Right, I am considering going singe, i have done most of the supporting mods, what I\'d like to know is how well does a single turbo work with a stock engine, I will port it when it goes but for the time being I don\'t want to have to.
Also what turbo\'s are gonna work best with a stock engine, I\'m making 300 rwhp at the moment on twins
Alan
I\'m running a A-spec GT3574 with a 0.84A/R. Making a little bit more than what I acheived with the twins with plenty more to come. I\'m running a stock ported motor and it is seriously smooth and quick. Works out at 325bhp at the hubs at 0.94. Good Spool is about 3 - 3.5k rpm for 0.90 bar. Engine bay is very sparse in comparsion and you get rid of a great deal of the issues with the stock twin.
A conversion isn\'t cheap. You could easily add 1k to the cost of a kit in the bits they don\'t add in even if you do all the work yourself.
I\'m still learning to like it. Yes it is quick, very quick but the smoothness just makes it mask the sheer grunt. Definitely a good idea for a track car where there isn\'t a super snap when it comes into boost.
Would highly recommend one for sure :D
Shaun
How much was the kit Shaun if you dont mind me asking ? Also is it the
a-spec in the US ? My folks were out there and popped in, they gave them a tour of the place and were very friendly to them !!!
Right, that sounds good what isn\'t cheap though, what would I need to add in?
It is still quite different to the twins though. The twins definately build boost earlier on, so you have to work the engine slightly harder on a single setup. Whereas you could boot it very low down the rev range on a twin setup, you have to think about your gear selection a bit more due to the power being high up in the rev range.
There is a lot to be said for the twin turbo setup!
Hi
I have always wondered if a decent twin set up like mine producing around 350BHP is more fun as a street car then a 400BHP or just over on a single turbo set up. I have my 0.92 boost ready to come in any time really but a single turbo you are taking about 4k RPM and above. Here in London you would need a drag strip to really benefit form a single turbo I think but I could be completely wrong. I have never driven a single turbo and I am in a process of buying an additional RX7 to what I have ATM
Regards,
Michaelb
I bought it on a Christmas special. Worked out about £2100 with postage and Duty. Had the manifold coated and some extras to enable me to plumb the wastegate back into the downpipe. I then had the turbo and downpipe ceramic coated over here, had to swap to a smaller wastegate spring (partly due to fueling). You would need a blow off valve, a boost controller, new hard pipes, decent size intercooler, decent size rad (I still have stock) and good amount of fueling. I\'ve also got a ignition amp, racing plugs, uprated clutch, diff brace etc (list goes on)
I\'d love to do a drag against a twin without anybody building boost on the line to see just what the difference really is. The small single turbo is super smooth and very deceptive.
LoL I can tell you the difference. My 470whp VS my friends full bolt on TT that I had just finished tuning to 15psi 325rwhp. Both cars on 15psi with a passanger each from a standing start. whp difference is 145whp
We both launch hard, window open all I hear is wheel spin. Im straight spining hes sideways. Its even as we both spin through 1st gear, we hook 2nd & again we both spin then gain traction, His bumper is at the rear of my door, we hook 3rd & its still even the road is starting to come to an end. 3rd is moving through the rev range & I start to pull away. we shut down & run again the other way. He launched to hard & I left him behind.
TT FDs are faarken quick down low. Once max power & Tq are reached in the higher revs & gears the extra 145whp & Tq on the single starts to pull away. He would not race me on the high way. Stay tuned for the vid of me VS my brothers T61 Supra..when it gets out of the shop.
As you asked before about around town driving with a single, yes you need to drop gears for that out right power band but with the right turbo its very very fun & much less hassle than TT maintanance. We own 2 FD\'s. My girl friends FD is TT with 290rwhp & 13psi. We drive it often but Id much rather drive my car on its street tune. Yes I need the lower gears to keep in the power band of the turbo but hell its faarken insane when you step on it. I use a Garret GT3582R with 1.06AR. It spools from 2k & cracks full boost at 4k very very quickly thanks to the light weight flywheel & ball bearings. Boost setting dose not matter 15 or 20 psi it still gets there very quickley & dose not stop pulling all the way to 8k. I would not go back to TT as the single suites my driving style.
Is that with a stock porting though ? Don\'t get me wrong the single is for sure a lot of fun and does seem to drink way less juice off boost than the twins (don\'t jump into full boost as fast). The sheer early grunt of a well setup twin is alot of fun. The sheer grunt of a single on song is awe inspiring.
Shaun
Quote from: Dr-Rotor;520529LoL I can tell you the difference. My 470whp... I use a Garret GT3582R with 1.06AR. It spools from 2k & cracks full boost at 4k
don\'t spose you do the mapping on the datalogit fc? If so, don\'t spose you fancy sharing your map for me to have a gander at? :D
Sure do. Iv done about 10 TT FD\'s so far. I have a few maps. I did not tune my FD as I was not clued up on the tuning back then. The creator of FC-Datalogit himself MR Steve Rossan tuned my monster for me. Soon after that I began tuning the Apexi cars for my Rotary mechanic RX7HEAVEN. He builds some monster rotary engines.
