2.5 / 2.6 L conversion advice wanted.

[caterpillar]

the audi 2,2 liter does have 81,00 bore, and the diesel 2,5 tdi does have 81,00 too and the 2,4 5pot have 79,5 bore...the syl thicknes are with the org bore..
in the smokie yunic ( power secrets) he said minimum bore sylinder thicknes are 3,3mm.. BUT the volvopeople with the b23 and 230 does rebore the block...from 96,00 to 97,00 and there are the org sylinder about 3,3mm - 0,5 x2 rebore = 97,00 are about 2,8-2,9mm thickness...
but the audi does have very close borespace...but you may move the syl 1 and 5 ca 2mm from the syl 2 and 4.. then you may move the sylinder 2 and 4 ca 1 mm from the sylinder 3... then you have some more borespace...

[caddy]

the sylinder walls are 6.1-6,3mm... i have done some controll of theese... 2,4 ( 5pot) have more than 6,3mm, the 2,2liter does have about 6,0 walls...
and with the 100mm 5pot custom cranc and max bore. you will have max 2771ccm...

all this number are for original bore ?
or 6.1 to 6.3 is for a 93mm bore in a 236mm block ?

[caddy]

Typical AAT stroker using 159mm uses 29.25 compression height on the pistons

AAT Deck Height: 236mm
AAT Stroke: 95.5mm
Rod Length: 159mm
Rod Wrist pin diameter: 21mm
Rod/Stroke Ratio: 1.665:1
Compression height of pistons: 29.25mm
Piston Dish Volume: -11cc
Piston Bore: 83mm
Total Displacement: 2583.6cc
7A Combustion chamber volume: 44-45cc
Compressed headgasket thickness: 1.875mm
Headgasket volume: 10cc
Compression Ratio

thanks for this interesting informations!
i have done the CR and i found 8.8, is a little higher , i need arround 8.2 / 8.5
i will go to check piston manufacturer

Max bore for cylinder wall is 83mm but it would be suicide to run that with a 95.5 crank in a 220mm block. 82mm would be your max

same answer for a 236mm block ?

[caterpillar]

the sylinder walls are 6.1-6,3mm... i have done some controll of theese... 2,4 ( 5pot) have more than 6,3mm, the 2,2liter does have about 6,0 walls...
and with the 100mm 5pot custom cranc and max bore. you will have max 2771ccm...

[Jamo]

Typical AAT stroker using 159mm uses 29.25 compression height on the pistons

AAT Deck Height: 236mm
AAT Stroke: 95.5mm
Rod Length: 159mm
Rod Wrist pin diameter: 21mm
Rod/Stroke Ratio: 1.665:1
Compression height of pistons: 29.25mm
Piston Dish Volume: -11cc
Piston Bore: 83mm
Total Displacement: 2583.6cc
7A Combustion chamber volume: 44-45cc
Compressed headgasket thickness: 1.875mm
Headgasket volume: 10cc
Compression Ratio

Max bore for cylinder wall is 83mm but it would be suicide to run that with a 95.5 crank in a 220mm block. 82mm would be your max

[caddy]

for the piston i use this math and check it on the bloc
bloc is 236
need: 95.5mm/2 ( stroke) + 159 (rod) + 28 (comp height) =234.75
with machining the bloc on gasket surface with 1mm less we are ok.
piston have special comp height to stay inside the 220mm blok with 144mm rod , so with 159mm rod in a 236mm block is same think with 1mm more i'm good ?

for bore the maximal bore is only for the gasket ? not for the thick off the cylinder wall ?
no trouble if i use a good gasket on 93mm or 92.5 ?

[Jamo]

hi all, i just have a question that i couldn't solve with reading all the thread in the forum.
i'm on a TDI bloc conversion(236mm), so 95.5mm crank and 159mm rod with special piston originaly made for 220mm bloc and 95.5mm crank.
the question is about bore , how big can i go without trouble with the thikness of the bloc beetwin the cylinder ?
any 2.6l big hp runing here ?
thanks.

