Where are you making full boost?
Originally Posted by 2000TurboVert
No.. Your right!
Stock manifolds hold heat better than longtubes, which causes a FASTER spool time!
Turbos LOVE heat!!! (Obviously to a certain point!)
Stock manifolds hold heat better than longtubes, which causes a FASTER spool time!
Turbos LOVE heat!!! (Obviously to a certain point!)
I'm trading a buddy of mine my Hooker LT's and my ORY for some stock cast manifolds and a stock catless y pipe, which those had an oval design correct...are those "best" or a tubed 2.5" Y?
Your car is just like mine was. T67, LTs, ORY full spool 4000 - 4500. I wrapped the y too. I had 4.11s though. When I added meth and turned up the boost to 8, I had full spool about the same time. Made good power though. I ran 12.0 @ 120 w/2.0 60ft on a 3700+lb car.
Originally Posted by enginjoe
Your car is just like mine was. T67, LTs, ORY full spool 4000 - 4500. I wrapped the y too. I had 4.11s though. When I added meth and turned up the boost to 8, I had full spool about the same time. Made good power though. I ran 12.0 @ 120 w/2.0 60ft on a 3700+lb car.
I guess I should probably wait til I get these manifolds on and 2.5" Y on before i keep trash talking my own car lol.
Originally Posted by 99camarosupersport
Hey man, do the cast iron 99+ manifolds work best or the 98 tubular, they were different correct?
I'm trading a buddy of mine my Hooker LT's and my ORY for some stock cast manifolds and a stock catless y pipe, which those had an oval design correct...are those "best" or a tubed 2.5" Y?
I'm trading a buddy of mine my Hooker LT's and my ORY for some stock cast manifolds and a stock catless y pipe, which those had an oval design correct...are those "best" or a tubed 2.5" Y?
Originally Posted by JAvenger007
I was discussing this with someone the other day. My understanding is that the 98-99 manifolds are thicker but the 2000-02 ones are easier to port and from what I've heard, the earlier ones can hardly be ported at all.
It just seems like an endless loop to me. I picture smaller diameter tubing creating more velocity to spin the turbo but creating more backpressure on the motor that is trying to flow 500+hp. The heat thing is like smaller tubing I guess since the heat causes the air to expand more.
anymore input from turbovert or anyone with more insight on this?
blacksi, more backpressure = faster spool times so the quicker that air is pushed back to the intake and exiting the car, thats how i see that thought..?
Also, is running the engine at 180* actually hurting my spool time, should i swap the aftermarket radiator for a stock one and bring it back up to 210*?
blacksi, more backpressure = faster spool times so the quicker that air is pushed back to the intake and exiting the car, thats how i see that thought..?
Also, is running the engine at 180* actually hurting my spool time, should i swap the aftermarket radiator for a stock one and bring it back up to 210*?
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It's all about the heat which is related to all the other things. There were a couple of great threads on this where engineermike and some others gave some good explanations. I thought of one more thing; you never said what A/R you had. If you have the .96 that will make you spool slower too. The .81 is probably the best option.
Originally Posted by enginjoe
It's all about the heat which is related to all the other things. There were a couple of great threads on this where engineermike and some others gave some good explanations. I thought of one more thing; you never said what A/R you had. If you have the .96 that will make you spool slower too. The .81 is probably the best option.
Originally Posted by 99camarosupersport
Newb question what does A/R stand for?
Here is a good writeup:
http://www.forcedinductions.com/help.htm
Originally Posted by RealQuick
Oh yeah, your A/R is usually cast into the side of your exhaust housing, so you can go look and see what it is.
Last edited by enginjoe; Aug 29, 2007 at 01:48 PM.
Originally Posted by enginjoe
It's the area of the tubo inlet divided by the radius of the exhaust side. The smaller the number, the quicker you spool and the sooner it chokes off. It is a trade off between spool time and max power usually.
Ok cool thanks guys, I was just about to say wouldn't that be fixed to the turbo after reading that writeup... I guess Garrett sells the GT67's with varying A/R's then?
Going to check A/R now, will edit post when I get it.
Going to check A/R now, will edit post when I get it.
Originally Posted by gametech
The good thing is that the housings are the cheapest part of the turbo and easy to swap.
But i do see what you mean, anyway I'm not looking into doing that anytime soon. perhaps as a VERY last option, and only if i could trade or something.
keep in mind you will need to retune the car with the .81 housing both to take advantage of it and to make sure your AFR is in check due to the change in spool.
Cant remember if I posted here but heres my results so far all on a 60-1, wrapped exhaust, stock manifolds/ypipe:
-.70 housing full spool at 2500rpm but choked quite a bit both in hp and too much backpressure. ECTs were high and there was so much KR that you couldn't actually get good power out of it.
-.96 housing full spool at 3500. Less KR and felt MUCH stronger. During my logging run I gave it full boost for the first/only time (which is how I got these results to share) and completely blew tires loose in 3rd gear before even hitting full 6psi (which felt like it came in fast but logging showed around 3500). Granted im running fuzion ZRi tires though
Now im running the .81 that just came in from forced inductions. The car gets tuned next week so I will post a graph with results. IMO its the best option for a car making under 700hp
Cant remember if I posted here but heres my results so far all on a 60-1, wrapped exhaust, stock manifolds/ypipe:
-.70 housing full spool at 2500rpm but choked quite a bit both in hp and too much backpressure. ECTs were high and there was so much KR that you couldn't actually get good power out of it.
-.96 housing full spool at 3500. Less KR and felt MUCH stronger. During my logging run I gave it full boost for the first/only time (which is how I got these results to share) and completely blew tires loose in 3rd gear before even hitting full 6psi (which felt like it came in fast but logging showed around 3500). Granted im running fuzion ZRi tires though
Now im running the .81 that just came in from forced inductions. The car gets tuned next week so I will post a graph with results. IMO its the best option for a car making under 700hp
