4A-GE MK1 Engine new to mr N/A, i swear, this car is faster than it should be.. - Page 3

te51levin · 03-24-2008, 07:54 PM

Quote:

Originally Posted by 4W4K3

What's a book?

It's a kind of analog internet device, made of "trees" (I can explain them too if need be), used back in the cowboy and Indian days, back before DSL was widely available. Some old farts like me still like them because they are not subject to misapplication and misinterpretation by every kid with a keyboard and the desire to see his own thoughts on a forum or Myspace page.

Things ain't like they used to was...

Recklesss · 03-24-2008, 07:55 PM

why write a book when you can pee in the snow?

TechX · 04-17-2008, 09:31 PM

It is undeniable that backpressure robs horsepower, but as Aaron stated before cutting off your exhaust to make an annoying bumblebee will not help your horsepower either. The correct ways of raising your performance without becoming annoying is very simple. Create a better breathing atmosphere, colder cleaner and more air is the key. Give it a nice sound, if your stuff is old you run the chance of leaks, cracks, and low performance. Headers, decent exhaust pipe, and reliable/tested performance muffler. Change the oil, oil filter, fuel filter, plugs, wires, cap and rotor. Then have it tuned(by someone who knows what they are doing) and you will notice a great improvement.

If you are looking for anything more, then be ready to shell out the money. Your options range from 20v or 16v smallport topend. The lower end will cost you considerable more to change, just keep in mind, it was already stated a 4agze lower willnot increase power by itself. Changing the pistons, crank, and rods in the bottom end will however give you a larger HP curve to add to, and will in itself give you more options based on the compression ratio you build towards.

As another form of performance you have turbo, super, or twin charging your N/A, or just stop wasting time and do an entire engine swap and possible transmission as well if you are looking for a different gear setup.

There are limitless options as to what you can do with your car, it just depends on how much money you have and do you have the time and knowledge to do it yourself or money to pay someone. One of my boys is currently finishing up a 1jze(jap spec supra engine) into a Mazda RX-7. There are a lot of swaps that have been tried with the MK1, but feel free to explore and fill in the rest of us. Thanks.

4W4K3 · 04-17-2008, 10:05 PM

From what I've heard on the forums and seen from a few dyno graphs upgrading to after market headers gives you little to no performance gains. At best I think I've seen 3WHP. If yours is cracked or rusted then by all means get new ones, otherwise I wouldn't spend the money.
Speaking only from a stock perspective. If you have other modifications that have increased power then the stock headers may turn into a bottleneck, but you'd have to be well over stock performance.

TechX · 04-17-2008, 10:15 PM

Your entirely right, the upgrade of headers alone isn't viable for the money you will spend, it would only be a "good" upgrade if you were applying more than just that individual upgrade. Performance is the key, and as it does open up the flow of the exhaust, the rest of the exhaust and the amount of exhaust coming out if the head make a difference, again most of the upgrades you make are very slight for each individual upgrade and even tuned only make a difference when you add all the +3, +7, +?? up in the end.

F0Bman · 04-30-2008, 07:49 PM

I agree.

LokiRx7 · 05-01-2008, 02:52 PM

This debate is much like the intake porting depate, mostly because what is true with the intake is largely true with the exhaust.

Too small of a port, or exhaust port (same applies to exhaut pipe and intake pipe) Will cause excessive backpressure. No engine 'requires' backpressure. Anyone who tells you that you need backpressure knows nothing about what they are talking about.

What an engine needs is exhaust velocity, and with too large of an exhaust you will lose exhaust velocity. Some engines have very little exhaust velocity to help high rpm power at the expense of low end torque. We drive street cars and need to find a healthy medium.

The same rings true with porting, there is a such thing as too much porting or too big of an exhaust. I have read on some japanese 4A-GE specific tuning sites that the optimum exhaust diameter for this engine is between 2 inch and 2.5 inches. That was for an AE86/AE92. Depending on the length of your exhaust and the amount and severity of the bends is what should determine the diameter.

Alot of bends will make for a longer exhaust, it will probably be good to err on the larger side of 2.5 inches. Fewer bends will make for a shorter exhaust, I would shoot for around 2 inches. Also, I personally wouldnt use a glasspack on our cars. I would look for a nice chambered muffler, I have a Flowmaster, and I would have to reccomend it.

