eriksseven

iTrader: (6)

Info:

The car is the TII in my sig. Several months ago I rebuilt it (1st rebuild) after blowing an internal coolant seal. The car had 140k mi. and compression tested at around 90psi-85psi before blowing the seal.

Anyways, my first rebuild failed. I was letting it warm up outside as I brushed my teeth, when I came back out to drive off, it had died... It had 800mi. on it and had compression tested at around 90psi-90psi the day before. After it died, I tried to drive it and it couldn't hold an idle and it sounded strange. I pulled it into the garage and compression tested it. The #'s dropped to 75psi-90psi. I'm pretty sure one of my corner seals stuck in it's slot (or whatever you call it).

SO, I re-rebuilt using my N/A's 60k mi. housings and rotors (I gave everything a nice street-port too). I used the N/A rotors because I have a close friend who used the same rotors with good results, and because I'm pretty sure one of my original TII rotors was slightly bent at one of the corners.

I'm pretty stoked because on the first rebuild I had my friend helping me out, and this time I was able to figure it out on my own (woo hoo!)

Anyways, after an agonizing break-in that included no boost until 1000mi., I finally hit the 1000mi. mark!

On it's 'christening' run I went WOT in first gear to 4k rpms. I must say I wasn't too impressed, but then again it was only hitting 2psi of boost when I shifted... Pretty much, it doesn't pull very hard, but I'm keeping the rpm's below 4.5k.

Shifting at 4k in all gears, it hits 2psi of boost in first, 4psi in second, and around 5psi in third. Can anyone confirm if this is normal? The only performance oriented mods I have are a drop-in K&N filter, street-port and gutted cats. I also have a ported WG, as well as a greddy type-S BOV and RB FCD that I'll be installing tomorrow.

The compression tested at 92psi-90psi about 150mi. ago. I'm still having hot-start problems. About how long will it be before I'm getting full compression? My N/A tested at around 100psi all around before it failed and I'm using those good housings/rotors will all new Atkins seals...

How should I finish off my break-in? Is it pretty much safe to do this low RPM boosting for a couple hundred miles and then bring up the RPM's? Also, is it safe to be boosting with my relatively low compression?

Any tips/comments would be appreciated. I'm gonna go BOOST for a bit and I'll come back and check this thread later. yeaaaaaahhhh!!!!

Travisty

sweet, hope you dont blow it

kd86rx7

iTrader: (1)

i also have hot start problems with my rebuild, wat do i do?

eric.

ecyrb | SLC

Dude we need to take some fresh pics....... Words can't discribe how good it looks now.....

RETed

http://fc3spro.com/TECH/FAQ/breakin.html

Your boost levels are dependent on your max boost, and you don't tell us your mods (especially your exhaust).
5psi is low, but not unreasonable if you're using a restrictive exhaust system.


-Ted

kd86rx7

iTrader: (1)

i also have a question about my new rebuild sorry for stealing the thread, my car starts up everytime but once its hot or warmed up, i cant get it to turn over, i drive 1 mile from my hosue to the gas station and it wont turn on after taht, i have to push start it. after driving 25 miles, i couldnt crank it over either i had to push start it to make it turn on. is it because im flooding? i took out the egi fuse and crank a few times and still wont turn over. only thing that i did to make it turn on was push starting it. any suggestions?

eric

eriksseven

iTrader: (6)

^ I said in the 1st post that the only "performance oriented" mods are s4 N/A rotors, stock exhaust with gutted cats, K&N drop in filter and street-port. The compression tested at around 92psi-90psi about 200mi. ago.

So yeah, I'll read that article, but please get back to me (or anyone else) with any comments.

BTW, it's starting to feel pretty decent... Just about 5psi is the max boost I'm experiencing at around 4k in 2nd and 3rd gear.

JasonL

Yea that sounds about right, for boost. Just get a manual boost controller.

RotaryEvolution

iTrader: (30)

should be a little higher in the boost i would think with gutted cats but the stock mufflers are quite restrictive still. with S4 n/a rotors it should be boosting quicker than that however, you should see max boost earlier than 4K with those rotors.

as far as boosting, i still stick with my unconventional methods on my own engines. i started boosting my engine within a few miles of pulling out of my driveway after an overhaul, drove it 45 miles to our local RX7 club meet and drove it home. it now drives like it wants out of the engine bay. i had to install the muffler resitrictor to keep boost levels down but my engine is stage 2 ported, turbo ported, WG ported, 3" turboback and TID mods done so you can't compare mine but i have had no problems doing break ins on my engine this way. the engine has 1500 miles on it now and produces more power in it's life than it ever has.

eriksseven

iTrader: (6)

Yeah, I'm a bit interested in why I'm seeing relatively low boost levels...

