Scrapping Twin turbo project - Page 4

MikeD930 · MikeD930's Garage

You painted the headers? Regarding the intercooler I'd leave the rest of the opening alone. Looks like you have T4 flange on your headers. I'm surprised your have 2" compressor outlet. Normally would be 2 1/2" outlet.

Nice headers and IC though!

drmatera · 06-22-2010, 09:08 AM

The headers are thermal coated, not painted. The turbo flange is T3 and the compressor outlet is 2"

drmatera · 06-22-2010, 11:32 AM

and

JFairman · 06-22-2010, 07:29 PM

Hey Darin, looks good.

I see an origonal 3-4" wide steel shroud piece under the screen in the wing. There is another narrower one to the right of where the origonal AC condensor was. They are riveted in origonally and easy to drill out and remove.

With your new full bay intercooler they're blocking some airflow, they gotta go!

drmatera · 06-23-2010, 06:30 AM

hey Jim, Yes I will remove those shields.

911st · 06-23-2010, 07:45 AM

I can not help but think that if the WG could be put right at the turbo it would reduce the header volume for even quicker spool. It could also take one of the two or three changes in direction out of the WG circuit. Also, it would look agressive having the WG peak out under the bumper. Just a thought.

I thought you were thinking of converting your headers to twin scroll?

Looking great!!!

JFairman · 06-23-2010, 07:55 AM

Quote:

Originally Posted by 911st

I can not help but think that if the WG could be put right at the turbo it would reduce the header volume for even quicker spool. It could also take one of the two or three changes in direction out of the WG circuit. Also, it would look agressive having the WG peak out under the bumper. Just a thought.
Looking great!!!

yeah.. but then when he pops a wheelie in that thing it'll get ground off!

911st · 06-23-2010, 08:08 AM

Quote:

Originally Posted by drmatera

BTW, it sits just below the tail "grill". I plan on running a perimeter of foam to seal it to the wing for optimum flow. It doesn't cover the whole grill opening, should I block off the rest so the fan can only pull thru it or is it better to leave the rest open?

Check out what Porsche did with the 993. The IC is schrouded and the intake runs detacated snorkles to the grill.

Thus, there is no preheating of intake air by the IC and all air pulled in by the cooling fan must basically go through the IC.

drmatera · 06-23-2010, 08:40 AM

i had thoughts of doing just that to the wastegate but fitment was an issue. I left enough room on the left side of the intercooler to make a duct to the air filter but i'm afraid rain will get in as well.

911st · 06-23-2010, 08:57 AM

You could add a drain.

Maybe some ideas here but flip it:

Quote:

Originally Posted by jimmcc

Porsche Group B 911 & Porsche World - April 2002

drmatera · 06-23-2010, 09:02 AM

yes, that is what i had in mind. his fan/shroud is the same color as mine

drmatera · 06-27-2010, 10:37 AM

Well the car is done. I dynoed it friday evening, it made more power but spools up much later, About 250-300rpm later. Lag was very noticable while driving the car and showed on the dyno as it was 80 ft lbs down at 3400rpm compared to the K27. It made more power and torque at the peaks but I am NOT happy. I tried tuning away the lag but got nowhere. The car made 382 rwhp (5500rpm) & 412 rwtq (4200rpm) but the power loss down low is like an elephant in the room, even a blind man would know he's there. So I should have stuck with my original plan of the GT35 or I may even check out a GT3076. The intercooler works great and the fabrication work done by KMW Motorsports is very nice, so it looks like i'll be selling this S262.

JFairman · 06-27-2010, 11:04 AM

Thats a drag...

Crazy thought if you have this hardware sitting around

you could always put in nitrous oxide and trigger it with an rpm window switch to blow in nitrous where you're having turbo lag, and turn off the nitrous when turbo boost starts...

yeah I know, overengineered and - definately crazy!

drmatera · 06-27-2010, 12:01 PM

the problem with that is nitrous should only be activated at WOT. The lag is most noticable at medium to high throttle input like taking off from a light or pulling out to pass. Those are the areas I was hoping to improve with this turbo, along with more power potential. I will really have to rethink turbo sizing.

JFairman · 06-27-2010, 12:50 PM

yeah, i was just trying to be humerous in a silly way :-)

Speedy Squirrel · Speedy Squirrel's Garage

I imagine that you used the 740902-4 GT35R part number, didn't you?

911st · 06:43 PM

Found it.

911st · 06-27-2010, 07:09 PM

Looks like the Bullseye 262 which is supposed to be the 362 in a smaller frame.

Looks like a 62mm compressor inducer with a 67.6mm turbine exducer.

Basically about the same as a GT35 (61.4/68mm). (K27-7200 = 55/58mm).

If you do not mind:

Is it a ball bearing turbo?

Where is your boost onset and about where would you hit .8 or 1 bar boost?

What hot housing (T3 or T4) and A/R did you go with?

I can understand it boosting later but it should not be laggy once it is above 4K.

Speedy Squirrel · Speedy Squirrel's Garage

Yeah, that 83mm turbine can't possibly be hurting response. Unbelievable.

Quote:

Originally Posted by 911st

Looks like the Bullseye 262 which is supposed to be the 362 in a smaller frame.

Looks like a 62mm compressor inducer with a 67.6mm turbine exducer.

Basically about the same as a GT35 (61.4/68mm). (K27-7200 = 55/58mm).

If you do not mind:

Is it a ball bearing turbo?

Where is your boost onset and about where would you hit .8 or 1 bar boost?

What hot housing (T3 or T4) and A/R did you go with?

I can understand it boosting later but it should not be laggy once it is above 4K.

drmatera · 06-28-2010, 08:11 AM

Is it a ball bearing turbo? No

Where is your boost onset and about where would you hit .8 or 1 bar boost? In 3rd gear I made a datalog with the old set-up. 2000rpm up to the point it makes full boost. Then did the same with the new set-up. Seems they both start to make boost around 2200rpm but by 2700 rpm the K27 is 2psi ahead. By 3000rpm the k27 is 4psi ahead. Once rpm gets to 3600rpm the S262 really starts to spool quick and catches up with the k27. On the dyno there is a 70ft lb difference at 3200rpm

What hot housing (T3 or T4) and A/R did you go with? T3 .70

Response is the issue. Once we're at 4000rpm the S262 is a monster pulling all the way to, and probably over 6000rpm if I had pulled it that high. Top end is great but i'm not willing to sacrifice that much low end to get it. They do offer a .55 housing.