custom pistons as well? The Tgp's manifolds will choke it down, but not at 300-400 hp.

I guess I was just looking forward to seeing this car done sooner than later. All this stuff you are doing will take another year. I am not trying to change your mind or anything, I just don't know what your goals are hp wise for this thing.

[TGP37]

What is the HP limit on a Fiero before the frame starts to twist/bend or stretch?

At some point I believe the track you race at will want a roll cage when you reach a certain range of power. With your build, you might need one, or keep it just under 500 HP.

My goal was low 400's and I am happy with that for a car that is almost twice as heavy as your Fiero.

[pocket-rocket]

At some point I believe the track you race at will want a roll cage when you reach a certain range of power. With your build, you might need one, or keep it just under 500 HP.

The drag strip closest to me has no requirements for 13 sec.+

12.999 and faster requires a helmet.

No idea when cages become mandatory.

Sent from my HTC One X using Tapatalk 2

[TGP37]

The drag strip closest to me has no requirements for 13 sec.+

12.999 and faster requires a helmet.

No idea when cages become mandatory.

Sent from my HTC One X using Tapatalk 2

I remember PontiacJeff from EP told me his GP required a cage at 500+ whp. But that is Florida.

As for turbo primary size, I just learned the best primary size for turbo is the same size of the exhaust port. Then add 1 step up 1/8" in diameter part way through to hold back reversion and reduce back pressure at higher rpms. The step up would be best placed at the same distance from the other ports, after the bend.

[ericjon262]

You have seen a set of ported gen 2's next to a gen 3 exh gasket? I am guessing online somewhere since yours aren't ported? Not flow enough for a 3500? How much power are you looking to make? They can flow enough to make 400 hp. Your goal is more than that? FYI, the 3.1 heads aren't crappy. They just don't flow as well as the gen3 thats a given. The iron heads are crappy.

What kind of pistons did you end up getting? Is it the same ones you said you bought but aren't in the engine yet? Or is the motor in your car now have custom pistons as well? The Tgp's manifolds will choke it down, but not at 300-400 hp.

I guess I was just looking forward to seeing this car done sooner than later. All this stuff you are doing will take another year. I am not trying to change your mind or anything, I just don't know what your goals are hp wise for this thing.

I port matched my TGP manifolds to the 3500 head. there just isn't enough meat on the manifold to support a proper seal to the head left, and that is my biggest beef with the TGP manifolds. it won't take long to make a set of headers once I have the engine back out, and they will outperform the TGP manifolds, and they will seal to the head.

I don't really have a defined goal right now, at first, it was 450 RWHP, but I think I may be able to go well past that with the bigger cam/ported intake set that I just got, along with doing it more reliably, with the forged pistons and rods that will be here in my hands in a few hours...

@ TGP37

there isn't a track I race at right now, this car will be my DD. I've never heard of people having problems with fiero frames twisting or stretching, and you are right, I may end up needing a cage, if that happens, I'll dial back the boost for track days!

[Daguse5853Z]

I got rid of my TGP exhaust manifolds because of the small area available to seal them to 3500 heads and decided I didn't want to risk them leaking and decided to build my own manifolds. I have 2 3X00 crossovers that im stealing the flex joints out of to isolate the turbo better and have some room for thermal expansion. Where do you guys get parts for building your manifolds? I have the flanges already but i'm not a big fan of using thin walled tubing for my manifolds. I want to build a log manifold but I havent heard anything back from pm's sent to people asking where they picked up parts.

[3400-95-Modified]

If you want it to hold heat then build it with cast iron pipe... Seems a bit overkill to me. Standard wall exhaust tubing will work fine and is very common on turbo headers so I don't see the issue.

[ga2001532]

What if some one would just get a 3500 flange. Get two threaded Tee one elbow. Couple threaded striaght pipe. Screw the log together and weld it to the flange. Should be exhuast leak proof with threaded connections. What do you guys think if you understand my limited details

[ericjon262]

I got rid of my TGP exhaust manifolds because of the small area available to seal them to 3500 heads and decided I didn't want to risk them leaking and decided to build my own manifolds. I have 2 3X00 crossovers that im stealing the flex joints out of to isolate the turbo better and have some room for thermal expansion. Where do you guys get parts for building your manifolds? I have the flanges already but i'm not a big fan of using thin walled tubing for my manifolds. I want to build a log manifold but I havent heard anything back from pm's sent to people asking where they picked up parts.

I am going to get my stuff from cone engineering.

http://www.coneeng.com/exhaust_system_kits.html

they have nice collectors, and they are cheap too. my hotside will be 16 ga mild steel, and a 3-1 instead of a log (my setup will be twin scroll)

[pocket-rocket]

I've heard good things about cone engineering's parts and materials.

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