Scrutinize my turbo setup! Don't hold back, I want to know! It's is on my C3.2 BTW.

[Tippy]

Background:

Bought my turbo'd '87 Carrera (has 964 bumpers/skirts, replica speedlines, melted tail, coilovers) from a friend who had originally bought it from Miami. The engine only has the turbo setup, stock cams, and 930 pistons and barrels running 1-1.2 (creeps) bar of boost. Exhaust is 3.5"s to 4" by the end of tip. Has full bay IC and either 380cc or 550cc injectors.

Turbo system did not have a BOV until I put my old HKS (1 1/2") on it. Shaft play is really bad and obviously the seals leak really bad causing a lot of smoke under boost.

It has made (I have the dyno sheet) 427whp with the G-50. I was told it has made as high as 447 to the wheels but do not have that dyno sheet to backup data.

Here is how the turbo responds in normal WOT shifting through gears:

1. 1st gear - no/very little boost until 5500RPM, then the sledgehammer effect of full boost
2. 2nd gear - no/very little boost until 4500RPM, then the sledgehammer effect of full boost
3. 3rd gear - slight delay before full boost after shifting from 2nd
4. 4th gear - full boost right after shifting from 3rd.

Anyways, here is the questions I have:

1. Is my headers good/bad?
2. Would dividing the turbo flange/divided turbine scroll be worth it? (read last night the entire fight about this one but still inconclusive and got excited when I saw the WG system is divided!)
3. WG system - is it too long?
4. What size is my turbo? (Friend I bought from says Turbonetics (that's confirmed - has the "T" on housing) T60-1 0.81 A/R. Sound correct?
4. Who made my system? (Friend thinks Protomotive)
5. Why is lag soooo bad?
6. Is the shaft play contributing to so much lag? I would think so?

[930gt-40r]

Personally, I would have the t-4 flang cut off and have a divided t-4 flange fit to it. Then with the divided flange, throw a divided hot housing on the turbo or go for one that does. I don't understand why the boost comes in so late with that tiny exhaust housing on there- maybe the turbo is tired? And the waste get system may be a bit too long- I had the same creeping issue with my old setup and it was due to a long waste gate circut along with improper placement...

[drmatera]

A T4 .81 housing on a stock 3.2 would be very laggy. That turbo looks like it ate a chain link fence, does it smoke or have any shaft play?

[Tippy]

Originally Posted by 930gt-40r

Personally, I would have the t-4 flang cut off and have a divided t-4 flange fit to it. Then with the divided flange, throw a divided hot housing on the turbo or go for one that does. I don't understand why the boost comes in so late with that tiny exhaust housing on there- maybe the turbo is tired? And the waste get system may be a bit too long- I had the same creeping issue with my old setup and it was due to a long waste gate circut along with improper placement...

You think the housing is too small? It is roughly 2 inches smaller I believe than the compressor. You think the WG circuit is really killing it?

Originally Posted by drmatera

A T4 .81 housing on a stock 3.2 would be very laggy. That turbo looks like it ate a chain link fence, does it smoke or have any shaft play?

The .81 I thought is the reason for the severe lag but 930gt-40r thinks it's too small?!?! Yes, the turbo shaft is very sloppy (it did not have a BOV) and it must have not had a filter for awhile .

[drmatera]

if it was a T3 .81 you would be ok, but that turbo has got to go. If you want quick spool up you will need a smaller exhaust side. Maybe a GT35r or even a GT3076 (may be a bit small for a 3.2). If you don't need a fancy turbo you could try a Master Power 60-1 T3/T4 with a .63 backside

[RarlyL8]

The waste gate circuit appears to exit unter the T4 flange at sharp angles which is not optimal. More importantly, that turbo is a fright pig. You'll give up some power going smaller but the car will be much quicker. For the 930/T3 application I like the K27HFS. Your T4 setup will require some homework to find the right turbo for your needs. The GT35R is a popular size for your power level.

[Tippy]

Originally Posted by drmatera

if it was a T3 .81 you would be ok, but that turbo has got to go. If you want quick spool up you will need a smaller exhaust side. Maybe a GT35r or even a GT3076 (may be a bit small for a 3.2). If you don't need a fancy turbo you could try a Master Power 60-1 T3/T4 with a .63 backside

You think a .63 would kill upper hp? Don't want to lose too much.

Originally Posted by RarlyL8

The waste gate circuit appears to exit unter the T4 flange at sharp angles which is not optimal. More importantly, that turbo is a fright pig. You'll give up some power going smaller but the car will be much quicker. For the 930/T3 application I like the K27HFS. Your T4 setup will require some homework to find the right turbo for your needs. The GT35R is a popular size for your power level.

