Hi guys,
Just curious what\'s the maximum bhp that can be expected from a set-up with stock twins? I\'m sure there are a fair few of us \'twins\' still about. What power have you achieved, and what have you added under the bonnet to get that extra power? I don\'t even want to entertain the idea of upgrading to a big single at the moment. I\'ve just spent a fair amount of money getting my twins re-built, so I\'d like to stay with a twin set-up for a while and get the use out of them.
This question has been prompted by an incident this evening where I was beaten by a Scoobie :eek: It was a close race, but ulitmately he inched past me, and when it came to shifting around a round-about on to the next stretch of the motorway I couldn\'t even stay close. God damn those things corner well!
No disrespect the driver or scoobies in general. I actually quite like scoobies, I probably would have got one if I never found out about RX7\'s.
Cheers
Jon
I thought FDs are supposed to be good going round corners.......
Take a look at my signature, thats what you can get. I have done a lot of mods and we did max out the stock twins.:cool :wave
Well done mate. :rollin
Warthog
What mods have you done to get that sort of power?
Tony it depends on what you want really..... You can have big power with the Twins as Warthog proved, I also had done exactly the same ;) , but then I want total reliablity and be able to rag the arse off it anytime.
Do hard track time and drive home after, day in day out and all with seriously good enough power!
No point ever maxing the twins or any Turbo for that matter as they won\'t last!
(too early to explain Turbo physics now)
But yes you can get some good power out those little things, providing you have all the other ingriedents to complete the flavour... :yes
I\'m guessing you need all the stuff that you need for a big single upgrade - uprated fuel pump, injectors, radiator to cope with the extra heat, and an ECU to deal with it all. Prob don\'t have to get an intercooler, but the stock one is pants, and there are a few out there that sit in the stock positioning which do a good job (And are a fair bit cheaper than a big FMIC)
Thanks for the comments guys ;)
QuoteOriginally posted by J.j.
I thought FDs are supposed to be good going round corners.......
True. Don\'t get me wrong, the handling on the Rex is awesome! But, RWD vs. AWD going round very tight bends - is there any contest? I thought scoobies were particularly good at handling because of the boxer engine giving the low centre of gravity - but that\'s just a guess?
QuoteOriginally posted by Warthog
Take a look at my signature
Very... VERY impressive mate! I guess you\'re proof that there\'s hope for us twins yet.
TRex - Although I\'d love the kinda stats that Warthog has, I think anything over 300bhp at the wheels (not the flywheel) would be very nice. Certainly enough to see off most scoobies? I would want to retain as much reliability out of the car as possible when increasing the power. So just a little bit of tweaking for now I think.
nikp - Appreciate what you\'re saying mate. Essentially I\'m looking at the same additional mods that you would have with a big single, but without the big single. I do like the idea of a FMIC (after seeing John Yorkes charge cooler at the recent Essex meet)... but I take it they\'re expensive though? What kind of bhp gains could you expect from a FMIC, or is it mainly about keeping engine temperatures down?
Cheers
Jon
I think you will find the Chargecooler costs less then a FMIC
This is probably the first time Im saying this.
totally agree with you TONY BLAIR.
;)
Hi,
I currently have stock twins on my FD.
Here\'s the spec...
Apexi power-FC ECU (mapped by reworx)
Downpipe
RE:worx cat out pipe
80mm Catback System
Apexi power intake kit
V-Mount intercooler/rad
mapped on shell optimax to 301.3BHP (RWHP) without an external boost controller.
I now have a Blitz boost controller so i can adjust things such as gain, and boost levels.
Not sure if that helps?
As yet I\'ve had the chance to race nothing.... everyone is always going the opposite way - lambo\'s, porsches, M3\'s..... or they don\'t want to play.
Dave
Thanks for the info Dave. Much appreciated. With regards to races... just cross the border into Essex, there will be an army of Novas and Corsas waiting for you. ;) You may even spot the odd Rex or two.
