Easily said when you have had the power .



What sort of turbo/ set-up would give you 2,500rpm spool-up on a standard engine with 350bhp?

62 trim is not far off tbh

Superspool / GT28R / HybridS3

When I had my GT28R, it gave 300bhp on a poorly-mapped Unichip and it only spooled a bit later than standard, and this was six years ago, Recent developments in mapping and other supporting mods means it would probably be very close to standard spoolup points

You'd be very lucky to squeeze 350bhp from a Superspool but if your aim is 300bhp it's possible with supporting mods.

Yes - I've seen Leighton's Hall of Fame - the S3 Hybrid appears to be the weapon of choice, but the GT28R is very close

What we really need is for someone to work out how to run twin or sequential turbos

Twin probably wouldn't work, due to the odd number of cylinders, but sequential might be an option. Tiny little GT25 to give boost from 1,000rpm, which then gets taken over by a nice big GT2871 after 3,500rpm

What you want is a supercharger then running to a GT35 in a sequential manner(wastegate controlled supercharger obviously)

But in the real world what we need is for someone to develop a low cost high flow inlet manifold replacement, and some cams that are a far more realistic price than the C and B cams. That would move things up a bit...

Given the problems the RX7 boys have with the sequential turbo set-up and the fact that they all seem to 'switch off' the sequential thing ASAP, even opting for a big single, I wonder if it would be worth the bother effort.

I think a forged engine with decent headwork, ported bits, free-flowing exhaust and a GT28RS/ GT2871R would give the best compromise for a coop. Given the difficulty I'm having getting my mere 315-342bhp down in cold/ damp weather, I'd sruggle to justify spending for much more.

I'll be more than happy when I eventually get the exhaust side sorted with supporting mods (clutch, walbro, injectors etc).

I agree (that's pretty much my spec) - but I still don't think its the best return for the money

Spend one third as much for more than 75% of the performance

Remember Dave_t's car at Curborough in 2009? - fastest car there and it was running a standard turbo at standard boost. A sorted chassis is worth 100+bhp and it's a benefit all the time

Yes, but out on the road, pushing a car with a sorted chassis on a twisty road will get you into more trouble than a quick blat with loads of POOOWWWEEERRR. When there's a 997 911 Carrera S pushing you up the road, nothing but horses will do the job

It's hard to justify spending money on the handling if your car manages the power it makes...

Good point - I'd sooner have a 400bhp car with a sorted chassis that a 300bhp car with a sorted chassis.

However, if I was trying to build a quick Coupe on a limited budget, its cheaper to spend a grand on suspension and brakes to go quickly, than it is to spend three grand + on a forged engine build

IMHO, a 300bhp Coupe with a properly sorted chassis will be just as quick as a 400bhp Coupe on a stock chassis, unless its on a wide-open circuit, such as Silverstone. Round Cadwell, the bigger power car wouldn't see which way the lower-power car went.

I think the best compromise is a standard engine with a GT28R sized turbo and all the supporting bits, not going over about 320 bhp.

Perfect balance of spool up, power delivery, none of the boost map is wasted, every part feels perfectly matched and free flowing, and it's probably the best bang for buck level of upgrade before you need to open up the engine itself.

Mine just felt perfect at that spec and is still going stong today with it's new owner. If I had a couple of grand to spare I'd do the same with my LE but I really dont at the moment.

My sentiments exactly ^^

However, as we all know, there's no such thing as "enough power" and its difficult not to be on a constant quest to find more

Thankfully, I've reached an enforced limit on mine, which is preventing me going further. To go any further on mine, I'd need an even bigger turbo, which would result in a post-4,000rpm spoolup (unacceptable) and I'd also need a beefier clutch to handle it (again, unacceptable as the car is a daily driver in heavy traffic). Add to this, the law of diminishing return, and I'd probably find it would cost me a huge amount, just to get another 50bhp or so AND I'd make it less easy to live with

No-brainer to stay as I am, and concentrate on keeping it looking good

If anything, my next expense is a new exhaust to quieten it down a bit. I'm thinking twin 2.5" with an electric cut-out to use a fully silenced exhaust path when running less than about 1 bar (the other 2.5" path would be almost un-silenced - 2 x 2.5" is just a little bit bigger than 3", so I wouldn't loose any peak performance)

Not cheap though....

and ill sell you the bits to do it mate


build a beast

it may cost a lot,it may break gearbox's,it may cost a fortune in..petrol,oil,tyres,garage bills

but for those times when you are getting the power down and it is going well you will not want to be in a 300 bhp car or even 358 which my last one made...great car for a while

i am going to stick my neck right out and say its possible to build one that spools quick ,responds real quick and still makes real good power (thats not what i have built and i am not trying to say that) with some of the platforms and turbos now available i would say it's possible to do things in a slightly different way...theres lots of stuff out there on the internet for those that have the time or inclination..i have used some on mine that have not yet been tried and i know if ihad gone for slightly less i could have maybe built a better alrounder than has yet been done (with the help of the right engine builder)

whos going to be first with the axe ?