Hello Brian, thanks for responding.

Fright pig? I don't follow what you mean, please explain. Why does sharp angles cause issue on the WG circuit? Are GT35R's possible to find without being new? Know who may have made these headers? That's one of my bigger questions.

[RarlyL8]

Fright pig = nasty scary looking. As Darin said, it looks like it ate a chain link fence.

Sharp angles interfere with the flow of the exhaust to the waste gate. The flow of air is pointed towards the turbo and will not make a smooth transition into the waste gate pipes once the waste gate opens. This can cause overboost and sluggish or less crisp response of the waste gate.
The headers primaries appear to be a similar design as mine. They should work well for you if the ID is not too large. Do you know what size the pipes are? An ID of >1.5" will contribute to lag in your application.

Your Carrera must be a handful with that engine!

[Tippy]

Originally Posted by RarlyL8

Fright pig = nasty scary looking. As Darin said, it looks like it ate a chain link fence.

Sharp angles interfere with the flow of the exhaust to the waste gate. The flow of air is pointed towards the turbo and will not make a smooth transition into the waste gate pipes once the waste gate opens. This can cause overboost and sluggish or less crisp response of the waste gate.
The headers primaries appear to be a similar design as mine. They should work well for you if the ID is not too large. Do you know what size the pipes are? An ID of >1.5" will contribute to lag in your application.

Your Carrera must be a handful with that engine!

I don't have a dial caliper around so I used a tape measure. I know this is far from accurate but I got about 5.25 inches circumference equalling ~1.67 inches, so I don't know honestly. If it is bigger than 1 5/8", it is just another contribution to the lag.

As far as a handful, yes it is! I trapped @ 124MPH in the quarter and have pulled a new 600RR Honda sportbike on the highway (speed not disclosed , I know I will get crap for this).

With the old Potenza 285's on the rear, I was spinning 4th slightly and 3rd fairly decently. 2nd was useless and 1st just doesn't make enough boost to doing anything.

[drmatera]

I hear alot of guys talk about lots of tire spin in 2nd, 3rd and even 4th gear. Maybe my 315 tires hook like glue because at 420rwtq I have no traction issues at all in 2nd gear on up. Even 1st gets decent traction

[930gt-40r]

Well- I finally got my 4094R on my setup and I have to say that with a 1.06 hot side, my new headers (1 3/4" primaries, 2 1/4 secondaries, fully divided...), and no tune- the car spools 500 rpm faster than my PT-67 with a .81 hot side and B&B triflow headers with 1 5/8" primaries. Why it spools faster I dont know- Im sure that the car can breath much easier now. But a .81 is kinda tiny in the grand scheme of things.

[RarlyL8]

Actually, lag will increase if your primaries are larger than 1.5"ID. You need to get to 500WHP before stepping up to 1.625" primaries.

Yes 124mph in the quarter is pretty stout. I love to do the 0-100mph sprints as it is soooo quick.

Tire spin has a lot to do with suspension settings. Mine suck so the 315's can be blown away up to 60mph. Also depends on when Thor's hammer hits. The more lag you have the harder the hit, the harder the hit the easier to bust loose the balognas.

[lite75]

looks like the protomotive header I have except for the wastegate pipe, what's the size of the primary pipes? Plus one on the GT35R, bolt on upgrade from what you have.

[930gt-40r]

Well on my application the 1.75" primaries helped out big time, but that is with a whole host of other modifications as well. The 1.625 primaries were striaght choking my motor up- but thats due to increased displacement, porting, and cams. I am not lying when I say that the car spools like 5-600 rpm faster on the same tune.

[drmatera]

Originally Posted by 930gt-40r

Well on my application the 1.75" primaries helped out big time, but that is with a whole host of other modifications as well. The 1.625 primaries were striaght choking my motor up- but thats due to increased displacement, porting, and cams. I am not lying when I say that the car spools like 5-600 rpm faster on the same tune.

I'm curious, how did you determine the 1.625 primaries were choking the motor? What were the signs?

[Tippy]

Originally Posted by drmatera

I hear alot of guys talk about lots of tire spin in 2nd, 3rd and even 4th gear. Maybe my 315 tires hook like glue because at 420rwtq I have no traction issues at all in 2nd gear on up. Even 1st gets decent traction

Trust me, the car is dangerous in cold weather. I nearly lost it a few times. The boost is all on none. One second a stock Honda Civic is pulling me in 1st gear, then the boost kicks in, in 2nd and it violently just slams you back. The last time it spun in 4th (multiple times) is when I first bought the car and was showing my family. That was with 2 people and 100 degree weather.... Since the 275mm PS2's, the traction got a little better.