After reading these posts I think the 300 RWHP I\'m looking for is well within reach on my stock twins, which is ulitmately what I wanted to find out when starting this thread. Thanks for all the info guys. :wave
I\'m a bit confused about the difference between a charge cooler, intercooler and a FMIC... so I\'m going to do a little research on the differences and benefits.
All the best,
Jon
I\'m not entirely sure what a charge cooler is myself (I thought there was often misunderstanding as to what they are and n fact are the same as an intercooler - just naming of them different. Both cool the charge!!?:rolleyes: ).
However, FMIC is a Front Mount Intercool. Generally mounted in the bumper as far forward as possible to make use of as much cool/cold air as possible to reduce those charge temperatures. Standard intercool is rubbish, but uprated ones that fit in the stock position can work well as far as i understand.
My last Dyno on my stock twins was 317.8 ATW (or rather hubs). That was running only .7 bar. I\'m upgrading my whole fuel system on monday so I can get a bar out of it. I\'m hoping to be up to 350-370 at the wheels from there.
Current mods are Street port, 3" straight through exhaust and HKS downpipe. Apexi Induction kit, large SMIC, Power FC, Blitz SBC IDIII boost controller and a WGT map.
QuoteOriginally posted by Oedipus Rex
My last Dyno on my stock twins was 317.8 ATW (or rather hubs). That was running only .7 bar. I\'m upgrading my whole fuel system on monday so I can get a bar out of it. I\'m hoping to be up to 350-370 at the wheels from there.
Current mods are Street port, 3" straight through exhaust and HKS downpipe. Apexi Induction kit, large SMIC, Power FC, Blitz SBC IDIII boost controller and a WGT map.
What injectors are u upgrading to?
Pip told me I had to upgrade my injectors as well to raise more boost but not sure which one is best for price. I looked at the kg packages which cost around £380 but thats running 1600cc secondaries.
Is there any other alternative or cheaper option? I am only running on stock twins too?
I\'m going for the 1600 secondaries because I want to crank a bar of boost out of it. I know its pricey but compare it to putting a single in. And even if you do put a single in you\'re going to have to put some 1600 in anyhow
Where are u getting it from? Any recommended place (cheapest)?
I will probably have to get a set too. :p
Hi,
It can be confusing when you first get going, hopefully some of this will help.
1) Chargecoolers work using water or ice to cool the air charge i.e. they are a air to water cooler and usually have a separate rad to cool the water. For short blasts they offer more cooling and they don\'t require airflow to cool the intake air. Essentially they are good for applications prone to heat soak or for short drag style runs.
2) There are a variety of intercoolers (air to air coolers) available for the RX-7. These range from:
SMIC - stock mount intercooler - these mount in the stock position and are usually larger than std. They fit nicely with stock components but don\'t generally offer massive gains.
FMIC - very very very good at cooling air but a trade off it the fact that it sits in front of the rad and hence you get heat soak at low speeds and may see increased rad temps as a result.
V-Mount - the rad and IC fit in a V so that both get good airflow. The IC doesn\'t get as much as in a FMIC position but should see a car that has to do daily or stop start hauls through slightly better.
It\'s everyones opionion at the end of the day so other people may have a different view.
Don\'t be too confused you should be able to achieve the 300RWHP you are looking for on the twins, just make sure you do it sensibly.
As for scoobies, I used to have on before the RX and I have to say corner for corner the average driver is going to be faster in scooby as they handle very very well with min effort from the driver. However, the RX in the right hands will kill any WRX... i\'ve yet to race one... (not that i\'m the right hands by any stretch)
As for essex - i get enough shatso\'s and corsa\'s trying to race me in London but I want to race something interesting... I\'ve seen and driven enough modified "chav" cars to know they aren\'t usually worth the time to race. Plus they usually try and race you in an area where you are likely to cause an accident which is just stupid. I welcome them to bring it to the track any time.