TechX · 05-01-2008, 11:19 PM

Agreed. Also, good information on exhaust sizes, my entire exhaust was rusted, and my engine hadnt run in 7 years, but I finally got the fuel pump replaced, and took the entire exhaust from the flex pipe to the muffler off. Broke bolts all over due to the severity of the rust. I'm going to cut the flex loose and cat, check inside the cat to make sure its not collapsed or anything and then I'm going to reassemble an exhaust with the flex and cat and just port it out the back so I can finish all the other work then I'll put a muffler on it. I'm going to pop a post up about the engine though, I'm having some probs and I think someone might be able to answer... stalling out

it's broke, help...

DCmr16 · 03-20-2010, 11:52 PM

gotta throw this out there....the gze internals would affect the power...by lowering it, they are supercharged internals.....meaning lower compression ratio, unless you meant only the crank and rods.

toyotaspeed90 · 03-22-2010, 04:07 PM

Quote:

Originally Posted by E T Haggis

what do you think a straight pipe right from the headers does for you?

gets you pulled over.....

and to correct one thing.... because it was bugging the crap out of me...

in 1987 the 4age 16V went from a 3 rib to a 7 rib block (block... not shortblock). The 4agze had it's debut in 1988 in the US on the MR2 only. It's debatable about pistons -- but essentially the shortblocks were the same minus the pistons. More likely than not your car has stock n/a pistons in it as it's an '87 with 72k miles.... and even if it's a stock motor from another car (4age) it probably is still an n/a motor... you would have lower performance with a gze shortblock.

DCmr16 · 03-22-2010, 10:44 PM

the blok is the same as lon as th n/a is 7 rib. No ****ng tings such as knocksensor.

toyotaspeed90 · 03-23-2010, 04:05 PM

Quote:

Originally Posted by DCmr16

the blok is the same as lon as th n/a is 7 rib. No ****ng tings such as knocksensor.

um.... read my post.

only thing I mis wrote was it was supposed to say debatable about the rods being different between n/a and gze... I've heard it both ways.

and your spelling/grammer is almost illegible.

DCmr16 · 03-23-2010, 06:15 PM

Quote:

Originally Posted by toyotaspeed90

gets you pulled over.....

... you would have lower performance with a gze shortblock.

Sorry about my phone typing. And i was refferring to the above quote. You said that the gze block would lower performance....it's the same. how would it lower the performance?

scottohno · 03-24-2010, 12:06 AM

is the original poster even in this thread anymore???

btw, i have 1/4 mile times for you

internet says 16.9

my mk1 with tons of crap in it and friend in passenger seat and empty on gas and my first run ever:16.9

the next few runs i was getting used to it, 16.7

then i took out the spare tire, trunk crap, got my sockets and took the passenger seat out (they made me put the driver seat back in) 16.1

that was with stock intake, 210,000 miles, a burning clutch cause i ran about 10 times in 4 hours, 87 octane (better for our cars, but thats an argument for another day) and did i mention the exhaust was stock manifold with a cherry bomb turbo muffler 3" in/out welded to the downpipe before the flex pipe? i have a header set and custom 2" exhaust and its not too loud and it sounds great and it added to the ass dyno readings. im sure it made me slower. i also have a weapon r short ram intake and a racing clutch thats not broken in with a 9lb flywheel and a destroyed transmission attached. im gonna take it once i swp the trans and break in the clutch, maybe better maybe worse. at least i wont burn the clutch

by the way, it is a PITa to get the trans out. hope it has a newer clutch.

toyotaspeed90 · 03-24-2010, 05:14 PM

Quote:

Originally Posted by DCmr16

Sorry about my phone typing. And i was refferring to the above quote. You said that the gze block would lower performance....it's the same. how would it lower the performance?

gze pistons are 8.0:1 and n/a ge pistons are 9.4:1. You lose compression and you lose power.

whore of babylon · 03-24-2010, 08:54 PM

He speaks the truth :P

alex canni · 03-24-2010, 09:14 PM

sorry for being rude or anything,but
1)its rear wheel drive
2)it weighs 1900 pounds
3)and the guy prolly did some mods to it befor he sold it to you,of corse its faster than a b16 civic.

good buy best of luck to you.

te51levin · 03-24-2010, 09:21 PM

Quote:

Originally Posted by alex canni

good buy best of luck to you.

I think "goodbye" would be more appropriate than "good buy", considering the OP hasn't been here in a year and a half.

Now we'll never know his secret speed recipes...

DCmr16 · 03-24-2010, 10:11 PM

you said the block. nothing about the entire engine...nothing about the rotating assembly. you said very clearly "GZE SHORTBLOCK"

FreeFall · 03-25-2010, 10:21 AM

Quote:

Originally Posted by alex canni

sorry for being rude or anything,but
1)its rear wheel drive
2)it weighs 1900 pounds
3)and the guy prolly did some mods to it befor he sold it to you,of corse its faster than a b16 civic.

good buy best of luck to you.

