GT4088R after GT35R first impressions

Finished the car this morning, after 3 weeks off the road. Delayed by work, missing fittings etc...

Started her up and took her out to make sure that everything was running well, then slowly began to push up the boost.

I only reached about 1.1 bar, fuelling was fine, although it took a gentle half hour to relearn the map after the swap and an increase in fuel pressure.

First impressions are good, the power delivery is very smooth, it's very drivable and makes good positive boost early in 6th, making pottering about easy. (I think VVTi may have something to do with this as I thought it would be significantly worse). It definately has longer legs at the top on the rev range (5.5+) than the 35, and I'm sure *hope* it will have quite a bit more grunt once I get the boost up to the 1.4 / 1.5 terratory. It may run a bit cooler too, max egt was 720, and although I didn't have the egt on the old turbo I did have some minor det issues on hot days (etc shutdown)

I have to say though that in retrospect the GT35R is a very good turbo. It doesn't develop a lot less power than this by any means but definately feels a lot more responsive. In the dry it was usable in 1st and 2nd, like a stock car, whereas the 4088R is a bit of a mess in the first two gears.

The 4088R doesnt quite have the power increase I would have liked given the extra lag... it would be a disadvantage on a normal track.

Still I'm a happy man. Rolling start killer and looking forward to Marham again.

just out of interest I am 40% through wrapping my BL 4" exhaust in heat tape... in an effort to kill off the drone between 3-3.6 k on the motorway, as well as stop my ass from heating up. Even though I have only done a bit it's definately killed a lot of the noise.. hard to quantify though after i have changed the turbo.. still when I get it all done perhaps I will have the answer..?

Great stuff Mike, makes me want mine back even more now, be great to see yours some time.

you are always welcome to pop round!

Always good to hear real world experiences of the different turbo's

Will be very interested to hear what you think once it's running decent boost. Bet it'll pull like a train!

you are always welcome to pop round!

Defo up for that could even do a vvti vs non vvti run

I hope so

It was a bit damp today so I didn't want to push my luck. It's no good expecting an Vpro to map itself when RLTC keeps cutting in.

Had the alignment done today again.. I knew it was out, the front toe was -5 degrees. I asked them to tighten it up properly this time.

Just out of interest, and have searched for this, what is a good wot egt and a danger limit?

Just out of interest, and have searched for this, what is a good wot egt and a danger limit?

Where is the sensor mounted exactly?

If it's pre turbo then 950 should be your absolute limit

Anything past 900 c (pre turbo) is getting borderline IIRC, 1000 c is asking for trouble

Defo up for that could even do a vvti vs non vvti run

as long as it's a rolling start in 6th at 1000 rpm!

My Vpro is a very safe ECU, but sometimes I feel other cars are faster just by the fact that they don't ask the engine if it's feeling ok, they just poke it with a stick!

Anything past 900 c (pre turbo) is getting borderline IIRC, 1000 c is asking for trouble

and post turbo... that would be what.. 100 degrees less?

I mounted in the first inch of downpipe, as I didn't trust apexi to build a sensor that wouldnt melt of shear off eventually.

as long as it's a rolling start in 6th at 1000 rpm!

 

My Vpro is a very safe ECU, but sometimes I feel other cars are faster just by the fact that they don't ask the engine if it's feeling ok, they just poke it with a stick!

Lol, if it's a rolling start @ 1000 I'll be using the JamieP technique to get me some boost

and post turbo... that would be what.. 100 degrees less?

 

I mounted in the first inch of downpipe, as I didn't trust apexi to build a sensor that wouldnt melt of shear off eventually.

Post turbo the general concenus is -200 c, (although I would like to see scientific proof of this i.e. 2 sensors 1 pre-turbo 1 post turbo) I don't think a simple rule of -200 c is good enough to cover all conditions.

Lol, if it's a rolling start @ 1000 I'll be using the JamieP technique to get me some boost

towtruck?

towtruck?

Nearly spat my drink out there

I just came back from my dryed out test track where I'd been pushing the boost steadily higher to 1.5bar.

Ok, maybe I misjudged it at first... it REALLY pulls.. there is a lot more there over the 35 at the top end. It's a different animal at higher boost, and higher revs, just no letup right to the rev limiter.

So I've gained top end, in 3rd gear onwards, and surprsingly the bottom end drivability is really good still, but what I'm lacking is throttle response.

Oh and the heat shielded manifold, dp and exhaust = much queieter, no drone but lots of flamage on liftoff,

Post turbo the general concenus is -200 c, (although I would like to see scientific proof of this i.e. 2 sensors 1 pre-turbo 1 post turbo) I don't think a simple rule of -200 c is good enough to cover all conditions.

