large or mild streeport?
03-14-03, 08:21 PM
#1
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large or mild streeport?
Hey guys,
My car is in the shop for an engine rebuild and I was wondering what porting I should get done. I'm also going single turbo (gt 35/40) at the same time so I'm not sure what I should do. My target rwhp is probably like 450 more or less but not much more than that. I also heard there is lag in the low end with a larger port. I did some research about porting but I'm still torn between the two. One of my main gripes is that with a Large streeport, it doesn't idle as well and has a pulsing sound. I know a lot of people like that pulsing tone, but I dont want it to sound (whack.. whack..whack)like its almost about to die. Does anyone have any videos of large streeported motors (I've seen nocabs video already...very nice car). Additionally, I was wondering if 1300cc injectors will be enough to support the 35/40. I'm not aiming to boost too much but I was wondering what is a safe amount to boost with 1300ccs. Sorry for the long post, thanks for reading and hope to hear from you guys soon.
My car is in the shop for an engine rebuild and I was wondering what porting I should get done. I'm also going single turbo (gt 35/40) at the same time so I'm not sure what I should do. My target rwhp is probably like 450 more or less but not much more than that. I also heard there is lag in the low end with a larger port. I did some research about porting but I'm still torn between the two. One of my main gripes is that with a Large streeport, it doesn't idle as well and has a pulsing sound. I know a lot of people like that pulsing tone, but I dont want it to sound (whack.. whack..whack)like its almost about to die. Does anyone have any videos of large streeported motors (I've seen nocabs video already...very nice car). Additionally, I was wondering if 1300cc injectors will be enough to support the 35/40. I'm not aiming to boost too much but I was wondering what is a safe amount to boost with 1300ccs. Sorry for the long post, thanks for reading and hope to hear from you guys soon.
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03-14-03, 09:00 PM
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1) You can go with a very large streetport and still have a smooth idle. Go with a big streetport.
2) 550/1300 cc is good for at least 450 rwhp but all cars are different. There are other factors such as fuel pump, fuel quality etc. Max Cooper has a good site:
http://www.maxcooper.com/rx7/how-to/...tem/calcs.html
2) 550/1300 cc is good for at least 450 rwhp but all cars are different. There are other factors such as fuel pump, fuel quality etc. Max Cooper has a good site:
http://www.maxcooper.com/rx7/how-to/...tem/calcs.html
03-16-03, 03:56 AM
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Hi [Dk]Rx7. I just got a medium sized street port and a T04E single turbo. I haven't been able to go past 5500 rpm cuz I'm still breaking in the motor and I also need to have XS Eng dyno tune the PowerFC again. But from how the car feels so far, I wish I would have gone with the large street port and a larger turbo.
My goal is 400HP to the wheels at about 14-15PSI but I have read about many others getting the same HP with lower boost. And lower boost is definitely a big plus.
Anyhow, what city do you live in? And what wheels are those in your Avatar? I'm looking for some ideas so I can sell the ones I have now.
Take care,
Tom
My goal is 400HP to the wheels at about 14-15PSI but I have read about many others getting the same HP with lower boost. And lower boost is definitely a big plus.
Anyhow, what city do you live in? And what wheels are those in your Avatar? I'm looking for some ideas so I can sell the ones I have now.
Take care,
Tom
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03-17-03, 03:11 AM
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It should have slightly less lowend, but the larger ports will actually spool the turbo faster. End result: It'll probably have a bit less power below 3K, but above that it'll be better than a mild SP
03-17-03, 03:36 AM
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yea...the main things holding me back is the decrease in low end power and the lumpy idle. ANyone have any videos of a large streetport FD with good smooth idle? THanks and hope to hear from you guys soon.
03-17-03, 10:32 PM
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Do a search on Nocab....and you should find alot of things about large steetport and gt35/40. I would say go for the large streetport. It really helps the turbo spool and beathe. You won't regret it.
03-17-03, 10:57 PM
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Originally posted by Mr rx-7 tt
1) You can go with a very large streetport and still have a smooth idle. Go with a big streetport.
2) 550/1300 cc is good for at least 450 rwhp but all cars are different. There are other factors such as fuel pump, fuel quality etc. Max Cooper has a good site:
http://www.maxcooper.com/rx7/how-to/...tem/calcs.html
1) You can go with a very large streetport and still have a smooth idle. Go with a big streetport.
2) 550/1300 cc is good for at least 450 rwhp but all cars are different. There are other factors such as fuel pump, fuel quality etc. Max Cooper has a good site:
http://www.maxcooper.com/rx7/how-to/...tem/calcs.html
I used the super turbo rotary, 550x1300 and stock fuel pressure and 80% duty and only got only enough to support 383rwhp.
03-17-03, 11:47 PM
#14
Try:
0.62 BSFC
45 psi fuel
90% duty
13% drivetrain losses
520 HP
452 RWHP
That's pushing it a bit, but it isn't unreasonable.
The page is setup to make conservative estimates. I don't do any funny math, but the recommended maximums and stuff are designed to keep things conservative. I want people to end up with more capacity than they need, rather than too little.
-Max
0.62 BSFC
45 psi fuel
90% duty
13% drivetrain losses
520 HP
452 RWHP
That's pushing it a bit, but it isn't unreasonable.
The page is setup to make conservative estimates. I don't do any funny math, but the recommended maximums and stuff are designed to keep things conservative. I want people to end up with more capacity than they need, rather than too little.
-Max
03-19-03, 06:54 PM
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yea it is. I thought it over and I'm most likely going to upgrade to the 1600cc's and sx regulator so I dont work my fuel system too hard when the power is needed. I was just curious, what else do I need when I go with a larger fuel system? (something with resistors, low impedance and the PowerFc?) My mods will be the following: gt 35/40, cb/dp/mp , intake, pulleys, the new upgrade fuel system (1600cc, supra fuel pump, regulator), Power FC w/commander, and large streetport. With everything installed, can or should I even drive my car outta the shop? I'm guessing my car will be running super rich without even being tuned. What should I do with my situation? I'm going to break the new motor in for like 500miles, but I dont want to risk driving the car with everything newly installed (fmic, single turbo, fuel system, etc) if its not safe to even drive it moderately. Anyone have any suggestions? THanks and hope to hear from you guys soon.
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