1900 pounds?!?!?!? is there no hood, trunk lid, seats, dash and quarter panels?!?!!?

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03-24-2008, 07:55 PM	#42 (permalink)
Recklesss Fck yo couch! Join Date: Jan 2008 Location: Oregon Posts: 636 Thanks: 9 Thanked 8 Times in 7 Posts iTrader Rating: (0/0%* )	why write a book when you can pee in the snow?

04-17-2008, 09:31 PM	#43 (permalink)
TechX TechnoComputerGearHead Join Date: Mar 2008 Location: Morgantown, WV Posts: 21 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	It is undeniable that backpressure robs horsepower, but as Aaron stated before cutting off your exhaust to make an annoying bumblebee will not help your horsepower either. The correct ways of raising your performance without becoming annoying is very simple. Create a better breathing atmosphere, colder cleaner and more air is the key. Give it a nice sound, if your stuff is old you run the chance of leaks, cracks, and low performance. Headers, decent exhaust pipe, and reliable/tested performance muffler. Change the oil, oil filter, fuel filter, plugs, wires, cap and rotor. Then have it tuned(by someone who knows what they are doing) and you will notice a great improvement. If you are looking for anything more, then be ready to shell out the money. Your options range from 20v or 16v smallport topend. The lower end will cost you considerable more to change, just keep in mind, it was already stated a 4agze lower willnot increase power by itself. Changing the pistons, crank, and rods in the bottom end will however give you a larger HP curve to add to, and will in itself give you more options based on the compression ratio you build towards. As another form of performance you have turbo, super, or twin charging your N/A, or just stop wasting time and do an entire engine swap and possible transmission as well if you are looking for a different gear setup. There are limitless options as to what you can do with your car, it just depends on how much money you have and do you have the time and knowledge to do it yourself or money to pay someone. One of my boys is currently finishing up a 1jze(jap spec supra engine) into a Mazda RX-7. There are a lot of swaps that have been tried with the MK1, but feel free to explore and fill in the rest of us. Thanks.

04-17-2008, 10:05 PM	#44 (permalink)
4W4K3 Some Skills Join Date: Feb 2008 Location: Texas Posts: 78 Thanks: 0 Thanked 6 Times in 6 Posts iTrader Rating: (0/0% )	From what I've heard on the forums and seen from a few dyno graphs upgrading to after market headers gives you little to no performance gains. At best I think I've seen 3WHP. If yours is cracked or rusted then by all means get new ones, otherwise I wouldn't spend the money. Speaking only from a stock perspective. If you have other modifications that have increased power then the stock headers may turn into a bottleneck, but you'd have to be well over stock performance.

04-17-2008, 10:15 PM	#45 (permalink)
TechX TechnoComputerGearHead Join Date: Mar 2008 Location: Morgantown, WV Posts: 21 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Your entirely right, the upgrade of headers alone isn't viable for the money you will spend, it would only be a "good" upgrade if you were applying more than just that individual upgrade. Performance is the key, and as it does open up the flow of the exhaust, the rest of the exhaust and the amount of exhaust coming out if the head make a difference, again most of the upgrades you make are very slight for each individual upgrade and even tuned only make a difference when you add all the +3, +7, +?? up in the end.

04-30-2008, 07:49 PM	#46 (permalink)
F0Bman Cage Fighter Join Date: Mar 2008 Posts: 252 Thanks: 0 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	I agree.

05-01-2008, 02:52 PM	#47 (permalink)
LokiRx7 MR2 + Flat Black = FAIL Join Date: Jan 2007 Location: N.C. Ohio Posts: 320 Thanks: 0 Thanked 15 Times in 14 Posts iTrader Rating: (1/100% )	This debate is much like the intake porting depate, mostly because what is true with the intake is largely true with the exhaust. Too small of a port, or exhaust port (same applies to exhaut pipe and intake pipe) Will cause excessive backpressure. No engine 'requires' backpressure. Anyone who tells you that you need backpressure knows nothing about what they are talking about. What an engine needs is exhaust velocity, and with too large of an exhaust you will lose exhaust velocity. Some engines have very little exhaust velocity to help high rpm power at the expense of low end torque. We drive street cars and need to find a healthy medium. The same rings true with porting, there is a such thing as too much porting or too big of an exhaust. I have read on some japanese 4A-GE specific tuning sites that the optimum exhaust diameter for this engine is between 2 inch and 2.5 inches. That was for an AE86/AE92. Depending on the length of your exhaust and the amount and severity of the bends is what should determine the diameter. Alot of bends will make for a longer exhaust, it will probably be good to err on the larger side of 2.5 inches. Fewer bends will make for a shorter exhaust, I would shoot for around 2 inches. Also, I personally wouldnt use a glasspack on our cars. I would look for a nice chambered muffler, I have a Flowmaster, and I would have to reccomend it.