A couple of members over the years have had the the EGT sensor fitted post turbo initially by the installer and then later-on, had it moved pre-turbo.....I'm one of them.

-200C is correct

Hmmm.. then my egts must be peaking at around 900.. (700 on the guage) although I have a fully insulated system now (manifold well wrapped) to contain the heat.

I have yet to get the water/meth injection system working so It will be interesting to see how far this can bring the temperature down.

Subscribed...the two setups I'm considering, whats your full setup mike?

Subscribed...the two setups I'm considering, whats your full setup mike?

http://www.mkivsupra.net/vbb/vbpicgallery.php?do=view&g=977

Interesting read Mike, I have the GT35R and often wondered how it would compare to the GT40R.

Hmmm.. then my egts must be peaking at around 900.. (700 on the guage) although I have a fully insulated system now (manifold well wrapped) to contain the heat.

 

I have yet to get the water/meth injection system working so It will be interesting to see how far this can bring the temperature down.

ive seen my egt's plumet 150 deg with water inject

ive seen my egt's plumet 150 deg with water inject

That's very impressive, always had it on my previous cars, might invest in a setup for the Supe

ive seen my egt's plumet 150 deg with water inject

Bloody hell! that's amazing. I use an agressive map on the vvti and the engine doesn't like a lot of advance compared to the non vvti, so I do get throttle shutdown on hot days, bad fuel etc,

I'm hoping the Water/Meth will be a big help. I'll post up once I get it running and let you all know what the difference is.

To answer your question nic; the 40R is a very different turbo.. there is far less immediacy in it but when she goes she goes. The 35R makes the car feel small and nippy; just what you want for a track, 1st 2nd and most of 3rd is like a motorbike engine on the 35 compared to the 40R - it's very effective if you have the traction. The 35 makes the car like a stock car with massive horsepower, very fun, nimble, responsive and devistating on track (if you can drive).

But if anything can pull away from me on the motorway now they deserve a medal, for I would not want to be sat in their passenger seat!

My car has gone from a redbull fueled teenager to a old boy on the porch with his shotgun. I like his style!

Bloody hell! that's amazing. I use an agressive map on the vvti and the engine doesn't like a lot of advance compared to the non vvti, so I do get throttle shutdown on hot days, bad fuel etc,

 

I'm hoping the Water/Meth will be a big help. I'll post up once I get it running and let you all know what the difference is.

 

To answer your question nic; the 40R is a very different turbo.. there is far less immediacy in it but when she goes she goes. The 35R makes the car feel small and nippy; just what you want for a track, 1st 2nd and most of 3rd is like a motorbike engine on the 35 compared to the 40R - it's very effective if you have the traction. The 35 makes the car like a stock car with massive horsepower, very fun, nimble, responsive and devistating on track (if you can drive).

 

But if anything can pull away from me on the motorway now they deserve a medal, for I would not want to be sat in their passenger seat!

 

My car has gone from a redbull fueled teenager to a old boy on the porch with his shotgun. I like his style!

I am of course using a big jet size for that.. but its very noticeable and well worth the investiment in my book..... I'd be careful using methanol as it could have adverse effects on lambda probe readings.. I.E reading false ones.... And we wouldn't want that now would we.

I am of course using a big jet size for that.. but its very noticeable and well worth the investiment in my book..... I'd be careful using methanol as it could have adverse effects on lambda probe readings.. I.E reading false ones.... And we wouldn't want that now would we.

Ahhh.. you the first person to say that.... will have to do some checking. 50/50 mix is what i have planned to use.

My downpipe has 3 O2 sensors in it, but still...

meth is amazing stuff on your hands.. so cold; the evaporation rate is huge. I mixed a batch up 50/50 and the container started to heat up... temp got to about 30 degrees C with bubbles on the side. Pretty meaty stuff Methanol...

Also shoving too much in the system gives you less power, so I'll have to have a play - it's a progressive controller. It's hard to quantify when not on a dyno though.

Ahhh.. you the first person to say that.... will have to do some checking. 50/50 mix is what i have planned to use.

My downpipe has 3 O2 sensors in it, but still...

meth is amazing stuff on your hands.. so cold; the evaporation rate is huge. I mixed a batch up 50/50 and the container started to heat up... temp got to about 30 degrees C with bubbles on the side. Pretty meaty stuff Methanol...

 

Also shoving too much in the system gives you less power, so I'll have to have a play - it's a progressive controller. It's hard to quantify when not on a dyno though.

Well just be careful... is what i would say..... it would be interesting to do some testing on the effects the lambda values go up and down with injecting various quanity's on methanol....