New weight saving/performance project started...

rick2 · 07-11-2007, 03:32 AM

Just a teaser...

We're exploring cat deletion... (on our way to a freer flowing, and mucho-lighter exhaust setup to drop valueable performance robbing pounds from the racecar.)

only problem is w/the fuel injected 13B, the 5th&6th intake ports only open w/the help of exhaust backpressure from one of the cats... and above 4k-ish rpm's, those extra ports generate some noticable power...

We've got some ideas, and we're gonna test 'em w/this testpipe... I'll give more details later, once we get it all welded up and test fitted

RageRX7 · 07-11-2007, 12:40 PM

NICE Rick, I like where this is going.. what's your target?

Jimbo · 07-11-2007, 03:01 PM

Great idea Rick, are you going with an active flap type thing?

rick2 · 07-11-2007, 10:51 PM

no flap... we're trying to replace the heavy and restrictive stock midpipe with it's 3 (yes, three!!!) catalytic converters..

as far as goals... heres the results from when we got the car on the scales as a baseline:

So, stockish, its 2600+ lbs... and not very balanced (each corner of the car is at a different weight:

I don't have any lofty goals of getting it down to miata-ish weight... (aka sub 2k lbs...)

I'm thinking getting it to the neighborhood of 2300 lbs would be a good goal. As far as power goals... dunno yet...

As far as the pipe... w/the flanges welded on and it bolted up... ports 5+6 wont open... not enough backpressure... and with the stock air pump, we got some backfiring going on...

Supersonic · 07-12-2007, 03:32 PM

Wow that's way off, getting those corner weights done alone should make a big improvment.

Looks like this is going to be an interesting project!

KevinRX7 · 07-13-2007, 05:56 PM

Very cool. Looking forward to seeing how this turns out!

rick2 · 07-15-2007, 07:33 AM

Well, while we're still working on the exhaust problem (well okay, the straight pipe works well... just cant get the 5+6 ports to open due to lack of exhaust backpressure... )

we're exploring other options to get the ports to open at the right RPM ranges... but in the mean time, the stock cats were reinstalled due to the fact that we'd miss tonights autocross without them, since we didn't want to miss out on the power increase from the ports....

So, instead, a couple other things we had planned to do after the exhaust got done.

Removed the A/C compressor, condensor and piping. Removed the radio/tape deck, removed the rear seats and installed the rear carpeting/storage bins from our GXL parts car (our class requires stock carpeting... so we went with the storage bins instead of the broken jumpseats... incidentally, the cargo bins are the PERFECT size to store a helmet! more proof that the RX7 is the perfect race car

)
Oh, and we also removed the aftermarket airhorn that the previous owner installed...

Look, no A/C!

Also stole the seats out of the GXL, as they arent as sun rotted, and have slightly better side support.

Now, we've got her under 2600 lbs (lol, just barely- 2599 to be exact!) corner weights have slightly improved towards neutral, as well:

Oh, and we installed the camber plates we were gonna save till we got all of our power-related issues solved:

did a rough alignment using only tape measures and a cheesy cheap magnetic protractor...

resulted in a dramatic increase in forward grip, and turn in/front bite...

so much so that the car actually was crazy loose the first few runs before some air pressure adjustments tonight... Learned a ton more about this car tonight...

Oh, and we've still got some ideas to make the cheap custom exhaust work, just need to test a few things... trying to save the Diff. swap and a few other things until we've gotten the exhaust ideas working... (hell, we wanted to wait on the a/c deletion and camber plates/alignment... we just ran out of time, and realised they were EASY and fast to do... ehe... the diff swap should be rather time consuming, too...)

Will post more as we make more progress

KevinRX7 · 07-16-2007, 02:25 PM

Getting better already!

Looks like relocating the battery could help as well. Looking forward to seeing how you overcome the exhaust / port problem

Supersonic · 07-16-2007, 09:25 PM

Tape measure and protractor? You know that thought would have never crossed my mind

Looks like it's coming along.. nice stuff

rick2 · 07-17-2007, 02:32 AM

Quote:

Originally Posted by KevinRX7

Getting better already!

Looks like relocating the battery could help as well. Looking forward to seeing how you overcome the exhaust / port problem

yea, thats the first thing I recommended... but then my pops came at me w/ some of the suspension tricks they used to do when he was helping crew a late model stock car to change corner weights/crossweight when you cant remove anymore or relocate anymore due to rules limitations...