Can someone explain again what the twin scroll deal does on the s4's? I was forced to replace the stock vac. lines with silicone hoses without knowing *exactly* where all of them needed to go (some broke on the 1st removal). Could something either in my WG or twin scroll be limiting my boost response etc.? It has (IMO) really weak throttle response and kind of picks up somewhat at around 4k RPM's. BUT, my judgement might be somewhat impaired because my friend just got an FD a couple weeks ago and it has really fast boost pickup. BUT, my OTHER friend who rebuilt using the same setup as me, HIS car feels amazingly fast...

I don't know... It's been a while since I've boosted in this particular TII (over a year), but my N/A had great throttle response.

RotaryEvolution

iTrader: (30)

if you have the twin scroll hooked up to the wrong vacuum line it could be staying closed causing your boosting issues. to check to see if this is the case, remove the vacuum line to the twin scroll and cap the rats nest side and leave the servo side open to the atmosphere and drive it.

personally, i gutted the twin scroll system and ported the turbo similar to a S5 setup when i did the wastegate porting, i'm happy i did.

eriksseven

iTrader: (6)

^ would this cause the twin scroll to be disabled (like, to find out what it feels like NOT working?), or is this a way to make it work?

thanks for the responses

RotaryEvolution

iTrader: (30)

pulling the vacuum line to the diaphragm causes the twin scroll flapper to stay in the open position as if it was never there but the flapper even in the open position does still block the flow a tiny bit. the twin scroll port on the turbo is smaller than the secondary port also which limits the turbos capacity somewhat.

eriksseven

iTrader: (6)

nice... Although, now after looking at in the daylight I think I plugged the vac. line into the right nipple. It's the little brass colored bell shaped deal with the nipple on the bottom, right around the BAC/ACV kind of on the backside of the block.

eriksseven

iTrader: (6)

BTW, it's hitting around 5psi in 2nd and 5psi+ in 3rd (but I'm trying to keep the boost from creeping too much)

I've got 1220mi. on it, I'm probably going to take it to redline at around 1500mi., but I'm worried about what I'll find up there...

I'm not sure, but I'm pretty sure my engine is going to start vibrating heinously like it used to do at 5k+ RPM's, back before I rebuilt it. I'm pretty sure it's gotta be bad grounding for the 2ndary injectors, but I really don't know...

RotaryEvolution

iTrader: (30)

was it like a bucking with intermittent power losses or more of like a vibration with power being normal?

eriksseven

iTrader: (6)

vibration with power being *somewhat* normal...

eriksseven

iTrader: (6)

It's interesting, when I pulled my motor the 1st time, we discovered a broken motor mount. So, I just kind of assumed "oh, it was the broken motor mount that was causing the shaking". But this of course ignored the fact that if it was only the motor mount, the shaking would be sporadic and all over the powerband (obviously getting worse in the upper RPM's)...

But, the shaking (at least in the past) would be little sections of the powerband... Like, from 5500 RPM's to 6k RPM's, then it would smooth out before shaking again at 7k RPM's... The shaking would also be worse the 'colder' my car was...

Although I don't assume the shaking will be as bad as it was in the past because I replaced the broken motor mount, it's still one of those big downers that make it really not fun to take my TII into the upper RPM's... If you have any idea what could be causing this, PLEASE hook a brotha' up, lol.

RotaryEvolution

iTrader: (30)

is it speed related or does it do it in neutral without moving?

eriksseven

iTrader: (6)

I'll have to find out for sure when it's a bit *safer* to rev that high, but before, it would do it in neutral as well as under load...

I assume it'll be the same with the rebuild.

RotaryEvolution

iTrader: (30)

quit being a ***** and go out and floor the bitch... seriously!


sorry for the dramatics but one thing i can't handle is people who baby their engines. 1k miles babying it is ok, i can deal with that but after that let it loose for pete's sake... if it can't handle a little abuse then i would chuck it, you had the engine apart so i doubt it is anything internal, if it is a tranny and it grenades, it was probably unrebuildable anyways and you can get them cheap just about anywhere and better to dump a tranny in your driveway than 40 miles from home.


the only things that can cause a vibration in a rotary engine are incorrect flywheel and/or counterweight or a mismatching set of rotors. only other things to consider are accessories. you can pull all the belts off and run it at those RPMs, if the vibration goes away then put the belts on one by one until it comes back, do not run the engine without a water pump belt on for more than 5 minutes. lastly, check your thermo fan for bearing play, rock the fan side to side in/out on each side to see if there is much free play and if it spins without any resistance indicating it is bad.

speed related vibrations would include, driveshaft out of balance or damaged, tires/wheels out of balance, bad u-joints in your driveshaft, worn steering/suspension components.