Possible Turbo Build 8v

[camgti 56]

OK, ive been doing some research over the past few weeks and this is what im looking at doing. The only thing im no to sure about is how the internals are going to cope with it.

So here goes. Im running aftermarket management and going to be using a t28 bb turbo. Going to have a manifold made up to bring the turbo next to the engine so to run short piping to an intercooler possibly along the front above the radiator and then into the inlet manifold. I have a DKZ cam i can use and am proberbly going to use about 2.75in exhaust, ill also be using correct injectors for the job. Im wanting minimal lag and a wide spread of power that can rev to 6k. Am i asking to much? Hoping for 220-230hp but torque is what im after. Is 15psi to little too much?

 

How does this sound? Ive run a warm MI16 but want over 200hp which is going to cost way to much and cant really be legal over here so thats why the turbo route..

 

Cam

[welshpug 1,622]

Sounds like you have the right ingredients and direction for that kind of power, have you seen this topic?

 

http://forum.205gtidrivers.com/index.php?showtopic=76158

 

a relatively standard build that produced very good power.

[camgti 56]

Yea did come across this one. Im wanting to bring the turbo around to the side (sort of where the battery sits) like a T16 to make a better manifold, although this one above looks great. The reason for this is to make the pipework as short as possible hopefully reducing as much lag as possible ( maby im just dreraming)

 

Cam

[TEKNOPUG 3]

On what engine?

[James_R 3]

Would guessa n 8v as there's a DKZ cam mentioned.

 

Vern managed 230BHP on a TT engine with emerald so cna't be too hard.

[TEKNOPUG 3]

I meant, XU9 or XU10?

[vern 0]

230 is easily achievable with the 1.9 engine, but the standard pistons cannot take that sort of power for long as I have found out. With a big valve head and cam, I should think over 250 is achievable on about 17psi of boost, but would recommend forged pistons for longeviety of the engine.

[camgti 56]

Engine is from an Xantia CT so i think its the XU10? 2.0l T.

[whizzer71 0]

OK, ive been doing some research over the past few weeks and this is what im looking at doing. The only thing im no to sure about is how the internals are going to cope with it.

So here goes. Im running aftermarket management and going to be using a t28 bb turbo. Going to have a manifold made up to bring the turbo next to the engine so to run short piping to an intercooler possibly along the front above the radiator and then into the inlet manifold. I have a DKZ cam i can use and am proberbly going to use about 2.75in exhaust, ill also be using correct injectors for the job. Im wanting minimal lag and a wide spread of power that can rev to 6k. Am i asking to much? Hoping for 220-230hp but torque is what im after. Is 15psi to little too much?

 

How does this sound? Ive run a warm MI16 but want over 200hp which is going to cost way to much and cant really be legal over here so thats why the turbo route..

 

Cam

 

Very laggy with T28 as spool time is dramaticaly increased,Good side is that once it has spooled up it holds full boost right across the rev range whereas the T25 spools really quick barely any lag but then tends to run out of puff !

I think that if you have longer primaries (IE by mounting the Turbo to the side) that also increases lag

 

[camgti 56]

Very laggy with T28 as spool time is dramaticaly increased,Good side is that once it has spooled up it holds full boost right across the rev range whereas the T25 spools really quick barely any lag but then tends to run out of puff !

I think that if you have longer primaries (IE by mounting the Turbo to the side) that also increases lag

 

 

 

Yea this is one of my concern but i would like to be able to mae the manifold flow as much as possible to make everything as efficient as possible making everything work together. The t25 was the other thing i was think about. What about Highflowing the t25? Or a t28 with a smaller rear housing?

 

Cam

[Tom Fenton 1,525]

The T25 and T28 are old hat now. Look for a GT25 series turbo is my advice.

[camgti 56]

Sounds Good. Ill do some research. Why are you recommending this and what cars are they on? Assuming they are only a mod for further tuning and not a standard item from some cars.

 

Cam

[camgti 56]

Im Also keen if nesessary to do some head work to make things more efficient and reliable. Maby some seat and throat work. Gas Flow? Anyone tried this?

 

Cam

[James_R 3]

Not really worth the effort on a forced induction car, the Xu10 head flows pretty well as it is.

Edited June 26, 2008 by James_R

[whizzer71 0]

Yea this is one of my concern but i would like to be able to mae the manifold flow as much as possible to make everything as efficient as possible making everything work together. The t25 was the other thing i was think about. What about Highflowing the t25? Or a t28 with a smaller rear housing?

 

Cam

 

One we used was a GT28RS .63 compressor .48 Exhaust side ,as I said laggy but when it came on OH ultimate grins all the way !,Currently using a T25 from a 200SX best one to use is from the Pulsar apparently ?.

