Chaps,
I might be coming back to the world of Rx7\'s soon. I had one a year ago or so, the engine went pop and I performed an engine swap at the side of the road. :)
I then sold it, had a GTO, Skyline, Supra TT.
The car I might be getting has the following spec list :
Engine:
13b-REW Engine (3000 ish miles)
HKS Twin Air Filters
Air Pump Removed
Blitz Dump Valve
APL Intercooler
Aeromotive FPR
Walbro Fuel Pump
4 x 850cc Denso Injectors
Full Non Sequential Turbo Conversion
HKS Downpipe
Re-Amemiya Centre Section
Racing Beat Back Box
Apexi Power FC Commander
Just curious as to what the above should be putting out at the moment as it\'s running on stock turbos.
Also wondering what I could get out of it with the currecnt injectors etc if I were to go single turbo?
Am I right in thinking all I would need is turbo/manifold remap to go single?
Try and have a look at this calculator:
http://rx7.com/cgi-local/3rdgencalc.cgi
Apparently the very limit on stock twins is about 400ish, knightsport twins apparently push more than that, but don\'t quote me, im an FC guy :)
Cheers.
So what\'s the most I could get from going single without porting the engine etc? The engine has not long been rebuilt, 3K miles ago. Don\'t think any porting was done at the time.
Hmm well without porting the engine, a larger turbo might take a while to spool, perhaps its best to run on stock twins as they are matched to the stock porting and perhaps upgrade the injectors, fuel map and fuel system?
I\'d GUESS 360-370. I\'m running just over 340 on a similar setup but maxing out the stock injectors pretty much. (well. 93% peak!) on sequential with stock ports.
It\'s the fuelling that\'s holding me back at the mo.
To go single you need the following. Turbo, Waste gate, New down pipe, New clutch, New manifold and a re-tune.
Stock ports with the injectors you have you can get around 350whp - 400whp depending on the turbo.
You will need a new clutch as the added power will eat the stock one.
id rekon about 360atf bud, mine was 350 at 0.8bar on stock fueling with similar mods
360 atf, not too bad.
How much does it hold it back by not having a ported engine? What would you notice if using a larger turbo on a non ported engine?
Tbh, I\'d probably only really go for about 450 to 500bhp atf max. Is this possible/useable on stock ports?
dont think 500 fly is possible on stock ports mate. i`d say 420fly or there abouts!!!
Iss there any porting work you can do to aid things without taking the engine apart? (seeing as it\'s not long been rebuilt)
Quote from: skybusr34;529659dont think 500 fly is possible on stock ports mate. i`d say 420fly or there abouts!!!
not strictly true, if you put a big enough turbo and run lots of boost you can do it, it will take ages to spool though lol
Porting helps to spool big turbos and a lot earlier, moves the peak power up the rev range and the power scope is bigger
Quote from: Jim_rx7;530857Iss there any porting work you can do to aid things without taking the engine apart? (seeing as it\'s not long been rebuilt)
no it needs to come apart to port the plates
with your mods on twins depending on tune about 300rwhp 360 flywheel, you can get more with water injection if you tune with it, putting a single on at 1 BAR will probably net you around 340 at the wheels at 1 BAR or just over, but each car/engine is different, some will get more some will get less
id say the to4e is the best all round turbo for a non ported engine and should see between 350-380bhp
350 to 380 atw, or fly?
fly I\'d say.
Best I would say is about 280atw. Best I got out of my stock twins was 320atw with stock ports at 1bar of boost. Some heavy mods on air cooling too.
Gone Single and havn\'t really seen a huge increase but only a smallish turbo. Blitz How much would I get out of my GT3574 if I pushed the boost upto 1.4 bar ?
Shaun
you are on stock ports Shaun? Max with the same sort of turbo as yours on his silver car got 380atw at 0.9 BAR on a street port.
You can run your turbo up 1.2 more then that I would run Water, 1.2 BAR I reckon you will get 360-370 atw
Yep stock ports. Been looking at the smart coolingmist dual system. I\'d need some more fueling too :Giggle
Turbo\'s only a 0.84 to get earlier spool.
Cool, Rx7club says the GT3574 comes alive after 20psi !
Shaun
So unless I get the thing ported, then I might as well stay with the twins? Not much point in going single with stock ports?
How much would it cost to get ported? The engine\'s only been rebuilt about 2500miles ago so nothing would need replaced apart from water seals etc.
Anyone got a rough idea? Seems a bit mad taking an engine apart not long after being rebuilt though. I\'m after a rough price if anyone has any ideas?
Going single is way more reliable at higher power levels. The turbos just blow hotter air after 0.9 to 1.0bar. They don\'t always last too long either. The initial feel of a twin setup has more grunt low down but the smoothness of a single is amazing. Would give huge amounts of confidence on a trackday and on the road.
Shaun
Cool... think I will go single then.
When the engine needs rebuilt or if it dies for any reason, then I\'ll strip it and get porting work done.
Just seems a shame to rip apart a fine working engine on very low mileage at the moment.
just buy a humped rex already converted n get it rebuilt lol, or even single rexs now are selling for peanuts :(
Quote from: Jim_rx7;531261Cool... think I will go single then.
When the engine needs rebuilt or if it dies for any reason, then I\'ll strip it and get porting work done.
Just seems a shame to rip apart a fine working engine on very low mileage at the moment.
yep just go for the GT35 like Shaun and when it goes pop eventually in a couple of years depending on use then get it ported
You could buy a blown engine, get it rebuilt (most of the cost is labour getting the engine out of the car) then port that engine, install the single turbo, swap the 2 engines over and sell the working stock engine, there are loads of people who just go the route of buying a working engine out of another car cause its cheaper than getting their own rebuilt eg Profs new engine :)
How much does a 2nd hand FD engine go for nowadays ?
Shaun
I sold my last blown one for £300
The car in its current setup was dyno\'d at 326bhp atw. What\'s that atf?
about 385bhp at the flywheel
Shaun