Realistic power estimations (goal: 160-170bhp)

[LeonL]

I've seen a lot of topics with a lot of different bhp claims but with no proof so after a little clarification on what exactly I'd need to achieve 160-170bhp

My list of mods (now and future) are as follows

Standard head
Standard bottom end
Standard g40 intercooler
Stage 4 Jabbasport charger
Psd toothed pulleys
Jabbasport induction kit
Boost return mod
Gt inlet
51mm tb
Ppp manifold and exhaust system

Once all done I'll ever get a chip or remap with yoof/ppp

So what's a realistic power figure here? And what more can be done to achieve the 160-170bhp goal, is rather avoid messing about with bottom ends and cams atm

Many thanks

[JoeH]

Definitely reckon at least 130bhp, but probably not 150bhp - not without head work.

I reckon around 140 with that spec!

The main problem you'll have is putting the power down, probably need subframe and quaife diff and good tyres which will cost more than engine mods!

[Jester]

Mine is similar spec to yours apart from I've returned to the standard airbox, GT inlet is ported and I have a Schrick cam in. I have RR'd print out's of 153bhp/158bhp (from different places and times)

So not sure,.. but I can't imagine why you'd need so much unless you're on a track or drag strip?

[LeonL]

Mine is similar spec to yours apart from I've returned to the standard airbox, GT inlet is ported and I have a Schrick cam in. I have RR'd print out's of 153bhp/158bhp (from different places and times)

So not sure,.. but I can't imagine why you'd need so much unless you're on a track or drag strip?

For what reason did you return to the standard air box

Also it's going to be used on track

[Jester]

I bought it with the jabba kit on and never really liked it visually. Also this might seem weird but it gave it a bit of an odd noise like a low drone, can't explain it 
(My brother got his with the jabba pipe/cone or K&N type and his made the same noise)

Haven't noticed the performance difference, can't imagine it's alot?. It might be worth looking into going Turbo if using it on track.

[LeonL]

Would adding 250cc injectors and aftermarket cam take me over the 150-160bhp mark

[hayesey]

the spec you listed sounds quite similar to mine about 12 years ago when it was rolling roaded at 141bhp except mine had the standard exhaust manifold and standard throttle body, so you might get a bit more.  You've not said what size pulley you're going to use, I assume 65mm (which is what mine had, was the standard size with PSD toothed belt kits). 

You might see 150 with a custom-remap, using an off the shelf chip will always be a compromise.

[LeonL]

Sorry yes 65mm

[JoeH]

Other potential ways to get more power without opening engine are:

- Stage 5 or full blend or R1 supercharger slightly more porting than a stage 4...maybe not much in it though.
- Run smaller pulley - but not advised for lots of miles (like 58mm)
- Buy a G45 charger, or G60 (extra effort needed to fit it)
- A vernier pulley on the cam shaft - but then yours is standard so may not do to much.
- Ensure stuff is port matched, T peice on TB is ported, Outlet on charger ported (they aren't always)
- consistently run high octane petrol

I would run paper filter to help protect the supercharger from dirt ingress.

I'm sure a lary Cam and remap and injectors may well get you to 150bhp

[LeonL]

As in air box and filter instead of the jabba sport induction kit?

[polo classic]

Here's what mine needed to get to 168,9

Jabbasport head
Standard bottom end
Standard g40 intercooler
full blend charger
65 mm pulleys
Jabbasport induction kit
Ported Gt inlet
49,5mm tb port matched to manifold
Supersprint manifold, race cat and Remus exhaust system
Custom Jabbasport map
Custom Newman 264/270 cam
G60 injectors

[Jezza-7]

I ran 171bhp which was done at aldon rolling road, 3 years after it made 170bhp so i'd say its very accurate. I see its only 2bhp more than polo classic above but every rolling road is different and not always as accurate. 7 years ago when i made 150bhp on one rolling road, 2 weeks later went to a charity rolling road day and it made 191bhp so its hard to tell what people actually make. Personally i find the power above seems a little high with a standard block. Best way to see what power you have is 1/4 mile. I managed a 13.3 on drag slicks, 14.2 on road tyres, i could of got better times but its pointless using road tyres on a track like santa pod. At my local drag event i ran the same time on road tyres and the surface is crap.

My spec was

1341cc with standard compression
ported head
Schrick 272 cam
GT inlet
51mm tb
custom made intercooler (slightly bigger than standard and fit in same place)
PPP manifold
custom exhaust
65mm german toothies
250cc injectors
boost retrun mod
R1 spec charger
PPP remap

[Jezza-7]

Don't forget PPP are not mapping currently.

[LeonL]

Standard head
Standard bottom end
Standard g40 intercooler
Standard exhaust system
Stage 4 Jabbasport charger
Psd toothed pulleys
Jabbasport induction kit
Boost return mod
Gt inlet
51mm tb

With the above modifications would it be worth fitting g60 injectors and a ppp g60 injector chip or would this be a waste of time?