fast90rx7

I may be buying a car from a member on the forum. But I have one problem with this. He says it is not reving up to redline. He said that it will rev up to 6000 RPM fine but after that it seems like it has no power. He said that he thinks it the trans?? He said that the car reved all the way up to redline when it had a S4 N/A trans in it. But now with the TII trans it is doing this. Here is a list of what it has done to it.
1989 Mazda RX-7 GXL

Marlbro Red with Black Alum. hood
KYB Adjustable Shocks
Eibach Pro Street Springs
Eibach Sway Bars
S4 Engine with ALL S5 parts (everythign is S5 minus the housings and rotors, engine is pre mix)
Black Cloth Interior (in near perfect condition)
Has Rear Cargo Cover (pretty rare)
S4 TII Tranny
Custom Drive Shaft (car was orginally auto)
Rear bins
Warlbro Fuel Pump
All Emissions Removed and Blocked
No P/S
No A/C
Power Windows
Power Locks (which work)
Regrounded every major grouned except the ECU
15' Mazda BBS Wheels off a vert with newer tires
Heat Works
SilverStar White Headlights


ANYONE HAVE A CLUE WHAT IS CAUSING THIS??????

Thanks,
Mike

trainwreck517

iTrader: (1)

seems like 5th and 6th port induction system isn't functioning, do a search on that.

Turbo7MN

Could be VDI as well, I believe that's sround where the VDI activates.

Considering that the car is an S5, both of those systems operate off the stock airpump. You say the emissions stuff is removed, it's possible that he pulled off the aipump and didn't do anything with the 6PI or VDI.

bcool

My vote is on vdi also.

fast90rx7

VDI?????? Sorry im pretty new to rx7's. But im trying to learn. Just give me time.

fast90rx7

oh and what does the Air pump do.. Ill ask him if he removed the airpump. And I still don't get why he would say that it work completly fine when it has a N/A S4 trans in it. I just don't get how a trans would make a motor rev differently. I think he said that it also had a different driveshaft in it when it was revving fine. Could this be it?

88t2romad

vdi- variable dynamic intake

fast90rx7

Can you explain what it does. Also I talked to the owner, and he said that he is %100 sure that it is something with the trans. Any Ideas???

rxseven07

fuel filter clogged

fast90rx7

Ill buy the car from the guy if ppl agree that this doesn't seem like a serious problem. I mean when I get the car I can look into it futher, but I don't want to get this car and have it turn out to be something really serious. So do you guys think it is serious???? Ill ask the owner if the car pulls up to 6K like it should.

fast90rx7

Can anyone explain to me what VDI does??

Bump

BklynRX7

The s5 uim had what was called a vdi built into it. It remains close until a certain rmp when the airpump pumps air into it and opens it up allowing more airflow to the motor.

fast90rx7

So its almost like secondaires?? Because on my current car, a 92 taurus SHO, at 4000rpm vacum causes secondary butterflies open up. One is each runner that puts like twice the air flow into the motor.

I talked to the owner, and he said there is no airpump on it. So is there another way for this to work without the airpump??

And just another thing. Please correct me if im wrong but don't RX7's use T5 trannys? And is there any difference between a S4 TII tans and a S4 n/a trans??

kontakt

TII trans is beefier (mmm... beef), without the air pump you lose those systems that provide high RPM airflow (VDI, 6port) unless something was done to correct this (wired open 6ports, etc)

Turbo7MN

There's a big difference between N/A and TII trannies, the TII one is way stronger.

In my opinion, there is a 99% chance that this has nothing to do with the transmission. Unfortunately, I'm not exactly sure how the airpump activation for 6PI or VDI works on S5's, as I have only worked with the S4 system. However, I assure you that if there is no airpump, neither of those systems will work without another way of actuation.

Research the VDI a little more, tell the guy that the car is screwed to get a better price, buy it, and rig both systems to work electronically with RPM switches. I have a write-up on how to do that over on Team FC3S, if the problem is what I think it is it's a real easy fix.

-Darren

jthompson02

This is my car he is talking about.

All emissions including the air pump have been removed. The 6 ports are wired open. It is a S4 block with ALL S5 components on it (UI/LI/ETC). The car had a S4 N/A tranny on it before I put the TII tranny on it. THe car revved to 7k like it was supposed to without a problem. I blew that tranny though. So I put a TII tranny with the custom driveshaft (from mazdatrix, it allows a TII tranny to work with the auto rear end) in and it started doing this. I know for a FACT it has NOTHING to do with the smog syetm or anything liek that. Like I said I HAD a S4 N/A tranny in it and it revved fine.

staticguitar313

iTrader: (2)

gear ratio difference?

fast90rx7

Gear ratio wouldn't matter. It would just make the the engine redline at a different speed. It wouldn't stop power over a sertin RPM. Oh well I think im gona get this car, and put in a S4 n/a trans in it and see what happens.

Turbo7MN

Perhaps something got knocked loose during the tranny swap?

fast90rx7

possible. I will probably be getting this car in about 2 weeks. So Ill check everything out then. Oh he told me that the 6th port is wired open.

Turbo7MN

You're probably going to want to at least fix that then. Wiring the ports open will give you the same high-end power as a properly functioning system, but a lot less low-end.

Good luck with it.

-Darren

fast90rx7

yeah.. I just thought of it but ill ask the owner of the car if the car slows down reving at 6000 RPM with the clutch pressed in. If it slow down reving with teh clutch in that means that it couldn't have anything to do with the trans.

kontakt

talkin out of my *** here, but if there was a high RPM hesitation to the motor, maybe with the new tranny it can't quite make it past the hesitation in gear?

84stock

iTrader: (5)

I agree with either the 5/6 port issue, or there could be an issue with the secondary throttle plate choke butterfly sticking shut. I would make sure the prots are wired open, then wire the choke open as a test as well. Check for a clogged aire filter too.

fast90rx7

ok ok... new update.. I told the owner yesterday to rev the car up with the clutch down. It was late so he did it today. He told me that it still does it with the clutch down but not nearly as bad. So i asked him is it poping or anything out of the exhaust. He said no. He said it revved up quick to 6K and then slowed down after that. Just like I thought. It couldn't be the trans. He said when it is in gear it is alot worse, but Im pretty sure that is just because there is some strain on the motor. So do you guys still think it is a 5/6 port problem??