You shouldn't use pistons made for the 220mm and the 95.5 crank in the 236 mm block.
It negates the point of runnin the tall deck as the compression height of the pistons is going to be way small in comparison to those made specifically for the 236mm block

82mm is the maximum you can run on the stock audi gasket, any bigger and you need to run a copper gasket or bore out the oem gasket

[caddy]

hi all, i just have a question that i couldn't solve with reading all the thread in the forum.
i'm on a TDI bloc conversion(236mm), so 95.5mm crank and 159mm rod with special piston originaly made for 220mm bloc and 95.5mm crank.
the question is about bore , how big can i go without trouble with the thikness of the bloc beetwin the cylinder ?
any 2.6l big hp runing here ?
thanks.

[GazzaG60]

the legacy turbo is a chargecooler. water based. intercooler on the AAN is not the best. fitting a cooler in a older shape is not easy. you could use a custom unit costing £££. oyu may be able to source a full legacy setup for under 100. worth looking into if you want to start on a budget.

the impreza uses an intercooler. good for upto 300 in pree 2000 wrx form. dont bother with these. they need to be mounted in a certain way.

i think maybe the legacy setup would go above the turbo at the side of the head. investigation would be needed or source a core and see where it goes. the pipes and radiator are less of an issue. water is self contained on the legacy IIRC so no tank.

[MGaz]

with that setup im currently making about 500hp. 1.9bar boost. torque id say at 400+. i will take it to the RR in a few weeks for a dyno.

stock inlet will do 400hp. wagner lots more. the difference is the piping route is so much shorter. reduction in lag a little. more flow.

charge coolers work well. the issue is space, weight, good pump, right amount of water, good core. i have experience with jabsco pumps, pwr cores along with subaru legacy.

upto 300 hp a setup off a legacy turbo will work well. small rad, bottle, core. 2 speed pump IIRC 7/12gpm. the pwr i used was a big unit for a race spec impreza.

on a budget there is simply no need to spend thousands on turbos, big block builds etc.

400hp for me is the figure most attainable from a stock motor for best value. look for a good exhaust manifold and look into a 57 trim t04e with a 0.63 hotside. think thats should do the trick with a little to spare IMO. you need to consoider rods either way i feel at this level they are on the edge.

well, if the stock AAN intake is good for 400horse powers I think I'll stick with that then. 300-400hp sounds plenty powerful for the time being, so unless I get a thirst for more power later on, no point changing the IM.

Interesting you mention the subaru legacy turbo. So your saying the standard intercooler items on a subaru turbo will be an upgrade from the stock Audi AAN parts?

shouldn't be too hard to find second hand ? As a lot of people upgrade there scoobies, so there should be plenty of standard 2nd hand parts turning up for sale? yea?

[GazzaG60]

with that setup im currently making about 500hp. 1.9bar boost. torque id say at 400+. i will take it to the RR in a few weeks for a dyno.

stock inlet will do 400hp. wagner lots more. the difference is the piping route is so much shorter. reduction in lag a little. more flow.

charge coolers work well. the issue is space, weight, good pump, right amount of water, good core. i have experience with jabsco pumps, pwr cores along with subaru legacy.

upto 300 hp a setup off a legacy turbo will work well. small rad, bottle, core. 2 speed pump IIRC 7/12gpm. the pwr i used was a big unit for a race spec impreza.

on a budget there is simply no need to spend thousands on turbos, big block builds etc.

400hp for me is the figure most attainable from a stock motor for best value. look for a good exhaust manifold and look into a 57 trim t04e with a 0.63 hotside. think thats should do the trick with a little to spare IMO. you need to consoider rods either way i feel at this level they are on the edge.

[Rusty]

Ian Simmonds owns a rally rep (stripped) on here with the original KV that weighs 1150kg, down from 1230kg, expect about 1300kg with all the turbo gubbins.

[MGaz]

If anything Smiley's estimate is under on some parts, afraid that there are very few shortcuts on these cars. The exhaust is turbo back so will be nearly £1k, you do need a Wagner EM for bigger flow, larger capacity injectors are still £300 a set, a proper turbo will still be £1k with oil lines. Don't forget this is just the engine, you'll need to upgrade the suspension and brakes, budget £2k to do it properly....

I've not decided what i'm doing about the brakes yet, but the suspension will be adjustable coilovers with Bilstain P6 dampers and D-Falkner springs with alloy race bearing top mounts.