 

[Doof 11]

Not really worth the effort on a forced induction car, the Xu10 head flows pretty well as it is.

 

Isn't that always one of the misconceptions with turbo engines? yes you can up the boost and simply deal with the extra heat but that increases lag among other side effects whereas increasing the head flow increases power without any increase in lag etc...

[GLPoomobile 958]

Isn't that always one of the misconceptions with turbo engines? yes you can up the boost and simply deal with the extra heat but that increases lag among other side effects whereas increasing the head flow increases power without any increase in lag etc...

I'm just regurgitating web based information here, but I remember reading on Dave Bakers website about this sort of thing. I think he was using it as an example for big valve heads. IIRC he was saying that the more you can improve the overall flow, the lower the actual boost pressure becomes, i.e. if you have a turbo that is doing a set amount of work, you may see 1 bar of boost pressure (for example), but by improving the overall flow (such as by using bigger valves) you reduce boost pressure, so may then see only 0.9 bar. This drop in boost pressure is not a drop in performance, it is an increase in efficiency, meaning lower temps, and you can run a smaller intercooler/charge cooler.

 

I know that on an NA engine, using bigger valves is not so simple as you also affect gas speeds etc. Is this less important (or even irrelevant) on a 'charged engine since the air is being compressed rather than sucked in to the engine? I would presume that using bigger valves with the risk of slowing gas speeds would only be an issue when off boost. Would that be right?

[saveloy 8]

GLPooobumhole, I'm a wee bit dwunk, so forgive my shortness of reply.

Yes, you are right to a degree. But when a head is flowed, the gas speed decreases in a forced induction engine. So the only way to limit the lag that causes, is to increase boost. Since the wastegate controls the boost.

So yes, off boost performance is mainly affected. And waiting 3 minutes for the oooomph can be very frustrating.

[camgti 56]

So done a bit of research on these gt25 series. They seem to have a fairly good wrap. Only little concern is that a few people are stating they run out of puff at higher revs. COnsidering im only hoping for 230Hp (maby 240) and 6000Rpm i dont think its going to be a problem. Probably relating to cars tuned to the maximum of their turbo and higher revs and possibly higher capacity engine?

 

Also taking into account the disance from the exhaust ports to the turbo, what are you thoughts on keeping the Turbs closer and to the rear of the engine using a custom manifold instead of bringing it around to the side (battery area)? My only concern was the longer piping length from the back of the turbo to get air and to feed air. Keeping it short as possible would surley reduce heat transfer (to the air being forced and sucked through the piping) and also keep minimal volume of air for assistance of reducing lag aswel?

 

Cam

[James_R 3]

I doubt you'll see much difference when you actually drive it, only really difference will be from behind the keyboard.

 

On the gas flowing the head, I was more point that spending £400 on flowing the head won't give the smae reult as spending £400 somewhere else on the build. yes you run the same power for less boost as there's less resitance to the air going in.

Hadn't heard about the increased lag, but savloy is speaking from experince not internet webmechanic mystery so there you go.

 

Cam, if you're planning to run mangement and things, why not consider a 16v head so you can play with the cam overlap?

[camgti 56]

Not sure. Just dont want the hasstle fo rebuilding another motor. Besides i dont think i need over 230hp in a 205.

[sonofsam 5]

I personally wouldn't go for headwork either, prefering to spend the money elsewhere-like an LSD, uprated clutch or good gearbox.

Edited June 28, 2008 by sonofsam

[Mattsav 1]

The Xu10 8v heads dont need a lot fo work to get an extra 15% inlet flow. Cut the seats angles correctly and blend into the port.

 

Well worth having for the minimal costs involved.

[camgti 56]

I personally wouldn't go for headwork either, prefering to spend the money elsewhere-like an LSD, uprated clutch or good gearbox.

 

Ive already got a rebuilt box with custom ratios and an LSD (quaiffe) and everything else on the car is rebuilt for more power and speed. Now all i need is the engine! Man i must admit its very frustrating not having the 205 on the road. Its like not having enough air or loosing one of your nuts...

 

 

 

Cam

[sonofsam 5]

Ive already got a rebuilt box with custom ratios and an LSD (quaiffe) and everything else on the car is rebuilt for more power and speed. Now all i need is the engine! Man i must admit its very frustrating not having the 205 on the road. Its like not having enough air or loosing one of your nuts...

 

 

 

Cam

 

 

Fair do's then!

 

Feel you pain mate, mine was off the road for nearly 2 years while I was Turboing Her.

 

Look forward to seeing more on this build in the future

 

Sam.