Im still yet to post some pics of the work shop & the nasty PP single turbo he just recently did.
I take it your looking for a TT map? I tune differently to Steve. He sets the AFR map all on 1 & tuned from the base map. I leave the base map as is & tune via the AFR & timing maps.
I will email you the TT map of the FD that I raced if you like? Just give me your email.
O and to answer the other guys question, NO the cars are both on Extended port motors. I still get great fuel milage from my car. 450km around town & 600km on the open road.
Quote from: nikp;520572don\'t spose you do the mapping on the datalogit fc? If so, don\'t spose you fancy sharing your map for me to have a gander at? :D
You after my GT3582R map?
Maybe :D Just as a learning tool really. I am trying to learn to map, so the more exposure i get, the better
you could buy some BNR\'s for the less / about the cost of a single, and get all the benefits of a twin setup and the power of a good single.
Quote from: nikp;520617Maybe :D Just as a learning tool really. I am trying to learn to map, so the more exposure i get, the better
Yea sure...I dont mind at all. Email me.
bmlove777@hotmail.com
My cars map is not how I tune though. I will give you some TT maps to show you the difference.
Its not to difficult once you have it all setup with the right watches and the graph so you can record the runs & then go back and see whats going on at a specific rev or boost.
The graph is great. It shows where boost comes on & drops off or spikes. Also as you record & save you can use the slider on the graph to move along to the problem spot & it will corrispond to all the maps with a little black box that moves over the numbers that the maps is reading. So if you are rich at say 5k then you decrease the AFR number in the map where the black box has traveled over. Decreasing the number takes fuel out as dose increasing it puts fuel in. The number is not an AFR number like 11.3 or 12 or 14. Its a specific value pertaining to the conversion of the AFR for computer perpouses. So EG: 11.3 would be something like 1.325. You can see this by selecting the AFR option & it will change all the values to a rough estimate of what the AFR might be.
Its fairly simple once you have all the right screens setup to record what you need to see. EG: Boost, revs, duty, Air & so on.
The reason I tune via AFR is because Apexi designed the base map as a BASE. That is what it is. I have retuned a TT FD that was tuned via the actual Apexi tuning program not Datalogit. So the whole base map was changed but the AFR map was as it is from new. The car made 220wkw on a hub dyno. It came to our shop for a power run to compar dyno readings. It did 205wkw on a dyno dynamics. Fair enough result from 2 different dynos. They are only tuning tool. So the customer asked us to retune the car. So I started from scratch & put a stock new PFC map in. We tuned it to 240wkw my way of tuning. 15psi & 95% duty cycle. He wanted it maxed out so we did. He is going to put in a big fuel pump & injectors with reg soon for another tune to 18psi. Anyway he said its never driven so smoothly before & he can now brake traction in 3rd gear. Mind you he is very hard on the car when it comes to changing gears. This is the TT FD that I raced from a stand still...It is very leathel...keeps up well from a standing wheel spin start with my car.
Yeah, i have little problem with the fueling to be honest. It\'s pretty simple and straight forward for that bit. I am currently in the stages of installing a wide band lambda sensor.
It\'s the ignition timing that gets me. I\'m not very clued up on when, and by how much ignition should be advanced or retarded. Then there\'s all those other fields that can \'tweak\' your injectors (For example, sometimes it\'s a bit jerky if i come off throttle quickly or go back on throttle quickly - bucks about a bit). It\'s those bits and pieces that I am still learning and trying to figure out!
And thanks for the advice!
Sure no worrys. Timing is easy. In the higher revs you want to have a closer split EG: if the IGL is 10deg then put the IGT on 2 or 3 to get an 8 to 7 deg split. Tuned a car last night that liked it on a 6 split with IGL on 10 & IGT on 4. Put down 214rwkw or 284rwhp on 12psi or 0.8bar. Dont advance timing to much, thats when you start killing things. Takes a little getting used to, the rotary mechanic I tune for taught me everything I know.
Basicaly you close the split on high revs because you almsot need to have both plugs fireing at nearly the same time to keep up with the RPM of the Rotor even though its only doing 2666rpm when the cranks doing 8000rpm. Lovely how that works aye.
Thanks, great advice! Oh, the questions, the questions!
Just ask, Im no expert but I will try to help.
You sound like an expert to me!
LOL....not realy. I learn all I can. Iv only studyed rotarys. Iv never been interested in piston engines...I still dont know how they use all those parts to work.
The country I grew up in never had rotarys & I was always more interested in helicopters anyway & jet engines. I hated cars. Then I moved to New Zealand & saw the RX7 for the first time. I just had to find out what a rotary was. Once I did there was no looking back. I bought my first RX7 when I was 21...its my first car. Even my girl friend has one now. We dont drive anything els.