05-01-2008, 11:19 PM	#48 (permalink)
TechX TechnoComputerGearHead Join Date: Mar 2008 Location: Morgantown, WV Posts: 21 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Agreed. Also, good information on exhaust sizes, my entire exhaust was rusted, and my engine hadnt run in 7 years, but I finally got the fuel pump replaced, and took the entire exhaust from the flex pipe to the muffler off. Broke bolts all over due to the severity of the rust. I'm going to cut the flex loose and cat, check inside the cat to make sure its not collapsed or anything and then I'm going to reassemble an exhaust with the flex and cat and just port it out the back so I can finish all the other work then I'll put a muffler on it. I'm going to pop a post up about the engine though, I'm having some probs and I think someone might be able to answer... stalling out it's broke, help...

03-20-2010, 11:52 PM	#49 (permalink)
DCmr16 newbie mk1 Join Date: Jan 2010 Location: des moines, IA Posts: 166 Thanks: 0 Thanked 4 Times in 4 Posts iTrader Rating: (0/0% )	gotta throw this out there....the gze internals would affect the power...by lowering it, they are supercharged internals.....meaning lower compression ratio, unless you meant only the crank and rods.

03-22-2010, 10:44 PM	#51 (permalink)
DCmr16 newbie mk1 Join Date: Jan 2010 Location: des moines, IA Posts: 166 Thanks: 0 Thanked 4 Times in 4 Posts iTrader Rating: (0/0% )	the blok is the same as lon as th n/a is 7 rib. No ****ng tings such as knocksensor.

03-24-2010, 12:06 AM	#54 (permalink)
scottohno control your hose Join Date: Feb 2009 Location: Fox Lake, IL Posts: 5,100 Thanks: 43 Thanked 93 Times in 83 Posts iTrader Rating: (7/100% )	is the original poster even in this thread anymore??? btw, i have 1/4 mile times for you internet says 16.9 my mk1 with tons of crap in it and friend in passenger seat and empty on gas and my first run ever:16.9 the next few runs i was getting used to it, 16.7 then i took out the spare tire, trunk crap, got my sockets and took the passenger seat out (they made me put the driver seat back in) 16.1 that was with stock intake, 210,000 miles, a burning clutch cause i ran about 10 times in 4 hours, 87 octane (better for our cars, but thats an argument for another day) and did i mention the exhaust was stock manifold with a cherry bomb turbo muffler 3" in/out welded to the downpipe before the flex pipe? i have a header set and custom 2" exhaust and its not too loud and it sounds great and it added to the ass dyno readings. im sure it made me slower. i also have a weapon r short ram intake and a racing clutch thats not broken in with a 9lb flywheel and a destroyed transmission attached. im gonna take it once i swp the trans and break in the clutch, maybe better maybe worse. at least i wont burn the clutch by the way, it is a PITa to get the trans out. hope it has a newer clutch.

03-24-2010, 08:54 PM	#56 (permalink)
whore of babylon Part time mechanic. Join Date: Apr 2007 Location: Tasmania Posts: 151 Thanks: 2 Thanked 3 Times in 3 Posts My Google Map iTrader Rating: (0/0% )	He speaks the truth :P

03-24-2010, 09:14 PM	#57 (permalink)
alex canni Cage Fighter Join Date: Dec 2009 Location: florida Posts: 135 Thanks: 6 Thanked 1 Time in 1 Post iTrader Rating: (0/0% )	sorry for being rude or anything,but 1)its rear wheel drive 2)it weighs 1900 pounds 3)and the guy prolly did some mods to it befor he sold it to you,of corse its faster than a b16 civic. good buy best of luck to you.

03-24-2010, 10:11 PM	#59 (permalink)
DCmr16 newbie mk1 Join Date: Jan 2010 Location: des moines, IA Posts: 166 Thanks: 0 Thanked 4 Times in 4 Posts iTrader Rating: (0/0% )	you said the block. nothing about the entire engine...nothing about the rotating assembly. you said very clearly "GZE SHORTBLOCK"