Originally Posted by 930gt-40r

Well- I finally got my 4094R on my setup and I have to say that with a 1.06 hot side, my new headers (1 3/4" primaries, 2 1/4 secondaries, fully divided...), and no tune- the car spools 500 rpm faster than my PT-67 with a .81 hot side and B&B triflow headers with 1 5/8" primaries. Why it spools faster I dont know- Im sure that the car can breath much easier now. But a .81 is kinda tiny in the grand scheme of things.

Interesting.

Originally Posted by RarlyL8

Actually, lag will increase if your primaries are larger than 1.5"ID. You need to get to 500WHP before stepping up to 1.625" primaries.

Yes 124mph in the quarter is pretty stout. I love to do the 0-100mph sprints as it is soooo quick.

Tire spin has a lot to do with suspension settings. Mine suck so the 315's can be blown away up to 60mph. Also depends on when Thor's hammer hits. The more lag you have the harder the hit, the harder the hit the easier to bust loose the balognas.

Same here with the tires being blown off but my 0-60 is terrible. 60-100 would be a better run for my laggy setup.

Originally Posted by lite75

looks like the protomotive header I have except for the wastegate pipe, what's the size of the primary pipes? Plus one on the GT35R, bolt on upgrade from what you have.

<> Need to find a GT35R it sounds like.

Originally Posted by 930gt-40r

Well on my application the 1.75" primaries helped out big time, but that is with a whole host of other modifications as well. The 1.625 primaries were striaght choking my motor up- but thats due to increased displacement, porting, and cams. I am not lying when I say that the car spools like 5-600 rpm faster on the same tune.

Cool!

[Tippy]

I might add that I used to shift at 7200-7500 RPM (Rev limiter is 7500 RPM).

The car feels like it will never stop pulling!

Once I opened the cases and saw the stock rod bolts (not 100% on this one), I felt very lucky from what I read from you guys I didn't turn the engine into connecting rod blender!

I think I will stick to about 6500 RPM tops after the rebuild. The HP peaked somewhere around there according to the dyno sheet.

[EmptyGarage]

I've been reading with interest, especially when the discussion turned to breaking loose the rear end. I've got 284/40/17's on rear a sheet that says my car makes 500 ft/lbs @4200 rpms up and 420 ft/lbs @ 2500 rpm's. Whole list of mods, EFI etc etc. including aa professional designed chassis tuning and balance

I can bust loose in 1st but that's all, I've been concerned as the car is new to me and my first 930..first Porsche, and I've been thinking I've been had! The car pins you in your seat and I can't even track the boost let alone see my speed , I just try to watch road and rpms, but no spinning rearend. I'm glad to hear that not all cars are spinning tops, mine not!

Knock on wood!

[Tippy]

Originally Posted by EmptyGarage

I've been reading with interest, especially when the discussion turned to breaking loose the rear end. I've got 284/40/17's on rear a sheet that says my car makes 500 ft/lbs @4200 rpms up and 420 ft/lbs @ 2500 rpm's. Whole list of mods, EFI etc etc. including aa professional designed chassis tuning and balance

I can bust loose in 1st but that's all, I've been concerned as the car is new to me and my first 930..first Porsche, and I've been thinking I've been had! The car pins you in your seat and I can't even track the boost let alone see my speed , I just try to watch road and rpms, but no spinning rearend. I'm glad to hear that not all cars are spinning tops, mine not!

Knock on wood!

The fact yours makes so much low-end torque tells me your system is very linear and responsive. Mine is not responsive and very on/off like a bottle rocket probably explaining the traction problem I have.

I can't even break the tires loose in the rain in 1st - no boost 'til 5500!

But, as I said, the spinning in 4th was on the old Potenza 285's. The 275 PS2's helped a little but 3rd will still break loose usually every time.

[930gt-40r]

Originally Posted by drmatera

I'm curious, how did you determine the 1.625 primaries were choking the motor? What were the signs?

Because when I went to the 1 3/4" primaries/ 2 1/4" secondaries and I gained spool and top end just by bolting them on with my old turbo. The header design was roughly the same as my old headers, just bigger tubes and diffrent wastegate placement. Now with my 4094R- it has a divided hot housing (1.06 a/r) and it spools even faster than my PT-67 (.81) which is considerably smaller. I get 15 Psi out of the 40R+ new headers at 3400 rpm where before I couldnt see even 7 psi on the old setup at that rpm. The whole reason I went to big primaries/secondaries was because I wanted to push out 700 horse on race gas. On pump gas- Ive seen simaler setups make about 550 on reasonable boost