What can one add to the posts above...

Cheapest starting place is talk to Flea, Barbz, CountryCruising, MotorMech and rest of specialists on actual costs on what you want.

Genuine engine tuning is VERRRRY expensive..period.

So many post above state 'supporting mods' this is when the cost mounts ..believe me I have done it and you also need patience.


Bottom line = cost! Do you have the pennies..if so whats your top budget?

Spot on. The budget is all. Even a Stage 1 Flea map will show up any weaknesses in the rest of the car. When I bought the Scottie she needed a little tlc, especially as the exhaust fell off after three days. A wider stainless exhaust with race cat, uprated EBV and Stage 1 mapping showed that the clutch was on the way out, and my brakes now need replacing again. This little lot took care of £1.5K - without routine servicing/tyres, etc.. With Coupe prices the way they are at the moment you will NOT get this money back.

I still think it was worth it, and I am happy with my 270bhp. The next stage would mean hybrid turbo, FMIC and uprated clutch and brakes; another £2K there then!

Sharing same opinion, i'm planning to take that route.....

Indeed I more or less said this earlier. Any car will benefit this.

Definitely prefer the power graph of a standard 20vt with a good kick at around 2.7k over the tuned 'not really impressive until you're doing 3.5-4k revs'. In fact I still think my GTIR is a bit late at spinning up. I think I'll check it again, but must say I also rather like it in certain circumstances, and I also don't worry about the missus driving the car.

its definately possible now to get a 400 +bhp car with very close to standard spool by using a different tuning platform than has been used so far..using different turbos and bolt ons..it will cost a lot and will need be done from scratch but its possible ..i think there are a few suprises in store for coupe tuning this coming year...

im not an expert on coupes, but from my limited experience in tuning turbos on the a series engine lots of changes have happened in the hybrid turbo area.

where previous T3s were standard, now hybrid T1.5s are quick to spool and allow 20psi for a 1.3 lump to push out serious power.

Unless the coupe engine has other limitations then im sure quick spooling hybrid turbos are out there somewhere that fit the bill.

id be interested to hear views on specific turbo options for the coup

I would like to read Barbz opinion.

This is my ideal setup for 300ish:
Superspool
Race cat on stock exhaust.
ITG panel filter in OE box.
Forge 007 recirc DV.
Fuel pump wiring mod.
FC performance remap.
Spend the rest on decent brakes and suspension.

indeed there are other options than what seems to have been the norm so far not just with turbos but with the piston design ,headwork and other aspects of tuning..as i say i have used some on the car nearing completion in fact i havent really used anything that is normally used on the 400+ cars built so far

I'm just under 300 mark (291) with all the work done by Flea. Looking to getting a little more work done in the New Year. You are more than welcome to pop around mate and I will take you out for a ride When the roads clear up that is

to be honest ktm450exc im sick of hearing of what your going to do and of what you have done. can you not shut up for one minute about yourself

^^^ Don't be too surprised if your non-constructive post gets you an non-constructive reply.

Barbz - good to hear from you on the forum again and its great to see your recommendation. I know you're working on something with a few bhp but its great to see a strong recommendation to spend money on brakes and suspension, rather than chasing the big dyno numbers

The only other recommendation I'd make to anyone that's thinking of going much over 300bhp, is get some good headwork done - it will pay for itself over time.

I had a Barbz stage 3 head fitted in 2006. The actual fitting didn't cost me any more, as the engine was already in bits for forged pistons. However, let's say the whole thing was going to cost £1,500 (about a grand on the head, and £500 to fit) - here's my sums....

Fuel consumption pre-modding - 250 miles per tank
Fuel consumption post-modding - 300 miles per tank
Annual mileage = 30,000
Number of tanks for 30k miles pre-modding = 120
Number of tanks for 30k miles post-modding = 100
Number of tanks of fuel saved per year = 20
Cost saved = 20 x £65 = £1,300
Total value of fuel saved since fitting new head in 2006 = £5,200+

OK - you probably won't save as much money if you're only doing an average 15,000 miles a year, but its still VERY much a worthwhile mod

Also, my 300 mile estimate above is very conservative - I often get close to 350 miles and on a long run, I get over 400 miles, so my total fuel saving is even greater

Just think, for those that have a wife and/or GF to convince - this is a no-brainer....

Coopist
"I know it's £1,500 dear, but it will pay for itself in less than 2 years, and after that, we're actually MAKING money"

Wifey/GF
"Will it make it go faster"

Coopist
"well, yes, but that's not the reason I want to do it - I'm just being as ecologically-sound as I can - saving fuel is great for the planet you know..."

Bit harsh! Santa not bring you any pressies yesterday?

The hybrid s2/3 along with supporting mods can easily achieve that power. Defo worth the money as standard 220 is so slow!

merry christmas jonofitzer and a happy new year to you and yours

sorry folks as you now know there is history here

jonofitzer..just don't read the posts ...simple really..:D