So my next point is that I am slightly confused....
"I\'m going for 1600 secondaries as I want to crank a bar of boost out of it".
I run .98 KG/CM2 on my car with my current setup and have more of a problem with overfueling than underfueling (.98 is just under 1 bar)
Strange but I guess every car is different.
Dave
I think you hit the nail on the head with the every car is different point. There are so many factors determining how much fuel you have. Because of my mods, my bar of boost should be getting me around 350 at the hubs, so shes generating a fair amount of power there and very thirsty for the fuel.
Excellent write up about intercoolers, charge coolers etc. Nice one mate ;)
I know what you mean about chavmobils... They know they\'ll get beaten in every scenario so they take stupid risks to try and get in front on you. I often just let them go... I\'m not interested in racing around the town centre AT ALL!! It\'s just ridiculous, so many potential accidents - too many cars pulling out of side roads, or small children running out between cars.
All the best,
Jon
The new Scoob and Evos are very quick at accelarating and in the corners too! They tend to loose out in the top speed department to standard FDs.
But when you look at how much they cost and how new they are compared to an FD, we can\'t complain!:D
Yup i agree with you there.
Scoobies are just too common for me - they are really nice but the new ones tend to be driven by people (at\'s not all of them but most) who have no clue about what there car is or how it works...
Now personally i\'d like a go at an R34 or 911 Turbo.
WARTHOG.
1994 RX-7 FD3S.
Street Ported HURLEY engine with 3mm Racing Tips, running Stock Twins, HKS Exhaust with FEED de-cat mid-box, HKS Induction kit, APEXI ecu + commander, Bosch 044 Fuel Pump, 1300cc Secondary Injectors, GREDDY Pulley Kit, PWR Radiator, PWR Charge Cooler Kit, Plugs 2x10’s and 2x11’s, Magnecor 10mm ignition leads, GREDDY Boost controller, Blitz Turbo Timer, XTREME Single Plate Clutch DSB_XHD, Lightened Flywheel and counter balance, RE:WORX Diff Brace, RE:WORX Gearbox Brace, RE:WORX Swirl-Pot, RE:WORX Water Injection Kit, FEED Engine Brace, B&M Short Shift Gear Stick, TEIN Adjustable Suspension, Front 235/40/ZR18, Rear 265/35/ZR18 Dunlop Super Sport Race Tyres.
That\'s quite a shopping list mate. :eek: What\'s a swirl-pot by the way? Sounds a bit magical. ;)
QuoteOriginally posted by TonyBlair
That\'s quite a shopping list mate. :eek: What\'s a swirl-pot by the way? Sounds a bit magical. ;)
It\'s how you predict the future and tell peoples fortunes after you\'ve drunk your pot of tea and "swirled" the leaves around a little bit! :rollin ;)
Very magical indeed,
Paul:p
It ensures that you don\'t get air being sucked through into the fuel pump. You do need it when you upgrade your fuel pump. It stops detination due to air in the fuel. Some people have got away without it by ensuring they always have 1/3 tank of fuel. But whats the point in trusting to luck when you can prevent it. Also ensures your fuel pressure from the tank, very much a must if you are going to be doing any real track time. HTH.:wave
I\'m off to work now. I will try and post my views and first hand knowledge of Charge Coolers later, for your info.:wave
Most of the Charge cooler writeup is correct i would add though they do work very well over a long period of \'sustaind boooost\' prior to fitting WI [- which is a must if you are looking for VERY big power out of twins =320atw] I would see intake temps of C30 -35- that was running 1bar on twins with 317atw
The charge cooler is a very inexpensive alternative to the FMIC, the install is a lot less expensive, the cost of buying is less, it does not rely on cold air to cool it [hard to find in summer!] The other problem with FMIC is if they are not installed with the consideration of allowing sufficient cooling throgh to the water rad you will experience overheating [engine wise] which is very bad [consider the rotary as a very hot running engine as standard - if you put more boooost through you generate more heat which has to be dispelled - stick a great big FMIC in front of the water rad - you have the added problem of high water temps.], you need when modifiying to consider all angles not just getting more power from the engine but is this [or that] mod going to have a knock on affect?