Quote:

Originally Posted by Supersonic

Tape measure and protractor? You know that thought would have never crossed my mind

Looks like it's coming along.. nice stuff

yea, you take a pair of plates of metal w/matching notches on each side at the bottom to hold the tape measures (requires 2 tapes) and holes more inboard to help center, and can measure the toe in/out

expensive example:
Longacre Racing toe plates

and a magnetic protractor/angle finder (usually used in welding up frames and stuff) to figure out the camber

used one similar to this:
Harbor Freight cheapo angle finder

the alignment isn't super precise... but we got it close enough w/out droppign $100+ at an alingment shop... and most dedicated race crews use similar stuff at the track ehe

KevinRX7 · 07-17-2007, 03:45 PM

What ever works right Rick?

Better then having your tires looks like the girl I was out with last night.. she had blue eyes. One blew left and one blew right

Aluminum · 07-18-2007, 06:49 PM

Wow, that looks like a lot of work.

Great job so far!

rick2 · 07-30-2007, 05:32 AM

got some more work done today...

cut a new hole at the "pinch" curve of the testpipe, hoping theres slightly more backpressure there for our new sniffer pipe design (the hole to the right was welded shut right after we took this pic)

bent us up a new sniffer pipe, and I cut and "ported" the opening to try and simulate as much backpressure as possible w/out ruining the flow of the bigger/straighter pipe:

a little more welding later, the (nearly) finished product:

still need to fab a flange to hook the new sniffer pipe to the 5+6 ports, and then test it out...

if this works, our next step is to delete the "Y" after the pipe, and convert to one high flow muffler, instead of 2 heavy ones

RageRX7 · 07-30-2007, 12:38 PM

Awesome stuff Rick, can you modify it ever so slightly if need be to adjust backpressure if you still have trouble with the ports?

Mindcore · 07-30-2007, 02:11 PM

I thought there was going to be a mary had a little lamb joke what with that little sheep catcher you made

SteveO · 08-02-2007, 02:01 PM

Awesome!!!! Rick you'll need to give me your opinions when it's all done up, this is exactly what I should be doing.

rick2 · 08-02-2007, 10:16 PM

Quote:

Originally Posted by RageRX7

Awesome stuff Rick, can you modify it ever so slightly if need be to adjust backpressure if you still have trouble with the ports?

well, we can restrict flow if they engage too quickly... if they still don't engage w/that work... well it will have to be back to the drawing board

hopefully this weekend I can get it finished/tested out

AZNPWR · 08-05-2007, 11:45 AM

That looks amazing Rick... good luck this weekend!!

07-11-2007, 03:32 AM	#1 (permalink)
rick2 Senior Member Join Date: Jun 2007 Location: Henderson, NV Posts: 243	New weight saving/performance project started... Just a teaser... We're exploring cat deletion... (on our way to a freer flowing, and mucho-lighter exhaust setup to drop valueable performance robbing pounds from the racecar.) only problem is w/the fuel injected 13B, the 5th&6th intake ports only open w/the help of exhaust backpressure from one of the cats... and above 4k-ish rpm's, those extra ports generate some noticable power... We've got some ideas, and we're gonna test 'em w/this testpipe... I'll give more details later, once we get it all welded up and test fitted

07-15-2007, 07:33 AM	#7 (permalink)
rick2 Senior Member Join Date: Jun 2007 Location: Henderson, NV Posts: 243	Well, while we're still working on the exhaust problem (well okay, the straight pipe works well... just cant get the 5+6 ports to open due to lack of exhaust backpressure... ) we're exploring other options to get the ports to open at the right RPM ranges... but in the mean time, the stock cats were reinstalled due to the fact that we'd miss tonights autocross without them, since we didn't want to miss out on the power increase from the ports.... So, instead, a couple other things we had planned to do after the exhaust got done. Removed the A/C compressor, condensor and piping. Removed the radio/tape deck, removed the rear seats and installed the rear carpeting/storage bins from our GXL parts car (our class requires stock carpeting... so we went with the storage bins instead of the broken jumpseats... incidentally, the cargo bins are the PERFECT size to store a helmet! more proof that the RX7 is the perfect race car ) Oh, and we also removed the aftermarket airhorn that the previous owner installed... Look, no A/C! Also stole the seats out of the GXL, as they arent as sun rotted, and have slightly better side support. Now, we've got her under 2600 lbs (lol, just barely- 2599 to be exact!) corner weights have slightly improved towards neutral, as well: Oh, and we installed the camber plates we were gonna save till we got all of our power-related issues solved: did a rough alignment using only tape measures and a cheesy cheap magnetic protractor... resulted in a dramatic increase in forward grip, and turn in/front bite... so much so that the car actually was crazy loose the first few runs before some air pressure adjustments tonight... Learned a ton more about this car tonight... Oh, and we've still got some ideas to make the cheap custom exhaust work, just need to test a few things... trying to save the Diff. swap and a few other things until we've gotten the exhaust ideas working... (hell, we wanted to wait on the a/c deletion and camber plates/alignment... we just ran out of time, and realised they were EASY and fast to do... ehe... the diff swap should be rather time consuming, too...) Will post more as we make more progress Last edited by rick2 : 07-15-2007 at 07:35 AM.