I have the fronts ready to be fitted, just need to get the rears converted.

Torque was 330ftlbs at about 3000rpm on that run.

so 297bhp & 330lb/ft ? I can live with that for now . if the latest 'CAR' magazine I have here is correct, it states the the following:

RS2: 315bhp & 302lbft (1595kg) 0-62mph 4.8sec 162mph
SQ: 302bhp & 258lbft (1298kg) 0-62mph 4.9sec 155mph
UR 10vt: 197bhp & 210lbft (1290kg) 0-62mph 7.3sec 137mph

How heavy is my car? about 1200kg? will the 20vt lump and IC add much weight to the car? Am I looking at UR weight with the turbo engine fitted?

0-60 I've measured at 5s (you'll get close but have to use 3rd, hence not 4.5s).

0-100 <13s (aerodynamics are against you a bit, not sure, will 4th will do 100mph @ <7400?, mine is low 12s last time I measured it).

Will it do 100mph in 4th?
yea, i think my car does roughly 2nd=55mph 3rd=80mph 4th=100mph

But that's with the standard KV limiter that kicks in at about 6200rpm.. SO.. if the AAN limits at a higher 7200rpm surely the extra 1k rev limit will afford me a bit more top speed in each gear. so anyone have any idea by how much? & would I reach 60 in 2nd?

I have an RS2 intercooler and while it's not essential, it does make a difference, fitting a large IC will take work.

yea, there isn't much room behind there tbf. would a larger IC mean cutting my front bumper? would like to avoid doing that if at all poss.

Isn't '20Vcqdriver' using a 'charge cooler' on his cq? hows one of them work?

[MGaz]

depending on how you do things it can cost a lot. lag is down to the indiviidual. what do oyu call excessive lag. also changing a gear gets you away from the lag.

heres what i did. thoses costs scare me too.

aby standard block.
scat rods £200
piston skim, rod balance, weight match, head skim, new seals, clean chambers - £200
arp bolts - £100
7a cam - 50
wagner IC, inlet kit £1400 ish
wagner tubes - £320
precision sc6152e - £399

exhaust costs from smiler i think are about correct. add 500 at least as stated for bits.

then the costly -parts maybe depending on build, management and feedback. there are a number of ways to do this beit motronic with a map or standalone. my choice a few years ago was vems. at the time many were sceptics. peter was already using vems IIRC. there were only a coupel of AAN motor and the wiki was 1 sheet.

vems - 700

to tune it you need feedback from egt and AFR. depending on what you use here £300
boost control is an area of no rights to coin a jamo phrase. i use eboost2. i like it. its simple.
boost gauges again personal. i dont do cheap here so vdo is not for me.

i have a defi boost and version 2 controller. £150

So how much bhp/torque are you making with that set up ^ ?

Also, this 'Wagner Inlet manifold' .. what kind of gains are we talking if fitted to a remapped 297bhp engine?

Obviously I can assume this wagner IM is better than the AAN Inlet, what other options do i have regarding IM choices? Or is the AAN inlet quite good for most uses? as I see a few people have fitted them to there 3b/aby engines.

[GazzaG60]

depending on how you do things it can cost a lot. lag is down to the indiviidual. what do oyu call excessive lag. also changing a gear gets you away from the lag.

heres what i did. thoses costs scare me too.

aby standard block.
scat rods £200
piston skim, rod balance, weight match, head skim, new seals, clean chambers - £200
arp bolts - £100
7a cam - 50
wagner IC, inlet kit £1400 ish
wagner tubes - £320
precision sc6152e - £399

exhaust costs from smiler i think are about correct. add 500 at least as stated for bits.

then the costly -parts maybe depending on build, management and feedback. there are a number of ways to do this beit motronic with a map or standalone. my choice a few years ago was vems. at the time many were sceptics. peter was already using vems IIRC. there were only a coupel of AAN motor and the wiki was 1 sheet.

vems - 700

to tune it you need feedback from egt and AFR. depending on what you use here £300
boost control is an area of no rights to coin a jamo phrase. i use eboost2. i like it. its simple.
boost gauges again personal. i dont do cheap here so vdo is not for me.

i have a defi boost and version 2 controller. £150