Once you have this all powerfull engine you then find stopping the beast is a problem - traction is next - getting it around a corner faster.................................... they go on and on:confused:
I know nothing about this! but does it follow that a charge cooler will cause less Lag than a FMIC? and have quicker throttle response?
Just as a matter of interest, Bob
RO284 in answer to your question YES. The c/c is so much closer to the turbos and plunum the air flow is more direct. The 2nd turbo comes in that quick it\'s a matter of what turbo lag.
John York has covered most things, the only thing i will add is that if you are going to go for big bhp on twins then i am just going to experiment with removing the air-con rad and drop in my old engine rad with a couple of fans on it to use as my cooling rad within the system. The reason for this is that putting so much boost through the twins heats them up a lot and my intake temps are suffering a bit 45c under continued high boost runs.
I do have a number of options open to me 1. as above . 2. i have not as yet sorted out cold ram air to my aopexi\'s but i will before RS11. 3. I am working on a idea to scoop cold air from under the car to blow over the twins to assist with cooling them.
John is spot on when he says you just can\'t go for big bhp and think everthing else will be fine, you have to balance everthing. To each force there is an equal and opposite force. Make more power=make more heat=make more cooling to reduce that heat.
As we have now maxed these twins out i can now work out how to gain more power by doing more cooling. I will eventually get to the point where i am happy and have reached the targets that i have set for myself and the car. At that point depending on how well i can control turbo heat i may well put a set of the biggest twins i can fit in the engine bay or just go very big single. I havn\'t got to where i want to be yet, so i will cross that bridge when i come to it.
Anyway enough of me whittering any Q & A\'s you have feel free to ask and if you want pics etc then they can be supplied. I will be at RS11 so feel free to say hello and you can have a good look at the engine etc and take what ever pics you may wish yourself.
Good Luck in your search for what makes the car feel right to you.:wave :wave :wave :wave :wave
I wouldn\'t 100% agree with the chargecooler write up above. They are very good but both the cc and IC options have pro\'s and cons nothing is a free situation.
With a CC if you are cooling the water using the engine water and rad you aren\'t going to get a great deal of performance, this is the first big no-no when using a CC. The CC system should be separate, that means a separate RAD, water pump, header/ice tank and cooler core. By the time you have all that made and fitted it\'s going to cost in the region of a FMIC setup if not more. BUT it will offer very good performance as it can cool effectively in more extreme conditions and works well over a variety of environemental variables.
We ran a CC on our dragster with some good sucess and it performed much better than an IC arrangement on the strip. I would imagine on the street the performance would also be generally better assuming you use a separate setup. However you\'d be fitting in another rad/header tank and lots pipe work, making the engine bay untidy and quite tight.
The IC on the other hand simplifies the fitting, but won\'t offer the best performance. Once you have good airflow you\'ll see good cooling performance but unlike the charge cooler it\'ll force intake temps up when you are sitting in traffic and in general day to day operation it won\'t work as efficiently. But that\'s the trade off between the ease of fitment/cost/compexity of the two systems.
On my V-Mount I see average night time intake temps of around 21-23 degrees C. On a sunny London traffic day it\'ll hit 40 in traffic and drop to 30 in a light cruise. On a cold night it\'s been down around 10 degrees.
Hopefully it\'ll get cooler once the ally work is done in the engine bay.
I\'m not saying anyone is wrong here but I\'m trying to give a balanced perspective - both solutions are good and it again depends on the car and purpose as to which is the best route for you.
Spot on answer Monkey! :yes
(ro284) forget Lag with inter/charge coolers as this again is another story! Set up right there is no \'lag\' or what you may call lag in a good system with the right matched applications!