07-30-2007, 05:32 AM	#13 (permalink)
rick2 Senior Member Join Date: Jun 2007 Location: Henderson, NV Posts: 243	got some more work done today... cut a new hole at the "pinch" curve of the testpipe, hoping theres slightly more backpressure there for our new sniffer pipe design (the hole to the right was welded shut right after we took this pic) bent us up a new sniffer pipe, and I cut and "ported" the opening to try and simulate as much backpressure as possible w/out ruining the flow of the bigger/straighter pipe: a little more welding later, the (nearly) finished product: still need to fab a flange to hook the new sniffer pipe to the 5+6 ports, and then test it out... if this works, our next step is to delete the "Y" after the pipe, and convert to one high flow muffler, instead of 2 heavy ones __________________ '87 Blue RX-7 Coupe - the race car '99 Green MX-5 Roadster - my daily '77 RX-3 SP - the project car

07-30-2007, 02:11 PM	#15 (permalink)
Mindcore Administrator Join Date: May 2007 Location: Look Out!!! Posts: 1,299	I thought there was going to be a mary had a little lamb joke what with that little sheep catcher you made __________________ core Mazda Forums .

08-02-2007, 02:01 PM	#16 (permalink)
SteveO Member Join Date: May 2007 Posts: 92	Awesome!!!! Rick you'll need to give me your opinions when it's all done up, this is exactly what I should be doing. __________________ 94 RX7..no seats

07-11-2007, 12:40 PM	#2 (permalink)
RageRX7 Senior Member Join Date: Jun 2007 Posts: 164	NICE Rick, I like where this is going.. what's your target?

07-11-2007, 03:01 PM	#3 (permalink)
Jimbo Senior Member Join Date: May 2007 Location: Toronto Posts: 161	Great idea Rick, are you going with an active flap type thing?

07-11-2007, 10:51 PM	#4 (permalink)
rick2 Senior Member Join Date: Jun 2007 Location: Henderson, NV Posts: 243	no flap... we're trying to replace the heavy and restrictive stock midpipe with it's 3 (yes, three!!!) catalytic converters.. as far as goals... heres the results from when we got the car on the scales as a baseline: So, stockish, its 2600+ lbs... and not very balanced (each corner of the car is at a different weight: I don't have any lofty goals of getting it down to miata-ish weight... (aka sub 2k lbs...) I'm thinking getting it to the neighborhood of 2300 lbs would be a good goal. As far as power goals... dunno yet... As far as the pipe... w/the flanges welded on and it bolted up... ports 5+6 wont open... not enough backpressure... and with the stock air pump, we got some backfiring going on...

07-12-2007, 03:32 PM	#5 (permalink)
Supersonic Senior Member Join Date: May 2007 Location: New York, NY Posts: 345	Wow that's way off, getting those corner weights done alone should make a big improvment. Looks like this is going to be an interesting project!

07-13-2007, 05:56 PM	#6 (permalink)
KevinRX7 Senior Member Join Date: Jun 2007 Location: Bay Area Posts: 132	Very cool. Looking forward to seeing how this turns out!

07-16-2007, 02:25 PM	#8 (permalink)
KevinRX7 Senior Member Join Date: Jun 2007 Location: Bay Area Posts: 132	Getting better already! Looks like relocating the battery could help as well. Looking forward to seeing how you overcome the exhaust / port problem

07-16-2007, 09:25 PM	#9 (permalink)
Supersonic Senior Member Join Date: May 2007 Location: New York, NY Posts: 345	Tape measure and protractor? You know that thought would have never crossed my mind Looks like it's coming along.. nice stuff

07-17-2007, 03:45 PM	#11 (permalink)
KevinRX7 Senior Member Join Date: Jun 2007 Location: Bay Area Posts: 132	What ever works right Rick? Better then having your tires looks like the girl I was out with last night.. she had blue eyes. One blew left and one blew right

07-18-2007, 06:49 PM	#12 (permalink)
Aluminum Member Join Date: Jul 2007 Posts: 51	Wow, that looks like a lot of work. Great job so far!

07-30-2007, 12:38 PM	#14 (permalink)
RageRX7 Senior Member Join Date: Jun 2007 Posts: 164	Awesome stuff Rick, can you modify it ever so slightly if need be to adjust backpressure if you still have trouble with the ports?

08-05-2007, 11:45 AM	#18 (permalink)
AZNPWR Member Join Date: Jun 2007 Posts: 52	That looks amazing Rick... good luck this weekend!!