86 RX7 GXL (new project)

[Metal MP5]

So yeah, like i said in the Cams group buy thread, my proteg pissed me off again, runs like crap n stuff and this opportunity presented itself ... being the mazda fan that i am, i just couldnt let it go. So i'm buying one of the 28 cars that Focus owns (lol), an 1986 RX7 GXL

it only has very very minor little tiny spots of rust that i will have fixed during the winter. TII swap next summer maybe, we'll see. i'll take this one slow instead of going all out in the 1st 6 months like i did with the Proteg, document stuff and take pictures ... step by step. Went to the local Mazda dyno meet last saturday and it did 107.5hp at the wheels (stock crank hp is 146). It's a very nice little car, fun to drive. I just HAD to buy it ... y'know ... it's an rx7 hehe.

Here's a few pics ... look at that engine bay. it's 20 years old and it's cleaner than my 2003.5 MSP

http://www.msprotege.com/members/Metal%20MP5/RX7/IMG_2069.jpg
http://www.msprotege.com/members/Metal%20MP5/RX7/IMG_2070.jpg
http://www.msprotege.com/members/Metal%20MP5/RX7/IMG_2071.jpg
http://www.msprotege.com/members/Metal%20MP5/RX7/IMG_2072.jpg
http://www.msprotege.com/members/Metal%20MP5/RX7/IMG_2073.jpg

Dyno sheet. All stock

http://www.msprotege.com/members/Metal%20MP5/RX7/rx7_dyno_09-2006_stock.jpg


***Update: 10/11/2006
I took the car to the track monday and did 5 runs. Best one was 16.597 @ 87.008mph ... all other runs were between 16.7 to 16.9 @ 85.9 to 86.0mph. Best run was #3. duno how i gained 1mph in that run. The tires really suck, or i can't drive RWD (one of the two lol), my best 60' was 2.421 and best RT was .034 all in the same 16.5 run

i'll scan the time slip later and add it to the 1st post. So now i have stock numbers ... can't wait to see the progression as i'll change tires (they are almost bald National XT5000 lol) and later on do the engine swap ... i am still undecided; should i keep it simple and do the TurboII swap next year or wait an extra year (maybe 2) and get a 20B. I would keep the TurboII engine stock for the first year, then maybe send it to get street ported and i just recently saw pictures of a custom parallel twin turbo setup on an FC that looked very interesting.

Picture of his dyno sheet
http://www.rx7club.com/attachment.php?attachmentid=199124
Pictures of the manifold
http://www.rx7club.com/attachment.php?attachmentid=198978
http://www.rx7club.com/attachment.php?attachmentid=198979

The car puts down 255whp @ 7psi, full boost at 3000rpm on twin GT25R.
Looks fairly easy to make so we'll see what happens ... projects always change, depending on funds n stuff so i don't know yet. What i know is that nothing is happening until next summer or until i get the rust fixed and a new paint job.

 

[Metal MP5]

reserved 1

 

[Metal MP5]

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[Metal MP5]

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[Metal MP5]

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[Metal MP5]

reserved 5

 

[Metal MP5]

reserved 6

 

[Metal MP5]

reserved 7 (this should be enough)

 

[evilmonkeyMSP]

awesome...good luck I should be starting to search for mine after the first of the year

 

[Focus]

I'm glad you like the car !

 

[evilmonkeyMSP]

how much did you pay if you dont mind me asking?

 

[ZoomZoomH]

107whp for a S4 NA.... looks like the intake port valves may be stuck shut, killing all your top end power...

 

[Focus]

107whp for a S4 NA.... looks like the intake port valves may be stuck shut, killing all your top end power...

Are you talking about the 5th and 6th ports ?

 

[Metal MP5]

you guys figure that one out cuz i have no idea what you're talking about lol

i need an RX7 for dummies book

i thought the rotary should make more power as the rpm goes up ... so maybe you are right and something is wrong with the intake ports because it feels like it's dieing at over 6500rpm, doesn't pull as much. i'll scan the dyno sheet, you'll see the power curve goes down after about 6000rpm

 

[ZoomZoomH]

Are you talking about the 5th and 6th ports ?

yes... VDAI or something like that

i had the same issue with my S5 FC when i had it... it dynoed a whopping 103hp when they were stuck.... car just dies after 5000rpm, no acceleration at all.

 

[ZoomZoomH]

FYI, a healthy running NA rotary engine should pull hard all the way to redline, and then some

 

[Metal MP5]

yep yep it does feel like that ... doesn't pull very much passed 5000rpm. i said 6500 i think in my other post but it could be 5000

 

[evilmonkeyMSP]

how would one fix this problem?

FYI, a healthy running NA rotary engine should pull hard all the way to redline, and then some

 

[ZoomZoomH]

how would one fix this problem?

pull the intake manifold, clean or replace the control rods that opens/closes the intake ports, and reinstall manifold.

could get expensive if you take it to a rotary specialist to have it fixed like I did (I think it cost me $600-ish to have that fixed). Time to invest in a Hayne's manual if you're gonna DIY fix it!!

 

[JDuncan]

I would suspect that the 5th/6th ports are't activating correcty. On the S4's they are activated by exhaust pressure IIRC. There is no VDI on the S4. If it has aftermarket exhaust then you might want to check to make sure provisions were made to provide that activation.