Monkey fd3, i think you have a misconception of the PWR Charge Cooler kit. The cost of it all is still way below a fmic and easy to fit. ( What i am talking about doing is enlarging my total water volume by using my old mazda rad in the same place as the air-con rad with a twin fan set up to cool the water return flow even better ) It is a self contained system is has nothing to do with the engine cooling system it is standalone. The c/c tank sits in the engine bay where the stock intercooler would be, it has it\'s own radiator that sits in front of the aircon rad with it\'s own electric pump and electric fan. The rad is only 13" square. John York because he has a single turbo does not produce as much turbo heat as the twins and his temps intake temps are very low.
My own engine temps don\'t go above 90c even after multi-boosts, they sit at about 85c everyday driving. The controls of the fan and pump are on switch relays not through the Apexi PFC. I not claiming that the c/c is the best thing but for the mods i have done and the power i have gained it was the best way for me.:wave
Ah you see I wasn\'t aware there was a ready made kit available off the shelf. Out of interest how much does that come in at?
Surely putting another rad infront of the AC rad which is in turn in front of the main rad could cause a problem in slow moving taffic.
I\'ve had a look around the net and can\'t really find much about them... have you got some more info
So you already have the charge cooler kit?
what water temps do you see on the CC circuit after an hour or so of running and what are the intake temps like?
I used to a run a cc on my scooby but wasn\'t really that impressed, I fitted an IC but before I could really asses the perfromance some tit\'s stole the car :(
I\'ve run a CC for over a year now in line with all the other mods and my intake temps under normal conditions are 30 -35 against FMIC temps of 25- 30 the trade off is worth it because of the free flow of air around your engine rad thus keeping lower water temps.
PWR make a kit to fit the FD, Pace engineering can make a bespoke kit. I plumped for the PWR because it is a very tidy kit and works very well. REworx are uk suppliers or you can try buying one from Aus. Pace have a web site [do a google search]
If you are at RS you are welcome to have a look ;)
My normal running intake temps on the apexi show 35-39. The reason for the difference between my temps and John YORKs will be the extra heat soak generated by the twins.( John runs a very big Turbo which therefore has a lot less crap around it and air flow can cool it very quickly ) I need to get a vented bonnet and work out a ram air system for the twin air intakes. As john has said it\'s about trade offs. My engine temps are fantastic, it\'s just me wanting to get as low as possible with intake temps. I understand that the standard intake temps with a stock intercooler are around the 65c mark--can anyone comment on this?????:wave
Are we taking the intake temp from the Apexi read out or a separate gauge?
As i said before with my V-Mount i see air temps of 27-28 degrees when i am moving, stationary it\'s around 40 on a hot day.
mr front mount on the move is about 25-30deg but stay stationary for a few mins and it soon creep up.water on the move is about 88-89 but will quickly rise to 94 when stationary when fans will then cut in...fr road use i wld def say charge cooler s much better it keeps water temp lower due no big intercooler in the way and is ideal for blatting down the road with comp temp to a intercooler.only benefit i can see with intercooler is if u suffer a electric water pump failure on c/cooler and dont notice it ur intake wld leap very quickly.if i was re doing my aproach i wld go charge cooler all the way
Ref the point about Pump failure, thats what happened to me. I always have the four view option on my PFC and can see at a glance my temps so you notice it immediately. The pump didn\'t fail completely it was working slow due to a faulty eletrical connection design fault, not my fault. But Geoff just sent me a new one next day delivery and in 10mins it was fixed.:cool
Thats what i call after sales back-up, no messing around. Not the customers fault, give him a new one and we will sort the company out. You can\'t ask for better, thanks RE:WORX.:wave
I really like Geoff and the guys down at reworx they fitted my IC and did the mapping work. Explained everything really well and were very helpful when I kept changing the date I was bringing the car in.